Merge commit 'upstream/1.2.0.d20091224'

99 files changed, 43207 insertions, 0 deletions

diff --git a/doc/user/MANIFEST b/doc/user/MANIFEST
new file mode 100644
index 0000000..ef273d3
--- /dev/null
+++ b/doc/user/MANIFEST
@@ -0,0 +1,50 @@
+actions.xml
+add-method.xml
+alias.xml
+ant.xml
+builders.xml
+builders-built-in.xml
+builders-commands.xml
+builders-writing.xml
+build-install.xml
+caching.xml
+command-line.xml
+cons.pl
+copyright.xml
+depends.xml
+environments.xml
+errors.xml
+example.xml
+factories.xml
+file-removal.xml
+hierarchy.xml
+install.xml
+java.xml
+libraries.xml
+less-simple.xml
+main.xml
+make.xml
+mergeflags.xml
+misc.xml
+nodes.xml
+output.xml
+parseconfig.xml
+parseflags.xml
+preface.xml
+python.xml
+repositories.xml
+run.xml
+scanners.xml
+sconf.xml
+separate.xml
+simple.xml
+sourcecode.xml
+tasks.xml
+tools.xml
+troubleshoot.xml
+variants.xml
+variables.xml
+SCons-win32-install-1.jpg
+SCons-win32-install-2.jpg
+SCons-win32-install-3.jpg
+SCons-win32-install-4.jpg
diff --git a/doc/user/README b/doc/user/README
new file mode 100644
index 0000000..aef479a
--- /dev/null
+++ b/doc/user/README
@@ -0,0 +1,21 @@
+# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+When adding a new file, add it to main.xml and MANIFEST.
+
+To build the .xml files from the .in files:
+  scons -D BUILDDOC=1 foo.xml
+To build the whole PDF doc from this dir, for testing:
+  scons -D ../../build/doc/PDF/scons-user.pdf 
+
+Writing examples: here's a simple template.
+
+ <scons_example name="Foo">
+   <file name="SConstruct">
+    env = Environment()
+    print env.Dump("CC")
+   </file>
+ </scons_example>
+
+ <scons_output example="Foo">
+    <scons_output_command>scons -Q</scons_output_command>
+ </scons_output>
diff --git a/doc/user/SCons-win32-install-1.jpg b/doc/user/SCons-win32-install-1.jpg
new file mode 100644
index 0000000..ecc439d
--- /dev/null
+++ b/doc/user/SCons-win32-install-1.jpg
diff --git a/doc/user/SCons-win32-install-2.jpg b/doc/user/SCons-win32-install-2.jpg
new file mode 100644
index 0000000..f468526
--- /dev/null
+++ b/doc/user/SCons-win32-install-2.jpg
diff --git a/doc/user/SCons-win32-install-3.jpg b/doc/user/SCons-win32-install-3.jpg
new file mode 100644
index 0000000..90d2ed4
--- /dev/null
+++ b/doc/user/SCons-win32-install-3.jpg
diff --git a/doc/user/SCons-win32-install-4.jpg b/doc/user/SCons-win32-install-4.jpg
new file mode 100644
index 0000000..d37973b
--- /dev/null
+++ b/doc/user/SCons-win32-install-4.jpg
diff --git a/doc/user/actions.in b/doc/user/actions.in
new file mode 100644
index 0000000..1ea5c49
--- /dev/null
+++ b/doc/user/actions.in
@@ -0,0 +1,404 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 Build actions
+
+Cons supports several types of B<build actions> that can be performed
+to construct one or more target files.  Usually, a build action is
+a construction command, that is, a command-line string that invokes
+an external command.  Cons can also execute Perl code embedded in a
+command-line string, and even supports an experimental ability to build
+a target file by executing a Perl code reference directly.
+
+A build action is usually specified as the value of a construction
+variable:
+
+  $env = new cons(
+	CCCOM         => '%CC %CFLAGS %_IFLAGS -c %< -o %>',
+	LINKCOM       => '[perl] &link_executable("%>", "%<")',
+	ARCOM         => sub { my($env, $target, @sources) = @_;
+				 # code to create an archive
+				}
+  );
+
+A build action may be associated directly with one or more target files
+via the C<Command> method; see below.
+
+=head2 Construction commands
+
+A construction command goes through expansion of construction variables
+and C<%-> pseudo-variables, as described above, to create the actual
+command line that Cons will execute to generate the target file or
+files.
+
+After substitution occurs, strings of white space are converted into
+single blanks, and leading and trailing white space is eliminated. It
+is therefore currently not possible to introduce variable length white
+space in strings passed into a command.
+
+If a multi-line command string is provided, the commands are executed
+sequentially. If any of the commands fails, then none of the rest are
+executed, and the target is not marked as updated, i.e. a new signature is
+not stored for the target.
+
+Normally, if all the commands succeed, and return a zero status (or whatever
+platform-specific indication of success is required), then a new signature
+is stored for the target. If a command erroneously reports success even
+after a failure, then Cons will assume that the target file created by that
+command is accurate and up-to-date.
+
+The first word of each command string, after expansion, is assumed to be an
+executable command looked up on the C<PATH> environment variable (which is,
+in turn, specified by the C<ENV> construction variable). If this command is
+found on the path, then the target will depend upon it: the command will
+therefore be automatically built, as necessary. It's possible to write
+multi-part commands to some shells, separated by semi-colons. Only the first
+command word will be depended upon, however, so if you write your command
+strings this way, you must either explicitly set up a dependency (with the
+C<Depends> method), or be sure that the command you are using is a system
+command which is expected to be available. If it isn't available, you will,
+of course, get an error.
+
+Cons normally prints a command before executing it.  This behavior is
+suppressed if the first character of the command is C<@>.  Note that
+you may need to separate the C<@> from the command name or escape it to
+prevent C<@cmd> from looking like an array to Perl quote operators that
+perform interpolation:
+
+  # The first command line is incorrect,
+  # because "@cp" looks like an array
+  # to the Perl qq// function.
+  # Use the second form instead.
+  Command $env 'foo', 'foo.in', qq(
+	@cp %< tempfile
+	@ cp tempfile %>
+  );
+
+If there are shell meta characters anywhere in the expanded command line,
+such as C<E<lt>>, C<E<gt>>, quotes, or semi-colon, then the command
+will actually be executed by invoking a shell. This means that a command
+such as:
+
+  cd foo
+
+alone will typically fail, since there is no command C<cd> on the path. But
+the command string:
+
+  cd $<:d; tar cf $>:f $<:f
+
+when expanded will still contain the shell meta character semi-colon, and a
+shell will be invoked to interpret the command. Since C<cd> is interpreted
+by this sub-shell, the command will execute as expected.
+
+=head2 Perl expressions
+
+If any command (even one within a multi-line command) begins with
+C<[perl]>, the remainder of that command line will be evaluated by the
+running Perl instead of being forked by the shell.  If an error occurs
+in parsing the Perl code, or if the Perl expression returns 0 or undef,
+the command will be considered to have failed.  For example, here is a
+simple command which creates a file C<foo> directly from Perl:
+
+  $env = new cons();
+  Command $env 'foo',
+    qq([perl] open(FOO,'>foo');print FOO "hi\\n"; close(FOO); 1);
+
+Note that when the command is executed, you are in the same package as
+when the F<Construct> or F<Conscript> file was read, so you can call
+Perl functions you've defined in the same F<Construct> or F<Conscript>
+file in which the C<Command> appears:
+
+  $env = new cons();
+  sub create_file {
+	my $file = shift;
+	open(FILE, ">$file");
+	print FILE "hi\n";
+	close(FILE);
+	return 1;
+  }
+  Command $env 'foo', "[perl] &create_file('%>')";
+
+The Perl string will be used to generate the signature for the derived
+file, so if you change the string, the file will be rebuilt.  The contents
+of any subroutines you call, however, are not part of the signature,
+so if you modify a called subroutine such as C<create_file> above,
+the target will I<not> be rebuilt.  Caveat user.
+
+=head2 Perl code references [EXPERIMENTAL]
+
+Cons supports the ability to create a derived file by directly executing
+a Perl code reference.  This feature is considered EXPERIMENTAL and
+subject to change in the future.
+
+A code reference may either be a named subroutine referenced by the
+usual C<\&> syntax:
+
+  sub build_output {
+	my($env, $target, @sources) = @_;
+	print "build_output building $target\n";
+	open(OUT, ">$target");
+	foreach $src (@sources) {
+	    if (! open(IN, "<$src")) {
+		print STDERR "cannot open '$src': $!\n";
+		return undef;
+	    }
+	    print OUT, <IN>;
+	}
+	close(OUT);
+	return 1;
+  }
+  Command $env 'output', \&build_output;
+
+or the code reference may be an anonymous subroutine:
+
+  Command $env 'output', sub {
+	my($env, $target, @sources) = @_;
+	print "building $target\n";
+	open(FILE, ">$target");
+	print FILE "hello\n";
+	close(FILE);
+	return 1;
+  };
+
+To build the target file, the referenced subroutine is passed, in order:
+the construction environment used to generate the target; the path
+name of the target itself; and the path names of all the source files
+necessary to build the target file.
+
+The code reference is expected to generate the target file, of course,
+but may manipulate the source and target files in any way it chooses.
+The code reference must return a false value (C<undef> or C<0>) if
+the build of the file failed.  Any true value indicates a successful
+build of the target.
+
+Building target files using code references is considered EXPERIMENTAL
+due to the following current limitations:
+
+=over 4
+
+Cons does I<not> print anything to indicate the code reference is being
+called to build the file.  The only way to give the user any indication
+is to have the code reference explicitly print some sort of "building"
+message, as in the above examples.
+
+Cons does not generate any signatures for code references, so if the
+code in the reference changes, the target will I<not> be rebuilt.
+
+Cons has no public method to allow a code reference to extract
+construction variables.  This would be good to allow generalization of
+code references based on the current construction environment, but would
+also complicate the problem of generating meaningful signatures for code
+references.
+
+=back
+
+Support for building targets via code references has been released in
+this version to encourage experimentation and the seeking of possible
+solutions to the above limitations.
+
+-->
+
+  <para>
+
+  &SCons; supports several types of &build_actions;
+  that can be performed to build one or more target files.
+  Usually, a &build_action; is a command-line string
+  that invokes an external command.
+  A build action can also be an external  command
+  specified as a list of arguments,
+  or even a Python function.
+
+  </para>
+
+  <para>
+
+  Build action objects are created by the &Action; function.
+  This function is, in fact, what &SCons; uses
+  to interpret the &action;
+  keyword argument when you call the &Builder; function.
+  So the following line that creates a simple Builder:
+
+  </para>
+
+  <sconstruct>
+    b = Builder(action = 'build < $SOURCE > $TARGET')
+  </sconstruct>
+
+  <para>
+
+  Is equivalent to:
+
+  </para>
+
+  <sconstruct>
+    b = Builder(action = Action('build < $SOURCE > $TARGET'))
+  </sconstruct>
+
+  <para>
+
+  The advantage of using the &Action; function directly
+  is that it can take a number of additional options
+  to modify the action's behavior in many useful ways.
+
+  </para>
+
+  <section>
+  <title>Command Strings as Actions</title>
+
+    <section>
+    <title>Suppressing Command-Line Printing</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+    </section>
+
+    <section>
+    <title>Ignoring Exit Status</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Argument Lists as Actions</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  <section>
+  <title>Python Functions as Actions</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  <section>
+  <title>Modifying How an Action is Printed</title>
+
+    <section>
+    <title>XXX:  the &strfunction; keyword argument</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+    </section>
+
+    <section>
+    <title>XXX:  the &cmdstr; keyword argument</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Making an Action Depend on Variable Contents:  the &varlist; keyword argument</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  <section>
+  <title>chdir=1</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  <section>
+  <title>Batch Building of Multiple Targets from Separate Sources:  the &batch_key; keyword argument</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  <section>
+  <title>Manipulating the Exit Status of an Action:  the &exitstatfunc; keyword argument</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  <!--
+
+  ???
+
+  <section>
+  <title>presub=</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/actions.xml b/doc/user/actions.xml
new file mode 100644
index 0000000..c3b8cf9
--- /dev/null
+++ b/doc/user/actions.xml
@@ -0,0 +1,404 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 Build actions
+
+Cons supports several types of B<build actions> that can be performed
+to construct one or more target files.  Usually, a build action is
+a construction command, that is, a command-line string that invokes
+an external command.  Cons can also execute Perl code embedded in a
+command-line string, and even supports an experimental ability to build
+a target file by executing a Perl code reference directly.
+
+A build action is usually specified as the value of a construction
+variable:
+
+  $env = new cons(
+	CCCOM         => '%CC %CFLAGS %_IFLAGS -c %< -o %>',
+	LINKCOM       => '[perl] &link_executable("%>", "%<")',
+	ARCOM         => sub { my($env, $target, @sources) = @_;
+				 # code to create an archive
+				}
+  );
+
+A build action may be associated directly with one or more target files
+via the C<Command> method; see below.
+
+=head2 Construction commands
+
+A construction command goes through expansion of construction variables
+and C<%-> pseudo-variables, as described above, to create the actual
+command line that Cons will execute to generate the target file or
+files.
+
+After substitution occurs, strings of white space are converted into
+single blanks, and leading and trailing white space is eliminated. It
+is therefore currently not possible to introduce variable length white
+space in strings passed into a command.
+
+If a multi-line command string is provided, the commands are executed
+sequentially. If any of the commands fails, then none of the rest are
+executed, and the target is not marked as updated, i.e. a new signature is
+not stored for the target.
+
+Normally, if all the commands succeed, and return a zero status (or whatever
+platform-specific indication of success is required), then a new signature
+is stored for the target. If a command erroneously reports success even
+after a failure, then Cons will assume that the target file created by that
+command is accurate and up-to-date.
+
+The first word of each command string, after expansion, is assumed to be an
+executable command looked up on the C<PATH> environment variable (which is,
+in turn, specified by the C<ENV> construction variable). If this command is
+found on the path, then the target will depend upon it: the command will
+therefore be automatically built, as necessary. It's possible to write
+multi-part commands to some shells, separated by semi-colons. Only the first
+command word will be depended upon, however, so if you write your command
+strings this way, you must either explicitly set up a dependency (with the
+C<Depends> method), or be sure that the command you are using is a system
+command which is expected to be available. If it isn't available, you will,
+of course, get an error.
+
+Cons normally prints a command before executing it.  This behavior is
+suppressed if the first character of the command is C<@>.  Note that
+you may need to separate the C<@> from the command name or escape it to
+prevent C<@cmd> from looking like an array to Perl quote operators that
+perform interpolation:
+
+  # The first command line is incorrect,
+  # because "@cp" looks like an array
+  # to the Perl qq// function.
+  # Use the second form instead.
+  Command $env 'foo', 'foo.in', qq(
+	@cp %< tempfile
+	@ cp tempfile %>
+  );
+
+If there are shell meta characters anywhere in the expanded command line,
+such as C<E<lt>>, C<E<gt>>, quotes, or semi-colon, then the command
+will actually be executed by invoking a shell. This means that a command
+such as:
+
+  cd foo
+
+alone will typically fail, since there is no command C<cd> on the path. But
+the command string:
+
+  cd $<:d; tar cf $>:f $<:f
+
+when expanded will still contain the shell meta character semi-colon, and a
+shell will be invoked to interpret the command. Since C<cd> is interpreted
+by this sub-shell, the command will execute as expected.
+
+=head2 Perl expressions
+
+If any command (even one within a multi-line command) begins with
+C<[perl]>, the remainder of that command line will be evaluated by the
+running Perl instead of being forked by the shell.  If an error occurs
+in parsing the Perl code, or if the Perl expression returns 0 or undef,
+the command will be considered to have failed.  For example, here is a
+simple command which creates a file C<foo> directly from Perl:
+
+  $env = new cons();
+  Command $env 'foo',
+    qq([perl] open(FOO,'>foo');print FOO "hi\\n"; close(FOO); 1);
+
+Note that when the command is executed, you are in the same package as
+when the F<Construct> or F<Conscript> file was read, so you can call
+Perl functions you've defined in the same F<Construct> or F<Conscript>
+file in which the C<Command> appears:
+
+  $env = new cons();
+  sub create_file {
+	my $file = shift;
+	open(FILE, ">$file");
+	print FILE "hi\n";
+	close(FILE);
+	return 1;
+  }
+  Command $env 'foo', "[perl] &create_file('%>')";
+
+The Perl string will be used to generate the signature for the derived
+file, so if you change the string, the file will be rebuilt.  The contents
+of any subroutines you call, however, are not part of the signature,
+so if you modify a called subroutine such as C<create_file> above,
+the target will I<not> be rebuilt.  Caveat user.
+
+=head2 Perl code references [EXPERIMENTAL]
+
+Cons supports the ability to create a derived file by directly executing
+a Perl code reference.  This feature is considered EXPERIMENTAL and
+subject to change in the future.
+
+A code reference may either be a named subroutine referenced by the
+usual C<\&> syntax:
+
+  sub build_output {
+	my($env, $target, @sources) = @_;
+	print "build_output building $target\n";
+	open(OUT, ">$target");
+	foreach $src (@sources) {
+	    if (! open(IN, "<$src")) {
+		print STDERR "cannot open '$src': $!\n";
+		return undef;
+	    }
+	    print OUT, <IN>;
+	}
+	close(OUT);
+	return 1;
+  }
+  Command $env 'output', \&build_output;
+
+or the code reference may be an anonymous subroutine:
+
+  Command $env 'output', sub {
+	my($env, $target, @sources) = @_;
+	print "building $target\n";
+	open(FILE, ">$target");
+	print FILE "hello\n";
+	close(FILE);
+	return 1;
+  };
+
+To build the target file, the referenced subroutine is passed, in order:
+the construction environment used to generate the target; the path
+name of the target itself; and the path names of all the source files
+necessary to build the target file.
+
+The code reference is expected to generate the target file, of course,
+but may manipulate the source and target files in any way it chooses.
+The code reference must return a false value (C<undef> or C<0>) if
+the build of the file failed.  Any true value indicates a successful
+build of the target.
+
+Building target files using code references is considered EXPERIMENTAL
+due to the following current limitations:
+
+=over 4
+
+Cons does I<not> print anything to indicate the code reference is being
+called to build the file.  The only way to give the user any indication
+is to have the code reference explicitly print some sort of "building"
+message, as in the above examples.
+
+Cons does not generate any signatures for code references, so if the
+code in the reference changes, the target will I<not> be rebuilt.
+
+Cons has no public method to allow a code reference to extract
+construction variables.  This would be good to allow generalization of
+code references based on the current construction environment, but would
+also complicate the problem of generating meaningful signatures for code
+references.
+
+=back
+
+Support for building targets via code references has been released in
+this version to encourage experimentation and the seeking of possible
+solutions to the above limitations.
+
+-->
+
+  <para>
+
+  &SCons; supports several types of &build_actions;
+  that can be performed to build one or more target files.
+  Usually, a &build_action; is a command-line string
+  that invokes an external command.
+  A build action can also be an external  command
+  specified as a list of arguments,
+  or even a Python function.
+
+  </para>
+
+  <para>
+
+  Build action objects are created by the &Action; function.
+  This function is, in fact, what &SCons; uses
+  to interpret the &action;
+  keyword argument when you call the &Builder; function.
+  So the following line that creates a simple Builder:
+
+  </para>
+
+  <programlisting>
+    b = Builder(action = 'build < $SOURCE > $TARGET')
+  </programlisting>
+
+  <para>
+
+  Is equivalent to:
+
+  </para>
+
+  <programlisting>
+    b = Builder(action = Action('build < $SOURCE > $TARGET'))
+  </programlisting>
+
+  <para>
+
+  The advantage of using the &Action; function directly
+  is that it can take a number of additional options
+  to modify the action's behavior in many useful ways.
+
+  </para>
+
+  <section>
+  <title>Command Strings as Actions</title>
+
+    <section>
+    <title>Suppressing Command-Line Printing</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+    </section>
+
+    <section>
+    <title>Ignoring Exit Status</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Argument Lists as Actions</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  <section>
+  <title>Python Functions as Actions</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  <section>
+  <title>Modifying How an Action is Printed</title>
+
+    <section>
+    <title>XXX:  the &strfunction; keyword argument</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+    </section>
+
+    <section>
+    <title>XXX:  the &cmdstr; keyword argument</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Making an Action Depend on Variable Contents:  the &varlist; keyword argument</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  <section>
+  <title>chdir=1</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  <section>
+  <title>Batch Building of Multiple Targets from Separate Sources:  the &batch_key; keyword argument</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  <section>
+  <title>Manipulating the Exit Status of an Action:  the &exitstatfunc; keyword argument</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  <!--
+
+  ???
+
+  <section>
+  <title>presub=</title>
+
+  <para>
+
+  XXX
+
+  </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/add-method.in b/doc/user/add-method.in
new file mode 100644
index 0000000..61f13cc
--- /dev/null
+++ b/doc/user/add-method.in
@@ -0,0 +1,127 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  The &AddMethod; function is used to add a method
+  to an environment.  It's typically used to add a "pseudo-builder,"
+  a function that looks like a &Builder; but
+  wraps up calls to multiple other &Builder;s
+  or otherwise processes its arguments
+  before calling one or more &Builder;s.
+  In the following example,
+  we want to install the program into the standard
+  <filename>/usr/bin</filename> directory hierarchy,
+  but also copy it into a local <filename>install/bin</filename>
+  directory from which a package might be built:
+
+  </para>
+
+  <scons_example name="ex1">
+     <file name="SConstruct" printme="1">
+     def install_in_bin_dirs(env, source):
+         """Install source in both bin dirs"""
+         i1 = env.Install("$BIN", source)
+         i2 = env.Install("$LOCALBIN", source)
+         return [i1[0], i2[0]] # Return a list, like a normal builder
+     env = Environment(BIN='__ROOT__/usr/bin', LOCALBIN='#install/bin')
+     env.AddMethod(install_in_bin_dirs, "InstallInBinDirs")
+     env.InstallInBinDirs(Program('hello.c')) # installs hello in both bin dirs     
+     </file>
+     <file name="hello.c">
+     int main() { printf("Hello, world!\n"); }
+     </file>
+  </scons_example>
+
+  <para>
+  This produces the following:
+  </para>
+
+  <scons_output example="ex1">
+    <scons_output_command>scons -Q /</scons_output_command>
+  </scons_output>
+
+  <para>
+
+  As mentioned, a psuedo-builder also provides more flexibility
+  in parsing arguments than you can get with a &Builder;.
+  The next example shows a pseudo-builder with a
+  named argument that modifies the filename, and a separate argument
+  for the resource file (rather than having the builder figure it out
+  by file extension).  This example also demonstrates using the global
+  &AddMethod; function to add a method to the global Environment class,
+  so it will be used in all subsequently created environments.
+
+  </para>
+
+  <scons_example name="ex2">
+     <file name="SConstruct" printme="1">
+     def BuildTestProg(env, testfile, resourcefile, testdir="tests"):
+         """Build the test program;
+         prepends "test_" to src and target,
+         and puts target into testdir."""
+         srcfile = "test_%s.c" % testfile
+         target = "%s/test_%s" % (testdir, testfile)
+         if env['PLATFORM'] == 'win32':
+             resfile = env.RES(resourcefile)
+             p = env.Program(target, [srcfile, resfile])
+         else:
+             p = env.Program(target, srcfile)
+         return p
+     AddMethod(Environment, BuildTestProg)
+
+     env = Environment()
+     env.BuildTestProg('stuff', resourcefile='res.rc')
+     </file>
+     <file name="test_stuff.c">
+     int main() { printf("Hello, world!\n"); }
+     </file>
+     <file name="res.rc">
+     res.rc
+     </file>
+  </scons_example>
+
+  <para>
+  This produces the following on Linux:
+  </para>
+
+  <scons_output example="ex2">
+    <scons_output_command>scons -Q</scons_output_command>
+  </scons_output>
+
+  <para>
+  And the following on Windows:
+  </para>
+
+  <scons_output example="ex2" os="win32">
+    <scons_output_command>scons -Q</scons_output_command>
+  </scons_output>
+
+  <para>
+  Using &AddMethod; is better than just adding an instance method
+  to a &consenv; because it gets called as a proper method,
+  and because &AddMethod; provides for copying the method
+  to any clones of the &consenv; instance.
+  </para>
diff --git a/doc/user/add-method.xml b/doc/user/add-method.xml
new file mode 100644
index 0000000..761765f
--- /dev/null
+++ b/doc/user/add-method.xml
@@ -0,0 +1,135 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  The &AddMethod; function is used to add a method
+  to an environment.  It's typically used to add a "pseudo-builder,"
+  a function that looks like a &Builder; but
+  wraps up calls to multiple other &Builder;s
+  or otherwise processes its arguments
+  before calling one or more &Builder;s.
+  In the following example,
+  we want to install the program into the standard
+  <filename>/usr/bin</filename> directory hierarchy,
+  but also copy it into a local <filename>install/bin</filename>
+  directory from which a package might be built:
+
+  </para>
+
+  <programlisting>
+     def install_in_bin_dirs(env, source):
+         """Install source in both bin dirs"""
+         i1 = env.Install("$BIN", source)
+         i2 = env.Install("$LOCALBIN", source)
+         return [i1[0], i2[0]] # Return a list, like a normal builder
+     env = Environment(BIN='/usr/bin', LOCALBIN='#install/bin')
+     env.AddMethod(install_in_bin_dirs, "InstallInBinDirs")
+     env.InstallInBinDirs(Program('hello.c')) # installs hello in both bin dirs     
+  </programlisting>
+
+  <para>
+  This produces the following:
+  </para>
+
+  <screen>
+    % <userinput>scons -Q /</userinput>
+    cc -o hello.o -c hello.c
+    cc -o hello hello.o
+    Install file: "hello" as "/usr/bin/hello"
+    Install file: "hello" as "install/bin/hello"
+  </screen>
+
+  <para>
+
+  As mentioned, a psuedo-builder also provides more flexibility
+  in parsing arguments than you can get with a &Builder;.
+  The next example shows a pseudo-builder with a
+  named argument that modifies the filename, and a separate argument
+  for the resource file (rather than having the builder figure it out
+  by file extension).  This example also demonstrates using the global
+  &AddMethod; function to add a method to the global Environment class,
+  so it will be used in all subsequently created environments.
+
+  </para>
+
+  <programlisting>
+     def BuildTestProg(env, testfile, resourcefile, testdir="tests"):
+         """Build the test program;
+         prepends "test_" to src and target,
+         and puts target into testdir."""
+         srcfile = "test_%s.c" % testfile
+         target = "%s/test_%s" % (testdir, testfile)
+         if env['PLATFORM'] == 'win32':
+             resfile = env.RES(resourcefile)
+             p = env.Program(target, [srcfile, resfile])
+         else:
+             p = env.Program(target, srcfile)
+         return p
+     AddMethod(Environment, BuildTestProg)
+
+     env = Environment()
+     env.BuildTestProg('stuff', resourcefile='res.rc')
+  </programlisting>
+
+  <para>
+  This produces the following on Linux:
+  </para>
+
+  <screen>
+    % <userinput>scons -Q</userinput>
+    cc -o test_stuff.o -c test_stuff.c
+    cc -o tests/test_stuff test_stuff.o
+  </screen>
+
+  <para>
+  And the following on Windows:
+  </para>
+
+  <screen>
+    C:\><userinput>scons -Q</userinput>
+    
+    scons: warning: No installed VCs
+    File "&lt;stdin&gt;", line 67, in __call__
+    
+    scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+    File "&lt;stdin&gt;", line 67, in __call__
+    
+    scons: warning: No installed VCs
+    File "&lt;stdin&gt;", line 67, in __call__
+    
+    scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+    File "&lt;stdin&gt;", line 67, in __call__
+    rc /fores.res res.rc
+    cl /Fotest_stuff.obj /c test_stuff.c /nologo
+    link /nologo /OUT:tests\test_stuff.exe test_stuff.obj res.res
+  </screen>
+
+  <para>
+  Using &AddMethod; is better than just adding an instance method
+  to a &consenv; because it gets called as a proper method,
+  and because &AddMethod; provides for copying the method
+  to any clones of the &consenv; instance.
+  </para>
diff --git a/doc/user/alias.in b/doc/user/alias.in
new file mode 100644
index 0000000..45a1534
--- /dev/null
+++ b/doc/user/alias.in
@@ -0,0 +1,102 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  We've already seen how you can use the &Alias;
+  function to create a target named <literal>install</literal>:
+
+  </para>
+
+  <scons_example name="ex1">
+     <file name="SConstruct" printme="1">
+     env = Environment()
+     hello = env.Program('hello.c')
+     env.Install('__ROOT__/usr/bin', hello)
+     env.Alias('install', '__ROOT__/usr/bin')
+     </file>
+     <file name="hello.c">
+     int main() { printf("Hello, world!\n"); }
+     </file>
+  </scons_example>
+
+  <para>
+
+  You can then use this alias on the command line
+  to tell &SCons; more naturally that you want to install files:
+
+  </para>
+
+  <scons_output example="ex1" os="posix">
+     <scons_output_command>scons -Q install</scons_output_command>
+  </scons_output>
+
+  <para>
+
+  Like other &Builder; methods, though,
+  the &Alias; method returns an object
+  representing the alias being built.
+  You can then use this object as input to anothother &Builder;.
+  This is especially useful if you use such an object
+  as input to another call to the &Alias; &Builder;,
+  allowing you to create a hierarchy
+  of nested aliases:
+
+  </para>
+
+  <scons_example name="ex2">
+     <file name="SConstruct" printme="1">
+     env = Environment()
+     p = env.Program('foo.c')
+     l = env.Library('bar.c')
+     env.Install('__ROOT__/usr/bin', p)
+     env.Install('__ROOT__/usr/lib', l)
+     ib = env.Alias('install-bin', '__ROOT__/usr/bin')
+     il = env.Alias('install-lib', '__ROOT__/usr/lib')
+     env.Alias('install', [ib, il])
+     </file>
+     <file name="foo.c">
+     int main() { printf("foo.c\n"); }
+     </file>
+     <file name="bar.c">
+     void bar() { printf("bar.c\n"); }
+     </file>
+  </scons_example>
+
+  <para>
+
+  This example defines separate <literal>install</literal>,
+  <literal>install-bin</literal>,
+  and <literal>install-lib</literal> aliases,
+  allowing you finer control over what gets installed:
+
+  </para>
+
+  <scons_output example="ex2" os="posix">
+     <scons_output_command>scons -Q install-bin</scons_output_command>
+     <scons_output_command>scons -Q install-lib</scons_output_command>
+     <scons_output_command>scons -Q -c __ROOT__/</scons_output_command>
+     <scons_output_command>scons -Q install</scons_output_command>
+  </scons_output>
diff --git a/doc/user/alias.xml b/doc/user/alias.xml
new file mode 100644
index 0000000..04ebd5f
--- /dev/null
+++ b/doc/user/alias.xml
@@ -0,0 +1,112 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  We've already seen how you can use the &Alias;
+  function to create a target named <literal>install</literal>:
+
+  </para>
+
+  <programlisting>
+     env = Environment()
+     hello = env.Program('hello.c')
+     env.Install('/usr/bin', hello)
+     env.Alias('install', '/usr/bin')
+  </programlisting>
+
+  <para>
+
+  You can then use this alias on the command line
+  to tell &SCons; more naturally that you want to install files:
+
+  </para>
+
+  <screen>
+     % <userinput>scons -Q install</userinput>
+     cc -o hello.o -c hello.c
+     cc -o hello hello.o
+     Install file: "hello" as "/usr/bin/hello"
+  </screen>
+
+  <para>
+
+  Like other &Builder; methods, though,
+  the &Alias; method returns an object
+  representing the alias being built.
+  You can then use this object as input to anothother &Builder;.
+  This is especially useful if you use such an object
+  as input to another call to the &Alias; &Builder;,
+  allowing you to create a hierarchy
+  of nested aliases:
+
+  </para>
+
+  <programlisting>
+     env = Environment()
+     p = env.Program('foo.c')
+     l = env.Library('bar.c')
+     env.Install('/usr/bin', p)
+     env.Install('/usr/lib', l)
+     ib = env.Alias('install-bin', '/usr/bin')
+     il = env.Alias('install-lib', '/usr/lib')
+     env.Alias('install', [ib, il])
+  </programlisting>
+
+  <para>
+
+  This example defines separate <literal>install</literal>,
+  <literal>install-bin</literal>,
+  and <literal>install-lib</literal> aliases,
+  allowing you finer control over what gets installed:
+
+  </para>
+
+  <screen>
+     % <userinput>scons -Q install-bin</userinput>
+     cc -o foo.o -c foo.c
+     cc -o foo foo.o
+     Install file: "foo" as "/usr/bin/foo"
+     % <userinput>scons -Q install-lib</userinput>
+     cc -o bar.o -c bar.c
+     ar rc libbar.a bar.o
+     ranlib libbar.a
+     Install file: "libbar.a" as "/usr/lib/libbar.a"
+     % <userinput>scons -Q -c /</userinput>
+     Removed foo.o
+     Removed foo
+     Removed /usr/bin/foo
+     Removed bar.o
+     Removed libbar.a
+     Removed /usr/lib/libbar.a
+     % <userinput>scons -Q install</userinput>
+     cc -o foo.o -c foo.c
+     cc -o foo foo.o
+     Install file: "foo" as "/usr/bin/foo"
+     cc -o bar.o -c bar.c
+     ar rc libbar.a bar.o
+     ranlib libbar.a
+     Install file: "libbar.a" as "/usr/lib/libbar.a"
+  </screen>
diff --git a/doc/user/ant.in b/doc/user/ant.in
new file mode 100644
index 0000000..41b441d
--- /dev/null
+++ b/doc/user/ant.in
@@ -0,0 +1,52 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+   XXX
+
+ </para>
+
+ <section>
+ <title>Differences Between &Ant; and &SCons;</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+ </section>
+
+ <section>
+ <title>Advantages of &SCons; Over &Ant;</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+ </section>
diff --git a/doc/user/ant.xml b/doc/user/ant.xml
new file mode 100644
index 0000000..41b441d
--- /dev/null
+++ b/doc/user/ant.xml
@@ -0,0 +1,52 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+   XXX
+
+ </para>
+
+ <section>
+ <title>Differences Between &Ant; and &SCons;</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+ </section>
+
+ <section>
+ <title>Advantages of &SCons; Over &Ant;</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+ </section>
diff --git a/doc/user/build-install.in b/doc/user/build-install.in
new file mode 100644
index 0000000..ab289b1
--- /dev/null
+++ b/doc/user/build-install.in
@@ -0,0 +1,719 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  This chapter will take you through the basic steps
+  of installing &SCons; on your system,
+  and building &SCons; if you don't have a
+  pre-built package available
+  (or simply prefer the flexibility of building it yourself).
+  Before that, however, this chapter will also describe the basic steps
+  involved in installing Python on your system,
+  in case that is necessary.
+  Fortunately, both &SCons; and Python
+  are very easy to install on almost any system,
+  and Python already comes installed on many systems.
+
+  </para>
+
+  <!--
+
+  <para>
+
+  Lastly, this chapter also contains a section that
+  provides a brief overview of the Python programming language,
+  which is the language used to implement &SCons;,
+  and which forms the basis of the &SCons; configuration files.
+  Becoming familiar with some Python concepts will make it easier
+  to understand many of the examples in this User's Guide.
+  Nevertheless, it <emphasis>is</emphasis> possible
+  to configure simple &SCons; builds without knowing Python,
+  so you can skip this section if you
+  want to dive in and pick up things
+  by example- -or, of course, if you are 
+  already familiar with Python.
+
+  </para>
+
+  -->
+
+  <section>
+  <title>Installing Python</title>
+
+    <para>
+
+    Because &SCons; is written in Python,
+    you must obviously have Python installed on your system
+    to use &SCons;.
+    Before you try to install Python,
+    you should check to see if Python is already
+    available on your system  by typing
+    <userinput>python -V</userinput>
+    (capital 'V')
+    or
+    <userinput>python --version</userinput>
+    at your system's command-line prompt.
+
+    </para>
+
+    <screen>
+       $ <userinput>python -V</userinput>
+       Python 2.5.1
+    </screen>
+
+    <para>
+
+    And on a Windows system with Python installed:
+
+    </para>
+
+    <screen>
+       C:\><userinput>python -V</userinput>
+       Python 2.5.1
+    </screen>
+
+    <para>
+
+    If Python is not installed on your system,
+    you will see an error message
+    stating something like "command not found"
+    (on UNIX or Linux)
+    or "'python' is not recognized
+    as an internal or external command, operable progam or batch file"
+    (on Windows).
+    In that case, you need to install Python
+    before you can install &SCons;.
+
+    </para>
+
+    <para>
+
+    (Note that the <option>-V</option> option
+    was added to Python version 2.0,
+    so if your system only has an earlier version available
+    you may see an
+    <literal>"Unknown option: -V"</literal>
+    error message.)
+
+    </para>
+
+    <para>
+
+    The standard location for information
+    about downloading and installing Python is
+    <ulink url="http://www.python.org/download/">http://www.python.org/download/</ulink>.
+    See that page for information about
+    how to download and install Python on your system.
+
+    </para>
+
+    <para>
+
+    &SCons; will work with any version of Python from 1.5.2 or later.
+    If you need to install Python and have a choice,
+    we recommend using the most recent Python 2.5 version available.
+    Python 2.5 has significant improvements
+    that help speed up the performance of &SCons;.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Installing &SCons; From Pre-Built Packages</title>
+
+    <para>
+
+    &SCons; comes pre-packaged for installation on a number of systems,
+    including Linux and Windows systems.
+    You do not need to read this entire section,
+    you should need to read only the section
+    appropriate to the type of system you're running on.
+
+    </para>
+
+    <section>
+    <title>Installing &SCons; on Red Hat (and Other RPM-based) Linux Systems</title>
+
+      <para>
+
+      &SCons; comes in RPM (Red Hat Package Manager) format,
+      pre-built and ready to install on Red Hat Linux,
+      Fedora,
+      or any other Linux distribution that uses RPM.
+      Your distribution may
+      already have an &SCons; RPM built specifically for it;
+      many do, including SUSE, Mandrake and Fedora.
+      You can check for the availability of an &SCons; RPM
+      on your distribution's download servers,
+      or by consulting an RPM search site like
+      <ulink url="http://www.rpmfind.net/">http://www.rpmfind.net/</ulink> or
+      <ulink url="http://rpm.pbone.net/">http://rpm.pbone.net/</ulink>.
+
+      </para>
+
+      <para>
+
+      If your distribution supports installation via
+      <application>yum</application>,
+      you should be able to install &SCons; by running:
+
+      </para>
+
+      <screen>
+        # <userinput>yum install scons</userinput>
+      </screen>
+
+      <para>
+
+      If your Linux distribution does not already have
+      a specific &SCons; RPM file,
+      you can download and install from the
+      generic RPM provided by the &SCons; project.
+      This will install the 
+      SCons script(s) in <filename>/usr/bin</filename>,
+      and the SCons library modules in
+      <filename>/usr/lib/scons</filename>.
+
+      </para>
+
+      <para>
+
+      To install from the command line, simply download the
+      appropriate <filename>.rpm</filename> file,
+      and then run:
+
+      </para>
+
+      <screen>
+        # <userinput>rpm -Uvh scons-1.2.0.d20091224-1.noarch.rpm</userinput>
+      </screen>
+
+      <para>
+
+      Or, you can use a graphical RPM package manager.
+      See your package manager application's documention
+      for specific instructions about
+      how to use it to install a downloaded RPM.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Installing &SCons; on Debian Linux Systems</title>
+
+      <para>
+
+      Debian Linux systems use a different package management
+      format that also makes it very easy to install &SCons;.
+
+      </para>
+
+      <para>
+
+      If your system is connected to the Internet,
+      you can install the latest official Debian package
+      by running:
+
+      </para>
+
+      <screen>
+        # <userinput>apt-get install scons</userinput>
+      </screen>
+
+      <!--
+
+      <para>
+
+      Alternatively,
+      you can download the Debian package built
+      by the &SCons; project
+      and install it manually by running:
+
+      </para>
+
+      <screen>
+        # <userinput>db-XXX scons-*.deb</userinput>
+      </screen>
+
+      -->
+
+    </section>
+
+    <section>
+    <title>Installing &SCons; on Windows Systems</title>
+
+      <para>
+
+      &SCons; provides a Windows installer
+      that makes installation extremely easy.
+      Download the <filename>scons-1.2.0.d20091224.win32.exe</filename>
+      file from the &SCons; download page at
+      <ulink url="http://www.scons.org/download.php">http://www.scons.org/download.php</ulink>.
+      Then all you need to do is execute the file
+      (usually by clicking on its icon in Windows Explorer).
+      These will take you through a small
+      sequence of windows that will install
+      &SCons; on your system.
+
+      <!--
+      Things are a little more complicated
+      if you are using the Cygwin version of Python.
+      This is because Cygwin
+      tries to make a Windows system look more
+      POSIX-like (or UNIX-like or Linux-like, if you prefer)
+      by having the Cygwin utilities,
+      including Cygwin Python,
+      interpret file name arguments on the command line
+      using the forward-slash (<filename>/</filename>)
+      as the directory separator,
+      instead of the normal Windows behavior of the
+      backslash (<filename>\</filename>) as the directory separator.
+      -->
+
+      </para>
+
+      <!--
+
+      <section>
+      <title>Installing &SCons; on Windows Systems Without Cygwin Python</title>
+
+        <para>
+
+        XXX
+
+        </para>
+
+      </section>
+
+      <section>
+      <title>Installing &SCons; on Windows Systems With Cygwin Python</title>
+
+        <para>
+
+        XXX
+
+        </para>
+
+      </section>
+
+      -->
+
+      <!--
+
+      XXX - don't have the kinks worked out on how to
+      get these to display properly in all formats,
+      so comment them out for now.
+
+      <screenshot>
+      <mediaobject>
+        <imageobject>
+          <imagedata fileref="SCons-win32-install-1.jpg" format="jpg" align="center">
+        </imageobject>
+      </mediaobject>
+      </screenshot>
+
+      <screenshot>
+      <mediaobject>
+        <imageobject>
+          <imagedata fileref="SCons-win32-install-2.jpg" format="jpg" align="center">
+        </imageobject>
+      </mediaobject>
+      </screenshot>
+
+      <screenshot>
+      <mediaobject>
+        <imageobject>
+          <imagedata fileref="SCons-win32-install-3.jpg" format="jpg" align="center">
+        </imageobject>
+      </mediaobject>
+      </screenshot>
+
+      <screenshot>
+      <mediaobject>
+        <imageobject>
+          <imagedata fileref="SCons-win32-install-4.jpg" format="jpg" align="center">
+        </imageobject>
+      </mediaobject>
+      </screenshot>
+
+      -->
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Building and Installing &SCons; on Any System</title>
+
+    <para>
+
+    If a pre-built &SCons; package is not available for your system,
+    then you can still easily build and install &SCons; using the native
+    Python <filename>distutils</filename> package.
+
+    </para>
+
+    <para>
+
+    The first step is to download either the
+    <filename>scons-1.2.0.d20091224.tar.gz</filename>
+    or <filename>scons-1.2.0.d20091224.zip</filename>,
+    which are available from the SCons download page at
+    <ulink url="http://www.scons.org/download.html">http://www.scons.org/download.html</ulink>.
+
+    </para>
+
+    <para>
+
+    Unpack the archive you downloaded,
+    using a utility like <application>tar</application>
+    on Linux or UNIX,
+    or <application>WinZip</application> on Windows.
+    This will create a directory called
+    <filename>scons-1.2.0.d20091224</filename>,
+    usually in your local directory.
+    Then change your working directory to that directory
+    and install &SCons; by executing the following commands:
+
+    </para>
+
+    <screen>
+      # <userinput>cd scons-1.2.0.d20091224</userinput>
+      # <userinput>python setup.py install</userinput>
+    </screen>
+
+    <para>
+
+    This will build &SCons;,
+    install the &scons; script
+    in the default system scripts directory
+    (<filename>/usr/local/bin</filename> or
+    <filename>C:\Python25\Scripts</filename>),
+    and will install the &SCons; build engine
+    in an appropriate stand-alone library directory
+    (<filename>/usr/local/lib/scons</filename> or
+    <filename>C:\Python25\scons</filename>).
+    Because these are system directories,
+    you may need root (on Linux or UNIX) or Administrator (on Windows)
+    privileges to install &SCons; like this.
+
+    </para>
+
+    <!--
+
+    <section>
+    <title>Building and Installing &SCons; in the Standard Python Library Directories</title>
+
+      <para>
+
+      XXX
+
+      </para>
+
+    </section>
+
+    -->
+
+    <section>
+    <title>Building and Installing Multiple Versions of &SCons; Side-by-Side</title>
+
+      <para>
+
+      The &SCons; <filename>setup.py</filename> script
+      has some extensions that support
+      easy installation of multiple versions of &SCons;
+      in side-by-side locations.
+      This makes it easier to download and
+      experiment with different versions of &SCons;
+      before moving your official build process to a new version,
+      for example.
+
+      </para>
+
+      <para>
+
+      To install &SCons; in a version-specific location,
+      add the <option>--version-lib</option> option
+      when you call <filename>setup.py</filename>:
+
+      </para>
+
+      <screen>
+        # <userinput>python setup.py install --version-lib</userinput>
+      </screen>
+
+      <para>
+
+      This will install the &SCons; build engine
+      in the
+      <filename>/usr/lib/scons-1.2.0.d20091224</filename>
+      or
+      <filename>C:\Python25\scons-1.2.0.d20091224</filename>
+      directory, for example.
+
+      </para>
+
+      <para>
+
+      If you use the <option>--version-lib</option> option
+      the first time you install &SCons;,
+      you do not need to specify it each time you install
+      a new version.
+      The &SCons; <filename>setup.py</filename> script
+      will detect the version-specific directory name(s)
+      and assume you want to install all versions
+      in version-specific directories.
+      You can override that assumption in the future
+      by explicitly specifying the <option>--standalone-lib</option> option.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Installing &SCons; in Other Locations</title>
+
+      <para>
+
+      You can install &SCons; in locations other than
+      the default by specifying the <option>--prefix=</option> option:
+
+      </para>
+
+      <screen>
+        # <userinput>python setup.py install --prefix=/opt/scons</userinput>
+      </screen>
+
+      <para>
+
+      This would
+      install the <application>scons</application> script in
+      <filename>/opt/scons/bin</filename>
+      and the build engine in 
+      <filename>/opt/scons/lib/scons</filename>,
+
+      </para>
+
+      <para>
+
+      Note that you can specify both the <option>--prefix=</option>
+      and the <option>--version-lib</option> options
+      at the same type,
+      in which case <filename>setup.py</filename>
+      will install the build engine
+      in a version-specific directory
+      relative to the specified prefix.
+      Adding <option>--version-lib</option> to the
+      above example would install the build engine in
+      <filename>/opt/scons/lib/scons-1.2.0.d20091224</filename>.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Building and Installing &SCons; Without Administrative Privileges</title>
+
+      <para>
+
+      If you don't have the right privileges to install &SCons;
+      in a system location,
+      simply use the <literal>--prefix=</literal> option
+      to install it in a location of your choosing.
+      For example,
+      to install &SCons; in appropriate locations
+      relative to the user's <literal>$HOME</literal> directory,
+      the &scons; script in
+      <filename>$HOME/bin</filename>
+      and the build engine in 
+      <filename>$HOME/lib/scons</filename>,
+      simply type:
+
+      </para>
+
+      <screen>
+        $ <userinput>python setup.py install --prefix=$HOME</userinput>
+      </screen>
+
+      <para>
+
+      You may, of course, specify any other location you prefer,
+      and may use the <option>--version-lib</option> option
+      if you would like to install version-specific directories
+      relative to the specified prefix.
+
+      </para>
+
+      <para>
+
+      This can also be used to experiment with a newer
+      version of &SCons; than the one installed
+      in your system locations.
+      Of course, the location in which you install the
+      newer version of the &scons; script
+      (<filename>$HOME/bin</filename> in the above example)
+      must be configured in your &PATH; variable
+      before the directory containing
+      the system-installed version
+      of the &scons; script.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Python Basics</title>
+
+    <para>
+
+    This section will provide a brief overview of
+    the Python programming language.
+    Skip this section if you are already familiar with Python
+    (or you're really intent on diving into &SCons;
+    and just picking up things as you go).
+
+    </para>
+
+    <para>
+
+    Python has a lot of good
+    documentation freely available on-line
+    to help you get started.
+    The standard tutorial is available at XXX.
+
+
+    </para>
+
+    <para>
+
+    Python is very easy to pick up.
+
+    </para>
+
+    <para>
+
+    Python variables must be assigned to before they can be referenced.
+
+    </para>
+
+    <para>
+
+    Assignment is like most programming languages:
+
+    x = 1 + 2
+    z = 3 * x
+
+    </para>
+
+    <para>
+
+    Function calls look like most language function calls:
+
+    a = f(g)
+
+    </para>
+
+    <para>
+
+    Define functions like so:
+
+        def func(arg1, arg2):
+            return arg1 * arg 2
+
+    The number of parameters
+
+    </para>
+
+    <para>
+
+    Strings can be enclosed in single quotes or double quotes,
+    backslashes are used to escape characters,
+    triple-quote syntax lets you include quotes and newlines,
+    raw strings begin with 'r'.
+
+    </para>
+
+    <para>
+
+    Lists are enclosed in square brackets,
+    list items are separated by commas.
+    List references use square brackets and integer index values,
+    slice notation lets you select, delete or replace a range.
+
+    </para>
+
+    <para>
+
+    Dictionaries (hashes) are enclosed in curly brackets,
+    : separates keys from values,
+    , separates items.
+    Dictionary values are referenced using square brackets.
+
+    </para>
+
+    <para>
+
+    Access class attributes (including methods) using a '.'.
+
+    </para>
+
+    <para>
+
+    if: statements look like
+
+    elif: statements look like
+
+    else: statements look like
+
+    </para>
+
+    <para>
+
+    for: statements look like
+
+    while: statements look like
+
+    break statements look like
+    
+    continue statements look like
+
+    </para>
+
+    <para>
+
+    pass
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/build-install.xml b/doc/user/build-install.xml
new file mode 100644
index 0000000..ab289b1
--- /dev/null
+++ b/doc/user/build-install.xml
@@ -0,0 +1,719 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  This chapter will take you through the basic steps
+  of installing &SCons; on your system,
+  and building &SCons; if you don't have a
+  pre-built package available
+  (or simply prefer the flexibility of building it yourself).
+  Before that, however, this chapter will also describe the basic steps
+  involved in installing Python on your system,
+  in case that is necessary.
+  Fortunately, both &SCons; and Python
+  are very easy to install on almost any system,
+  and Python already comes installed on many systems.
+
+  </para>
+
+  <!--
+
+  <para>
+
+  Lastly, this chapter also contains a section that
+  provides a brief overview of the Python programming language,
+  which is the language used to implement &SCons;,
+  and which forms the basis of the &SCons; configuration files.
+  Becoming familiar with some Python concepts will make it easier
+  to understand many of the examples in this User's Guide.
+  Nevertheless, it <emphasis>is</emphasis> possible
+  to configure simple &SCons; builds without knowing Python,
+  so you can skip this section if you
+  want to dive in and pick up things
+  by example- -or, of course, if you are 
+  already familiar with Python.
+
+  </para>
+
+  -->
+
+  <section>
+  <title>Installing Python</title>
+
+    <para>
+
+    Because &SCons; is written in Python,
+    you must obviously have Python installed on your system
+    to use &SCons;.
+    Before you try to install Python,
+    you should check to see if Python is already
+    available on your system  by typing
+    <userinput>python -V</userinput>
+    (capital 'V')
+    or
+    <userinput>python --version</userinput>
+    at your system's command-line prompt.
+
+    </para>
+
+    <screen>
+       $ <userinput>python -V</userinput>
+       Python 2.5.1
+    </screen>
+
+    <para>
+
+    And on a Windows system with Python installed:
+
+    </para>
+
+    <screen>
+       C:\><userinput>python -V</userinput>
+       Python 2.5.1
+    </screen>
+
+    <para>
+
+    If Python is not installed on your system,
+    you will see an error message
+    stating something like "command not found"
+    (on UNIX or Linux)
+    or "'python' is not recognized
+    as an internal or external command, operable progam or batch file"
+    (on Windows).
+    In that case, you need to install Python
+    before you can install &SCons;.
+
+    </para>
+
+    <para>
+
+    (Note that the <option>-V</option> option
+    was added to Python version 2.0,
+    so if your system only has an earlier version available
+    you may see an
+    <literal>"Unknown option: -V"</literal>
+    error message.)
+
+    </para>
+
+    <para>
+
+    The standard location for information
+    about downloading and installing Python is
+    <ulink url="http://www.python.org/download/">http://www.python.org/download/</ulink>.
+    See that page for information about
+    how to download and install Python on your system.
+
+    </para>
+
+    <para>
+
+    &SCons; will work with any version of Python from 1.5.2 or later.
+    If you need to install Python and have a choice,
+    we recommend using the most recent Python 2.5 version available.
+    Python 2.5 has significant improvements
+    that help speed up the performance of &SCons;.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Installing &SCons; From Pre-Built Packages</title>
+
+    <para>
+
+    &SCons; comes pre-packaged for installation on a number of systems,
+    including Linux and Windows systems.
+    You do not need to read this entire section,
+    you should need to read only the section
+    appropriate to the type of system you're running on.
+
+    </para>
+
+    <section>
+    <title>Installing &SCons; on Red Hat (and Other RPM-based) Linux Systems</title>
+
+      <para>
+
+      &SCons; comes in RPM (Red Hat Package Manager) format,
+      pre-built and ready to install on Red Hat Linux,
+      Fedora,
+      or any other Linux distribution that uses RPM.
+      Your distribution may
+      already have an &SCons; RPM built specifically for it;
+      many do, including SUSE, Mandrake and Fedora.
+      You can check for the availability of an &SCons; RPM
+      on your distribution's download servers,
+      or by consulting an RPM search site like
+      <ulink url="http://www.rpmfind.net/">http://www.rpmfind.net/</ulink> or
+      <ulink url="http://rpm.pbone.net/">http://rpm.pbone.net/</ulink>.
+
+      </para>
+
+      <para>
+
+      If your distribution supports installation via
+      <application>yum</application>,
+      you should be able to install &SCons; by running:
+
+      </para>
+
+      <screen>
+        # <userinput>yum install scons</userinput>
+      </screen>
+
+      <para>
+
+      If your Linux distribution does not already have
+      a specific &SCons; RPM file,
+      you can download and install from the
+      generic RPM provided by the &SCons; project.
+      This will install the 
+      SCons script(s) in <filename>/usr/bin</filename>,
+      and the SCons library modules in
+      <filename>/usr/lib/scons</filename>.
+
+      </para>
+
+      <para>
+
+      To install from the command line, simply download the
+      appropriate <filename>.rpm</filename> file,
+      and then run:
+
+      </para>
+
+      <screen>
+        # <userinput>rpm -Uvh scons-1.2.0.d20091224-1.noarch.rpm</userinput>
+      </screen>
+
+      <para>
+
+      Or, you can use a graphical RPM package manager.
+      See your package manager application's documention
+      for specific instructions about
+      how to use it to install a downloaded RPM.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Installing &SCons; on Debian Linux Systems</title>
+
+      <para>
+
+      Debian Linux systems use a different package management
+      format that also makes it very easy to install &SCons;.
+
+      </para>
+
+      <para>
+
+      If your system is connected to the Internet,
+      you can install the latest official Debian package
+      by running:
+
+      </para>
+
+      <screen>
+        # <userinput>apt-get install scons</userinput>
+      </screen>
+
+      <!--
+
+      <para>
+
+      Alternatively,
+      you can download the Debian package built
+      by the &SCons; project
+      and install it manually by running:
+
+      </para>
+
+      <screen>
+        # <userinput>db-XXX scons-*.deb</userinput>
+      </screen>
+
+      -->
+
+    </section>
+
+    <section>
+    <title>Installing &SCons; on Windows Systems</title>
+
+      <para>
+
+      &SCons; provides a Windows installer
+      that makes installation extremely easy.
+      Download the <filename>scons-1.2.0.d20091224.win32.exe</filename>
+      file from the &SCons; download page at
+      <ulink url="http://www.scons.org/download.php">http://www.scons.org/download.php</ulink>.
+      Then all you need to do is execute the file
+      (usually by clicking on its icon in Windows Explorer).
+      These will take you through a small
+      sequence of windows that will install
+      &SCons; on your system.
+
+      <!--
+      Things are a little more complicated
+      if you are using the Cygwin version of Python.
+      This is because Cygwin
+      tries to make a Windows system look more
+      POSIX-like (or UNIX-like or Linux-like, if you prefer)
+      by having the Cygwin utilities,
+      including Cygwin Python,
+      interpret file name arguments on the command line
+      using the forward-slash (<filename>/</filename>)
+      as the directory separator,
+      instead of the normal Windows behavior of the
+      backslash (<filename>\</filename>) as the directory separator.
+      -->
+
+      </para>
+
+      <!--
+
+      <section>
+      <title>Installing &SCons; on Windows Systems Without Cygwin Python</title>
+
+        <para>
+
+        XXX
+
+        </para>
+
+      </section>
+
+      <section>
+      <title>Installing &SCons; on Windows Systems With Cygwin Python</title>
+
+        <para>
+
+        XXX
+
+        </para>
+
+      </section>
+
+      -->
+
+      <!--
+
+      XXX - don't have the kinks worked out on how to
+      get these to display properly in all formats,
+      so comment them out for now.
+
+      <screenshot>
+      <mediaobject>
+        <imageobject>
+          <imagedata fileref="SCons-win32-install-1.jpg" format="jpg" align="center">
+        </imageobject>
+      </mediaobject>
+      </screenshot>
+
+      <screenshot>
+      <mediaobject>
+        <imageobject>
+          <imagedata fileref="SCons-win32-install-2.jpg" format="jpg" align="center">
+        </imageobject>
+      </mediaobject>
+      </screenshot>
+
+      <screenshot>
+      <mediaobject>
+        <imageobject>
+          <imagedata fileref="SCons-win32-install-3.jpg" format="jpg" align="center">
+        </imageobject>
+      </mediaobject>
+      </screenshot>
+
+      <screenshot>
+      <mediaobject>
+        <imageobject>
+          <imagedata fileref="SCons-win32-install-4.jpg" format="jpg" align="center">
+        </imageobject>
+      </mediaobject>
+      </screenshot>
+
+      -->
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Building and Installing &SCons; on Any System</title>
+
+    <para>
+
+    If a pre-built &SCons; package is not available for your system,
+    then you can still easily build and install &SCons; using the native
+    Python <filename>distutils</filename> package.
+
+    </para>
+
+    <para>
+
+    The first step is to download either the
+    <filename>scons-1.2.0.d20091224.tar.gz</filename>
+    or <filename>scons-1.2.0.d20091224.zip</filename>,
+    which are available from the SCons download page at
+    <ulink url="http://www.scons.org/download.html">http://www.scons.org/download.html</ulink>.
+
+    </para>
+
+    <para>
+
+    Unpack the archive you downloaded,
+    using a utility like <application>tar</application>
+    on Linux or UNIX,
+    or <application>WinZip</application> on Windows.
+    This will create a directory called
+    <filename>scons-1.2.0.d20091224</filename>,
+    usually in your local directory.
+    Then change your working directory to that directory
+    and install &SCons; by executing the following commands:
+
+    </para>
+
+    <screen>
+      # <userinput>cd scons-1.2.0.d20091224</userinput>
+      # <userinput>python setup.py install</userinput>
+    </screen>
+
+    <para>
+
+    This will build &SCons;,
+    install the &scons; script
+    in the default system scripts directory
+    (<filename>/usr/local/bin</filename> or
+    <filename>C:\Python25\Scripts</filename>),
+    and will install the &SCons; build engine
+    in an appropriate stand-alone library directory
+    (<filename>/usr/local/lib/scons</filename> or
+    <filename>C:\Python25\scons</filename>).
+    Because these are system directories,
+    you may need root (on Linux or UNIX) or Administrator (on Windows)
+    privileges to install &SCons; like this.
+
+    </para>
+
+    <!--
+
+    <section>
+    <title>Building and Installing &SCons; in the Standard Python Library Directories</title>
+
+      <para>
+
+      XXX
+
+      </para>
+
+    </section>
+
+    -->
+
+    <section>
+    <title>Building and Installing Multiple Versions of &SCons; Side-by-Side</title>
+
+      <para>
+
+      The &SCons; <filename>setup.py</filename> script
+      has some extensions that support
+      easy installation of multiple versions of &SCons;
+      in side-by-side locations.
+      This makes it easier to download and
+      experiment with different versions of &SCons;
+      before moving your official build process to a new version,
+      for example.
+
+      </para>
+
+      <para>
+
+      To install &SCons; in a version-specific location,
+      add the <option>--version-lib</option> option
+      when you call <filename>setup.py</filename>:
+
+      </para>
+
+      <screen>
+        # <userinput>python setup.py install --version-lib</userinput>
+      </screen>
+
+      <para>
+
+      This will install the &SCons; build engine
+      in the
+      <filename>/usr/lib/scons-1.2.0.d20091224</filename>
+      or
+      <filename>C:\Python25\scons-1.2.0.d20091224</filename>
+      directory, for example.
+
+      </para>
+
+      <para>
+
+      If you use the <option>--version-lib</option> option
+      the first time you install &SCons;,
+      you do not need to specify it each time you install
+      a new version.
+      The &SCons; <filename>setup.py</filename> script
+      will detect the version-specific directory name(s)
+      and assume you want to install all versions
+      in version-specific directories.
+      You can override that assumption in the future
+      by explicitly specifying the <option>--standalone-lib</option> option.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Installing &SCons; in Other Locations</title>
+
+      <para>
+
+      You can install &SCons; in locations other than
+      the default by specifying the <option>--prefix=</option> option:
+
+      </para>
+
+      <screen>
+        # <userinput>python setup.py install --prefix=/opt/scons</userinput>
+      </screen>
+
+      <para>
+
+      This would
+      install the <application>scons</application> script in
+      <filename>/opt/scons/bin</filename>
+      and the build engine in 
+      <filename>/opt/scons/lib/scons</filename>,
+
+      </para>
+
+      <para>
+
+      Note that you can specify both the <option>--prefix=</option>
+      and the <option>--version-lib</option> options
+      at the same type,
+      in which case <filename>setup.py</filename>
+      will install the build engine
+      in a version-specific directory
+      relative to the specified prefix.
+      Adding <option>--version-lib</option> to the
+      above example would install the build engine in
+      <filename>/opt/scons/lib/scons-1.2.0.d20091224</filename>.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Building and Installing &SCons; Without Administrative Privileges</title>
+
+      <para>
+
+      If you don't have the right privileges to install &SCons;
+      in a system location,
+      simply use the <literal>--prefix=</literal> option
+      to install it in a location of your choosing.
+      For example,
+      to install &SCons; in appropriate locations
+      relative to the user's <literal>$HOME</literal> directory,
+      the &scons; script in
+      <filename>$HOME/bin</filename>
+      and the build engine in 
+      <filename>$HOME/lib/scons</filename>,
+      simply type:
+
+      </para>
+
+      <screen>
+        $ <userinput>python setup.py install --prefix=$HOME</userinput>
+      </screen>
+
+      <para>
+
+      You may, of course, specify any other location you prefer,
+      and may use the <option>--version-lib</option> option
+      if you would like to install version-specific directories
+      relative to the specified prefix.
+
+      </para>
+
+      <para>
+
+      This can also be used to experiment with a newer
+      version of &SCons; than the one installed
+      in your system locations.
+      Of course, the location in which you install the
+      newer version of the &scons; script
+      (<filename>$HOME/bin</filename> in the above example)
+      must be configured in your &PATH; variable
+      before the directory containing
+      the system-installed version
+      of the &scons; script.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Python Basics</title>
+
+    <para>
+
+    This section will provide a brief overview of
+    the Python programming language.
+    Skip this section if you are already familiar with Python
+    (or you're really intent on diving into &SCons;
+    and just picking up things as you go).
+
+    </para>
+
+    <para>
+
+    Python has a lot of good
+    documentation freely available on-line
+    to help you get started.
+    The standard tutorial is available at XXX.
+
+
+    </para>
+
+    <para>
+
+    Python is very easy to pick up.
+
+    </para>
+
+    <para>
+
+    Python variables must be assigned to before they can be referenced.
+
+    </para>
+
+    <para>
+
+    Assignment is like most programming languages:
+
+    x = 1 + 2
+    z = 3 * x
+
+    </para>
+
+    <para>
+
+    Function calls look like most language function calls:
+
+    a = f(g)
+
+    </para>
+
+    <para>
+
+    Define functions like so:
+
+        def func(arg1, arg2):
+            return arg1 * arg 2
+
+    The number of parameters
+
+    </para>
+
+    <para>
+
+    Strings can be enclosed in single quotes or double quotes,
+    backslashes are used to escape characters,
+    triple-quote syntax lets you include quotes and newlines,
+    raw strings begin with 'r'.
+
+    </para>
+
+    <para>
+
+    Lists are enclosed in square brackets,
+    list items are separated by commas.
+    List references use square brackets and integer index values,
+    slice notation lets you select, delete or replace a range.
+
+    </para>
+
+    <para>
+
+    Dictionaries (hashes) are enclosed in curly brackets,
+    : separates keys from values,
+    , separates items.
+    Dictionary values are referenced using square brackets.
+
+    </para>
+
+    <para>
+
+    Access class attributes (including methods) using a '.'.
+
+    </para>
+
+    <para>
+
+    if: statements look like
+
+    elif: statements look like
+
+    else: statements look like
+
+    </para>
+
+    <para>
+
+    for: statements look like
+
+    while: statements look like
+
+    break statements look like
+    
+    continue statements look like
+
+    </para>
+
+    <para>
+
+    pass
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/builders-built-in.in b/doc/user/builders-built-in.in
new file mode 100644
index 0000000..245cb8c
--- /dev/null
+++ b/doc/user/builders-built-in.in
@@ -0,0 +1,963 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  &SCons; provides the ability to build a lot of different
+  types of files right "out of the box."
+  So far, we've been using &SCons;' ability to build
+  programs, objects and libraries to
+  illustrate much of the underlying functionality of &SCons;
+  This section will describe all of the different
+  types of files that you can build with &SCons;,
+  and the built-in &Builder; objects used to build them.
+  By default, all of the  &Builder; objects in this section
+  can be built either with or without an explicit
+  construction environment.
+
+  </para>
+
+  <section>
+  <title>Programs:  the &Program; Builder</title>
+
+    <para>
+
+    As we've seen, the &b-link-Program; Builder
+    is used to build an executable program.
+    The &source; argument is one or more
+    source-code files or object files,
+    and the &target; argument is the
+    name of the executable program name to be created.
+    For example:
+
+    </para>
+
+    <programlisting>
+      Program('prog', 'file1.o')
+    </programlisting>
+
+    <para>
+
+    Will create the &prog;
+    executable on a POSIX system,
+    the &prog_exe; executable on a Windows system.
+
+    </para>
+
+    <para>
+
+    The target file's prefix and suffix may be omitted,
+    and the values from the
+    &cv-link-PROGPREFIX;
+    and
+    &cv-link-PROGSUFFIX;
+    construction variables
+    will be appended appropriately.
+    For example:
+
+    </para>
+
+    <programlisting>
+      env = Environment(PROGPREFIX='my', PROGSUFFIX='.xxx')
+      env.Program('prog', ['file1.o', 'file2.o'])
+    </programlisting>
+
+    <para>
+
+    Will create a program named
+    <filename>myprog.xxx</filename>
+    regardless of the system on which it is run.
+
+    </para>
+
+    <para>
+
+    If you omit the &target;,
+    the base of the first input
+    file name specified
+    becomes the base of the target
+    program created.
+    For example:
+
+    </para>
+
+    <programlisting>
+      Program(['hello.c', 'goodbye.c'])
+    </programlisting>
+
+    <para>
+
+    Will create the &hello;
+    executable on a POSIX system,
+    the &hello_exe; executable on a Windows system.
+
+    </para>
+
+    <para>
+
+    Two construction variables control what libraries
+    will be linked with the resulting program.
+    The &cv-link-LIBS; variable is a list of the names of
+    libraries that will be linked into any programs,
+    and the &cv-link-LIBPATH; variables is a list of
+    directories that will be searched for
+    the specified libraries.
+    &SCons; will construct the right command-line
+    options for the running system.
+    For example:
+
+    </para>
+
+    <scons_example name="libs">
+      <file name="SConstruct" printme="1">
+      env = Environment(LIBS = ['foo1', 'foo2'],
+                        LIBPATH = ['/usr/dir1', 'dir2'])
+      env.Program(['hello.c', 'goodbye.c'])
+      </file>
+      <file name="hello.c">
+      int hello() { printf("Hello, world!\n"); }
+      </file>
+      <file name="goodbye.c">
+      int goodbye() { printf("Goodbye, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Will execute as follows on a POSIX system:
+
+    </para>
+
+    <scons_output example="libs" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    And execute as follows on a Windows system:
+
+    </para>
+
+    <scons_output example="libs" os="win32">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The &cv-LIBS; construction variable
+    is turned into command line options
+    by appending the &cv-link-LIBLINKPREFIX; and &cv-link-LIBLINKSUFFIX;
+    construction variables to the beginning and end,
+    respectively, of each specified library.
+
+    </para>
+
+    <para>
+
+    The &cv-LIBPATH; construction variable
+    is turned into command line options
+    by appending the &cv-link-LIBDIRPREFIX; and &cv-link-LIBDIRSUFFIX;
+    construction variables to the beginning and end,
+    respectively, of each specified library.
+
+    </para>
+
+    <para>
+
+    Other relevant construction variables
+    include those used by the &b-link-Object;
+    builders to affect how the
+    source files specified as input to the &t-Program;
+    builders are turned into object files;
+    see the next section.
+
+    </para>
+
+    <para>
+
+    The command line used to control how a program is linked
+    is specified by the &cv-link-LINKCOM; construction variable.
+    By default, it uses the
+    &cv-link-LINK; construction variable
+    and the &cv-link-LINKFLAGS; construction variable.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Object-File Builders</title>
+
+    <para>
+
+    &SCons; provides separate Builder objects
+    to create static and shared object files.
+    The distinction becomes especially important when
+    archiving object files into different types of libraries.
+
+    </para>
+
+    <section>
+    <title>The &StaticObject; Builder</title>
+
+      <para>
+
+      The &b-link-StaticObject; Builder
+      is used to build an object file
+      suitable for static linking into a program,
+      or for inclusion in a static library.
+      The &source; argument is a single source-code file,
+      and the &target; argument is the
+      name of the static object file to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        StaticObject('file', 'file.c')
+      </programlisting>
+
+      <para>
+
+      Will create the &file_o;
+      object file on a POSIX system,
+      the &file_obj; executable on a Windows system.
+
+      </para>
+
+      <para>
+
+      The target file's prefix and suffix may be omitted,
+      and the values from the
+      &cv-link-OBJPREFIX;
+      and
+      &cv-link-OBJSUFFIX;
+      construction variables
+      will be appended appropriately.
+      For example:
+
+      </para>
+
+      <programlisting>
+        env = Environment(OBJPREFIX='my', OBJSUFFIX='.xxx')
+        env.StaticObject('file', 'file.c')
+      </programlisting>
+
+      <para>
+
+      Will create an object file named
+      <filename>myfile.xxx</filename>
+      regardless of the system on which it is run.
+
+      </para>
+
+      <para>
+
+      If you omit the &target;,
+      the base of the first input
+      file name specified
+      beomces the base of the name
+      of the static object file to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        StaticObject('file.c')
+      </programlisting>
+
+      <para>
+
+      Will create the &file_o;
+      executable on a POSIX system,
+      the &file_obj; executable on a Windows system.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &SharedObject; Builder</title>
+
+      <para>
+
+      The &b-link-SharedObject; Builder
+      is used to build an object file
+      suitable for shared linking into a program,
+      or for inclusion in a shared library.
+      The &source; argument is a single source-code file,
+      and the &target; argument is the
+      name of the shared object file to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        SharedObject('file', 'file.c')
+      </programlisting>
+
+      <para>
+
+      Will create the &file_o;
+      object file on a POSIX system,
+      the &file_obj; executable on a Windows system.
+
+      </para>
+
+      <para>
+
+      The target file's prefix and suffix may be omitted,
+      and the values from the
+      &cv-link-SHOBJPREFIX;
+      and
+      &cv-link-SHOBJSUFFIX;
+      construction variables
+      will be appended appropriately.
+      For example:
+
+      </para>
+
+      <programlisting>
+        env = Environment(SHOBJPREFIX='my', SHOBJSUFFIX='.xxx')
+        env.SharedObject('file', 'file.c')
+      </programlisting>
+
+      <para>
+
+      Will create an object file named
+      <filename>myfile.xxx</filename>
+      regardless of the system on which it is run.
+
+      </para>
+
+      <para>
+
+      If you omit the &target;,
+      the base of the first input
+      file name specified
+      becomes the base of the name
+      of the shared object file to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        SharedObject('file.c')
+      </programlisting>
+
+      <para>
+
+      Will create the &file_o;
+      executable on a POSIX system,
+      the &file_obj; executable on a Windows system.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &Object; Builder</title>
+
+      <para>
+
+      The &b-link-Object; Builder is a synonym for &b-link-StaticObject;
+      and is completely equivalent.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Library Builders</title>
+
+    <para>
+
+    &SCons; provides separate Builder objects
+    to create static and shared libraries.
+
+    </para>
+
+    <section>
+    <title>The &StaticLibrary; Builder</title>
+
+      <para>
+
+      The &b-link-StaticLibrary; Builder
+      is used to create a library
+      suitable for static linking into a program.
+      The &source; argument is one or more
+      source-code files or object files,
+      and the &target; argument is the
+      name of the static library to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        StaticLibrary('foo', ['file1.c', 'file2.c'])
+      </programlisting>
+
+      <para>
+
+      The target file's prefix and suffix may be omitted,
+      and the values from the
+      &cv-link-LIBPREFIX;
+      and
+      &cv-link-LIBSUFFIX;
+      construction variables
+      will be appended appropriately.
+      For example:
+
+      </para>
+
+      <programlisting>
+        env = Environment(LIBPREFIX='my', LIBSUFFIX='.xxx')
+        env.StaticLibrary('lib', ['file1.o', 'file2.o'])
+      </programlisting>
+
+      <para>
+
+      Will create an object file named
+      <filename>mylib.xxx</filename>
+      regardless of the system on which it is run.
+
+      </para>
+
+      <programlisting>
+        StaticLibrary('foo', ['file1.c', 'file2.c'])
+      </programlisting>
+
+      <para>
+
+      If you omit the &target;,
+      the base of the first input
+      file name specified
+      becomes the base of the name of the static object file to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        StaticLibrary(['file.c', 'another.c'])
+      </programlisting>
+
+      <para>
+
+      Will create the &libfile_a;
+      library on a POSIX system,
+      the &file_lib; library on a Windows system.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &SharedLibrary; Builder</title>
+
+      <para>
+
+      The &b-link-SharedLibrary; Builder
+      is used to create a shared library
+      suitable for linking with a program.
+      The &source; argument is one or more
+      source-code files or object files,
+      and the &target; argument is the
+      name of the shared library to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        SharedLibrary('foo', ['file1.c', 'file2.c'])
+      </programlisting>
+
+      <para>
+
+      The target file's prefix and suffix may be omitted,
+      and the values from the
+      &cv-link-SHLIBPREFIX;
+      and
+      &cv-link-SHLIBSUFFIX;
+      construction variables
+      will be appended appropriately.
+      For example:
+
+      </para>
+
+      <programlisting>
+        env = Environment(SHLIBPREFIX='my', SHLIBSUFFIX='.xxx')
+        env.SharedLibrary('shared', ['file1.o', 'file2.o'])
+      </programlisting>
+
+      <para>
+
+      Will create an object file named
+      <filename>myshared.xxx</filename>
+      regardless of the system on which it is run.
+
+      </para>
+
+      <programlisting>
+        SharedLibrary('foo', ['file1.c', 'file2.c'])
+      </programlisting>
+
+      <para>
+
+      If you omit the &target;,
+      the base of the first input
+      file name specified
+      becomes the base of the name of the shared library to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        SharedLibrary(['file.c', 'another.c'])
+      </programlisting>
+
+      <para>
+
+      Will create the &libfile_so;
+      library on a POSIX system,
+      the &file_dll; library on a Windows system.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &Library; Builder</title>
+
+      <para>
+
+      The &b-link-Library; Builder is a synonym for &b-link-StaticLibrary;
+      and is completely equivalent.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Pre-Compiled Headers:  the &PCH; Builder</title>
+
+    <para>
+
+    XXX PCH()
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Microsoft Visual C++ Resource Files: the &RES; Builder</title>
+
+    <para>
+
+    XXX RES()
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Source Files</title>
+
+    <para>
+
+    By default
+    &SCons; supports two Builder objects
+    that know how to build source files
+    from other input files.
+    These are typically invoked "internally"
+    to turn files that need preprocessing into other source files.
+
+    </para>
+
+    <section>
+    <title>The &CFile; Builder</title>
+
+      <para>
+
+      XXX CFile()
+
+      </para>
+
+      <programlisting>
+        XXX CFile() programlisting
+      </programlisting>
+
+      <screen>
+        XXX CFile() screen
+      </screen>
+
+    </section>
+
+    <section>
+    <title>The &CXXFile; Builder</title>
+
+      <para>
+
+      XXX CXXFILE()
+
+      </para>
+
+      <programlisting>
+        XXX CXXFILE() programlisting
+      </programlisting>
+
+      <screen>
+        XXX CXXFILE() screen
+      </screen>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Documents</title>
+
+    <para>
+
+    &SCons; provides a number of Builder objects
+    for creating different types of documents.
+
+    </para>
+
+    <section>
+    <title>The &DVI; Builder</title>
+
+      <para>
+
+      XXX DVI() para
+
+      </para>
+
+      <programlisting>
+        XXX DVI() programlisting
+      </programlisting>
+
+      <screen>
+        XXX DVI() screen
+      </screen>
+
+    </section>
+
+    <section>
+    <title>The &PDF; Builder</title>
+
+      <para>
+
+      XXX PDF() para
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &PostScript; Builder</title>
+
+      <para>
+
+      XXX PostScript() para
+
+      </para>
+
+      <programlisting>
+        XXX PostScript() programlisting
+      </programlisting>
+
+      <screen>
+        XXX PostScript() screen
+      </screen>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Archives</title>
+
+    <para>
+
+    &SCons; provides Builder objects
+    for creating two different types of archive files.
+
+    </para>
+
+    <section>
+    <title>The &Tar; Builder</title>
+
+      <para>
+
+      The &b-link-Tar; Builder object uses the &tar;
+      utility to create archives of files
+      and/or directory trees:
+
+      </para>
+
+      <scons_example name="ex1">
+        <file name="SConstruct" printme="1">
+        env = Environment()
+        env.Tar('out1.tar', ['file1', 'file2'])
+        env.Tar('out2', 'directory')
+        </file>
+        <file name="file1">
+        file1
+        </file>
+        <file name="file2">
+        file2
+        </file>
+        <file name="directory/file3">
+        directory/file3
+        </file>
+      </scons_example>
+
+      <scons_output example="ex1" os="posix">
+        <scons_output_command>scons -Q .</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      One common requirement when creating a &tar; archive
+      is to create a compressed archive using the
+      <option>-z</option> option.
+      This is easily handled by specifying
+      the value of the &cv-link-TARFLAGS; variable
+      when you create the construction environment.
+      Note, however, that the <option>-c</option> used to
+      to instruct &tar; to create the archive
+      is part of the default value of &cv-TARFLAGS;,
+      so you need to set it both options:
+
+      </para>
+
+      <scons_example name="ex2">
+        <file name="SConstruct" printme="1">
+        env = Environment(TARFLAGS = '-c -z')
+        env.Tar('out.tar.gz', 'directory')
+        </file>
+        <file name="directory/file">
+        directory/file
+        </file>
+      </scons_example>
+
+      <scons_output example="ex2" os="posix">
+        <scons_output_command>scons -Q .</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      you may also wish to set the value of the
+      &cv-link-TARSUFFIX; construction variable
+      to your desired suffix for compress &tar; archives,
+      so that &SCons; can append it to the target file name
+      without your having to specify it explicitly:
+
+      </para>
+
+      <scons_example name="ex3">
+        <file name="SConstruct" printme="1">
+        env = Environment(TARFLAGS = '-c -z',
+                          TARSUFFIX = '.tgz')
+        env.Tar('out', 'directory')
+        </file>
+        <file name="directory/file">
+        directory/file
+        </file>
+      </scons_example>
+
+      <scons_output example="ex3" os="posix">
+        <scons_output_command>scons -Q .</scons_output_command>
+      </scons_output>
+
+    </section>
+
+    <section>
+    <title>The &Zip; Builder</title>
+
+      <para>
+
+      The &b-link-Zip; Builder object creates archives of files
+      and/or directory trees in the ZIP file format.
+      Python versions 1.6 or later
+      contain an internal &zipfile; module
+      that &SCons; will use.
+      In this case, given the following
+      &SConstruct; file:
+
+      </para>
+
+      <scons_example name="ex4">
+        <file name="SConstruct" printme="1">
+        env = Environment()
+        env.Zip('out', ['file1', 'file2'])
+        </file>
+        <file name="file1">
+        file1
+        </file>
+        <file name="file2">
+        file2
+        </file>
+      </scons_example>
+
+      <para>
+
+      Your output will reflect the fact
+      that an internal Python function
+      is being used to create the output ZIP archive:
+
+      </para>
+
+      <scons_output example="ex4" os="posix">
+        <scons_output_command>scons -Q .</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      If you're using Python version 1.5.2 to run &SCons;,
+      then &SCons; will try to use an external
+      &zip; program as follows:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q .</userinput>
+        zip /home/my/project/zip.out file1 file2
+      </screen>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Java</title>
+
+    <para>
+
+    &SCons; provides Builder objects
+    for creating various types of Java output files.
+
+    </para>
+
+    <section>
+    <title>Building Class Files:  the &Java; Builder</title>
+
+      <para>
+
+      The &b-link-Java; builder takes one or more input
+      <filename>.java</filename> files
+      and turns them into one or more
+      <filename>.class</filename> files
+      Unlike most builders, however,
+      the &Java; builder takes
+      target and source <emphasis>directories</emphasis>,
+      not files, as input.
+
+      </para>
+
+      <programlisting>
+        env = Environment()
+        env.Java(target = 'classes', source = 'src')
+      </programlisting>
+
+      <para>
+
+      The &Java; builder will then
+      search the specified source directory
+      tree for all <filename>.java</filename> files,
+      and pass any out-of-date
+
+      </para>
+
+      <screen>
+        XXX Java() screen
+      </screen>
+
+    </section>
+
+    <section>
+    <title>The &Jar; Builder</title>
+
+      <para>
+
+      XXX The &Jar; builder object
+
+      </para>
+
+      <programlisting>
+        env = Environment()
+        env.Java(target = 'classes', source = 'src')
+        env.Jar(target = '', source = 'classes')
+      </programlisting>
+
+      <screen>
+        XXX Jar() screen
+      </screen>
+
+    </section>
+
+    <section>
+    <title>Building C header and stub files:  the &JavaH; Builder</title>
+
+      <para>
+
+      XXX JavaH() para
+
+      </para>
+
+      <programlisting>
+        XXX JavaH() programlisting
+      </programlisting>
+
+      <screen>
+        XXX JavaH() screen
+      </screen>
+
+    </section>
+
+    <section>
+    <title>Building RMI stub and skeleton class files:  the &RMIC; Builder</title>
+
+      <para>
+
+      XXX RMIC() para
+
+      </para>
+
+      <programlisting>
+        XXX RMIC() programlisting
+      </programlisting>
+
+      <screen>
+        XXX RMIC() screen
+      </screen>
+
+    </section>
+
+  </section>
diff --git a/doc/user/builders-built-in.xml b/doc/user/builders-built-in.xml
new file mode 100644
index 0000000..bee5b38
--- /dev/null
+++ b/doc/user/builders-built-in.xml
@@ -0,0 +1,949 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  &SCons; provides the ability to build a lot of different
+  types of files right "out of the box."
+  So far, we've been using &SCons;' ability to build
+  programs, objects and libraries to
+  illustrate much of the underlying functionality of &SCons;
+  This section will describe all of the different
+  types of files that you can build with &SCons;,
+  and the built-in &Builder; objects used to build them.
+  By default, all of the  &Builder; objects in this section
+  can be built either with or without an explicit
+  construction environment.
+
+  </para>
+
+  <section>
+  <title>Programs:  the &Program; Builder</title>
+
+    <para>
+
+    As we've seen, the &b-link-Program; Builder
+    is used to build an executable program.
+    The &source; argument is one or more
+    source-code files or object files,
+    and the &target; argument is the
+    name of the executable program name to be created.
+    For example:
+
+    </para>
+
+    <programlisting>
+      Program('prog', 'file1.o')
+    </programlisting>
+
+    <para>
+
+    Will create the &prog;
+    executable on a POSIX system,
+    the &prog_exe; executable on a Windows system.
+
+    </para>
+
+    <para>
+
+    The target file's prefix and suffix may be omitted,
+    and the values from the
+    &cv-link-PROGPREFIX;
+    and
+    &cv-link-PROGSUFFIX;
+    construction variables
+    will be appended appropriately.
+    For example:
+
+    </para>
+
+    <programlisting>
+      env = Environment(PROGPREFIX='my', PROGSUFFIX='.xxx')
+      env.Program('prog', ['file1.o', 'file2.o'])
+    </programlisting>
+
+    <para>
+
+    Will create a program named
+    <filename>myprog.xxx</filename>
+    regardless of the system on which it is run.
+
+    </para>
+
+    <para>
+
+    If you omit the &target;,
+    the base of the first input
+    file name specified
+    becomes the base of the target
+    program created.
+    For example:
+
+    </para>
+
+    <programlisting>
+      Program(['hello.c', 'goodbye.c'])
+    </programlisting>
+
+    <para>
+
+    Will create the &hello;
+    executable on a POSIX system,
+    the &hello_exe; executable on a Windows system.
+
+    </para>
+
+    <para>
+
+    Two construction variables control what libraries
+    will be linked with the resulting program.
+    The &cv-link-LIBS; variable is a list of the names of
+    libraries that will be linked into any programs,
+    and the &cv-link-LIBPATH; variables is a list of
+    directories that will be searched for
+    the specified libraries.
+    &SCons; will construct the right command-line
+    options for the running system.
+    For example:
+
+    </para>
+
+    <programlisting>
+      env = Environment(LIBS = ['foo1', 'foo2'],
+                        LIBPATH = ['/usr/dir1', 'dir2'])
+      env.Program(['hello.c', 'goodbye.c'])
+    </programlisting>
+
+    <para>
+
+    Will execute as follows on a POSIX system:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o goodbye.o -c goodbye.c
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o goodbye.o -L/usr/dir1 -Ldir2 -lfoo1 -lfoo2
+    </screen>
+
+    <para>
+
+    And execute as follows on a Windows system:
+
+    </para>
+
+    <screen>
+      C:\><userinput>scons -Q</userinput>
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      cl /Fogoodbye.obj /c goodbye.c /nologo
+      cl /Fohello.obj /c hello.c /nologo
+      link /nologo /OUT:hello.exe /LIBPATH:\usr\dir1 /LIBPATH:dir2 foo1.lib foo2.lib hello.obj goodbye.obj
+    </screen>
+
+    <para>
+
+    The &cv-LIBS; construction variable
+    is turned into command line options
+    by appending the &cv-link-LIBLINKPREFIX; and &cv-link-LIBLINKSUFFIX;
+    construction variables to the beginning and end,
+    respectively, of each specified library.
+
+    </para>
+
+    <para>
+
+    The &cv-LIBPATH; construction variable
+    is turned into command line options
+    by appending the &cv-link-LIBDIRPREFIX; and &cv-link-LIBDIRSUFFIX;
+    construction variables to the beginning and end,
+    respectively, of each specified library.
+
+    </para>
+
+    <para>
+
+    Other relevant construction variables
+    include those used by the &b-link-Object;
+    builders to affect how the
+    source files specified as input to the &t-Program;
+    builders are turned into object files;
+    see the next section.
+
+    </para>
+
+    <para>
+
+    The command line used to control how a program is linked
+    is specified by the &cv-link-LINKCOM; construction variable.
+    By default, it uses the
+    &cv-link-LINK; construction variable
+    and the &cv-link-LINKFLAGS; construction variable.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Object-File Builders</title>
+
+    <para>
+
+    &SCons; provides separate Builder objects
+    to create static and shared object files.
+    The distinction becomes especially important when
+    archiving object files into different types of libraries.
+
+    </para>
+
+    <section>
+    <title>The &StaticObject; Builder</title>
+
+      <para>
+
+      The &b-link-StaticObject; Builder
+      is used to build an object file
+      suitable for static linking into a program,
+      or for inclusion in a static library.
+      The &source; argument is a single source-code file,
+      and the &target; argument is the
+      name of the static object file to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        StaticObject('file', 'file.c')
+      </programlisting>
+
+      <para>
+
+      Will create the &file_o;
+      object file on a POSIX system,
+      the &file_obj; executable on a Windows system.
+
+      </para>
+
+      <para>
+
+      The target file's prefix and suffix may be omitted,
+      and the values from the
+      &cv-link-OBJPREFIX;
+      and
+      &cv-link-OBJSUFFIX;
+      construction variables
+      will be appended appropriately.
+      For example:
+
+      </para>
+
+      <programlisting>
+        env = Environment(OBJPREFIX='my', OBJSUFFIX='.xxx')
+        env.StaticObject('file', 'file.c')
+      </programlisting>
+
+      <para>
+
+      Will create an object file named
+      <filename>myfile.xxx</filename>
+      regardless of the system on which it is run.
+
+      </para>
+
+      <para>
+
+      If you omit the &target;,
+      the base of the first input
+      file name specified
+      beomces the base of the name
+      of the static object file to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        StaticObject('file.c')
+      </programlisting>
+
+      <para>
+
+      Will create the &file_o;
+      executable on a POSIX system,
+      the &file_obj; executable on a Windows system.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &SharedObject; Builder</title>
+
+      <para>
+
+      The &b-link-SharedObject; Builder
+      is used to build an object file
+      suitable for shared linking into a program,
+      or for inclusion in a shared library.
+      The &source; argument is a single source-code file,
+      and the &target; argument is the
+      name of the shared object file to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        SharedObject('file', 'file.c')
+      </programlisting>
+
+      <para>
+
+      Will create the &file_o;
+      object file on a POSIX system,
+      the &file_obj; executable on a Windows system.
+
+      </para>
+
+      <para>
+
+      The target file's prefix and suffix may be omitted,
+      and the values from the
+      &cv-link-SHOBJPREFIX;
+      and
+      &cv-link-SHOBJSUFFIX;
+      construction variables
+      will be appended appropriately.
+      For example:
+
+      </para>
+
+      <programlisting>
+        env = Environment(SHOBJPREFIX='my', SHOBJSUFFIX='.xxx')
+        env.SharedObject('file', 'file.c')
+      </programlisting>
+
+      <para>
+
+      Will create an object file named
+      <filename>myfile.xxx</filename>
+      regardless of the system on which it is run.
+
+      </para>
+
+      <para>
+
+      If you omit the &target;,
+      the base of the first input
+      file name specified
+      becomes the base of the name
+      of the shared object file to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        SharedObject('file.c')
+      </programlisting>
+
+      <para>
+
+      Will create the &file_o;
+      executable on a POSIX system,
+      the &file_obj; executable on a Windows system.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &Object; Builder</title>
+
+      <para>
+
+      The &b-link-Object; Builder is a synonym for &b-link-StaticObject;
+      and is completely equivalent.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Library Builders</title>
+
+    <para>
+
+    &SCons; provides separate Builder objects
+    to create static and shared libraries.
+
+    </para>
+
+    <section>
+    <title>The &StaticLibrary; Builder</title>
+
+      <para>
+
+      The &b-link-StaticLibrary; Builder
+      is used to create a library
+      suitable for static linking into a program.
+      The &source; argument is one or more
+      source-code files or object files,
+      and the &target; argument is the
+      name of the static library to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        StaticLibrary('foo', ['file1.c', 'file2.c'])
+      </programlisting>
+
+      <para>
+
+      The target file's prefix and suffix may be omitted,
+      and the values from the
+      &cv-link-LIBPREFIX;
+      and
+      &cv-link-LIBSUFFIX;
+      construction variables
+      will be appended appropriately.
+      For example:
+
+      </para>
+
+      <programlisting>
+        env = Environment(LIBPREFIX='my', LIBSUFFIX='.xxx')
+        env.StaticLibrary('lib', ['file1.o', 'file2.o'])
+      </programlisting>
+
+      <para>
+
+      Will create an object file named
+      <filename>mylib.xxx</filename>
+      regardless of the system on which it is run.
+
+      </para>
+
+      <programlisting>
+        StaticLibrary('foo', ['file1.c', 'file2.c'])
+      </programlisting>
+
+      <para>
+
+      If you omit the &target;,
+      the base of the first input
+      file name specified
+      becomes the base of the name of the static object file to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        StaticLibrary(['file.c', 'another.c'])
+      </programlisting>
+
+      <para>
+
+      Will create the &libfile_a;
+      library on a POSIX system,
+      the &file_lib; library on a Windows system.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &SharedLibrary; Builder</title>
+
+      <para>
+
+      The &b-link-SharedLibrary; Builder
+      is used to create a shared library
+      suitable for linking with a program.
+      The &source; argument is one or more
+      source-code files or object files,
+      and the &target; argument is the
+      name of the shared library to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        SharedLibrary('foo', ['file1.c', 'file2.c'])
+      </programlisting>
+
+      <para>
+
+      The target file's prefix and suffix may be omitted,
+      and the values from the
+      &cv-link-SHLIBPREFIX;
+      and
+      &cv-link-SHLIBSUFFIX;
+      construction variables
+      will be appended appropriately.
+      For example:
+
+      </para>
+
+      <programlisting>
+        env = Environment(SHLIBPREFIX='my', SHLIBSUFFIX='.xxx')
+        env.SharedLibrary('shared', ['file1.o', 'file2.o'])
+      </programlisting>
+
+      <para>
+
+      Will create an object file named
+      <filename>myshared.xxx</filename>
+      regardless of the system on which it is run.
+
+      </para>
+
+      <programlisting>
+        SharedLibrary('foo', ['file1.c', 'file2.c'])
+      </programlisting>
+
+      <para>
+
+      If you omit the &target;,
+      the base of the first input
+      file name specified
+      becomes the base of the name of the shared library to be created.
+      For example:
+
+      </para>
+
+      <programlisting>
+        SharedLibrary(['file.c', 'another.c'])
+      </programlisting>
+
+      <para>
+
+      Will create the &libfile_so;
+      library on a POSIX system,
+      the &file_dll; library on a Windows system.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &Library; Builder</title>
+
+      <para>
+
+      The &b-link-Library; Builder is a synonym for &b-link-StaticLibrary;
+      and is completely equivalent.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Pre-Compiled Headers:  the &PCH; Builder</title>
+
+    <para>
+
+    XXX PCH()
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Microsoft Visual C++ Resource Files: the &RES; Builder</title>
+
+    <para>
+
+    XXX RES()
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Source Files</title>
+
+    <para>
+
+    By default
+    &SCons; supports two Builder objects
+    that know how to build source files
+    from other input files.
+    These are typically invoked "internally"
+    to turn files that need preprocessing into other source files.
+
+    </para>
+
+    <section>
+    <title>The &CFile; Builder</title>
+
+      <para>
+
+      XXX CFile()
+
+      </para>
+
+      <programlisting>
+        XXX CFile() programlisting
+      </programlisting>
+
+      <screen>
+        XXX CFile() screen
+      </screen>
+
+    </section>
+
+    <section>
+    <title>The &CXXFile; Builder</title>
+
+      <para>
+
+      XXX CXXFILE()
+
+      </para>
+
+      <programlisting>
+        XXX CXXFILE() programlisting
+      </programlisting>
+
+      <screen>
+        XXX CXXFILE() screen
+      </screen>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Documents</title>
+
+    <para>
+
+    &SCons; provides a number of Builder objects
+    for creating different types of documents.
+
+    </para>
+
+    <section>
+    <title>The &DVI; Builder</title>
+
+      <para>
+
+      XXX DVI() para
+
+      </para>
+
+      <programlisting>
+        XXX DVI() programlisting
+      </programlisting>
+
+      <screen>
+        XXX DVI() screen
+      </screen>
+
+    </section>
+
+    <section>
+    <title>The &PDF; Builder</title>
+
+      <para>
+
+      XXX PDF() para
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &PostScript; Builder</title>
+
+      <para>
+
+      XXX PostScript() para
+
+      </para>
+
+      <programlisting>
+        XXX PostScript() programlisting
+      </programlisting>
+
+      <screen>
+        XXX PostScript() screen
+      </screen>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Archives</title>
+
+    <para>
+
+    &SCons; provides Builder objects
+    for creating two different types of archive files.
+
+    </para>
+
+    <section>
+    <title>The &Tar; Builder</title>
+
+      <para>
+
+      The &b-link-Tar; Builder object uses the &tar;
+      utility to create archives of files
+      and/or directory trees:
+
+      </para>
+
+      <programlisting>
+        env = Environment()
+        env.Tar('out1.tar', ['file1', 'file2'])
+        env.Tar('out2', 'directory')
+      </programlisting>
+
+      <screen>
+        % <userinput>scons -Q .</userinput>
+        tar -c -f out1.tar file1 file2
+        tar -c -f out2.tar directory
+      </screen>
+
+      <para>
+
+      One common requirement when creating a &tar; archive
+      is to create a compressed archive using the
+      <option>-z</option> option.
+      This is easily handled by specifying
+      the value of the &cv-link-TARFLAGS; variable
+      when you create the construction environment.
+      Note, however, that the <option>-c</option> used to
+      to instruct &tar; to create the archive
+      is part of the default value of &cv-TARFLAGS;,
+      so you need to set it both options:
+
+      </para>
+
+      <programlisting>
+        env = Environment(TARFLAGS = '-c -z')
+        env.Tar('out.tar.gz', 'directory')
+      </programlisting>
+
+      <screen>
+        % <userinput>scons -Q .</userinput>
+        tar -c -z -f out.tar.gz directory
+      </screen>
+
+      <para>
+
+      you may also wish to set the value of the
+      &cv-link-TARSUFFIX; construction variable
+      to your desired suffix for compress &tar; archives,
+      so that &SCons; can append it to the target file name
+      without your having to specify it explicitly:
+
+      </para>
+
+      <programlisting>
+        env = Environment(TARFLAGS = '-c -z',
+                          TARSUFFIX = '.tgz')
+        env.Tar('out', 'directory')
+      </programlisting>
+
+      <screen>
+        % <userinput>scons -Q .</userinput>
+        tar -c -z -f out.tgz directory
+      </screen>
+
+    </section>
+
+    <section>
+    <title>The &Zip; Builder</title>
+
+      <para>
+
+      The &b-link-Zip; Builder object creates archives of files
+      and/or directory trees in the ZIP file format.
+      Python versions 1.6 or later
+      contain an internal &zipfile; module
+      that &SCons; will use.
+      In this case, given the following
+      &SConstruct; file:
+
+      </para>
+
+      <programlisting>
+        env = Environment()
+        env.Zip('out', ['file1', 'file2'])
+      </programlisting>
+
+      <para>
+
+      Your output will reflect the fact
+      that an internal Python function
+      is being used to create the output ZIP archive:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q .</userinput>
+        zip(["out.zip"], ["file1", "file2"])
+      </screen>
+
+      <para>
+
+      If you're using Python version 1.5.2 to run &SCons;,
+      then &SCons; will try to use an external
+      &zip; program as follows:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q .</userinput>
+        zip /home/my/project/zip.out file1 file2
+      </screen>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Java</title>
+
+    <para>
+
+    &SCons; provides Builder objects
+    for creating various types of Java output files.
+
+    </para>
+
+    <section>
+    <title>Building Class Files:  the &Java; Builder</title>
+
+      <para>
+
+      The &b-link-Java; builder takes one or more input
+      <filename>.java</filename> files
+      and turns them into one or more
+      <filename>.class</filename> files
+      Unlike most builders, however,
+      the &Java; builder takes
+      target and source <emphasis>directories</emphasis>,
+      not files, as input.
+
+      </para>
+
+      <programlisting>
+        env = Environment()
+        env.Java(target = 'classes', source = 'src')
+      </programlisting>
+
+      <para>
+
+      The &Java; builder will then
+      search the specified source directory
+      tree for all <filename>.java</filename> files,
+      and pass any out-of-date
+
+      </para>
+
+      <screen>
+        XXX Java() screen
+      </screen>
+
+    </section>
+
+    <section>
+    <title>The &Jar; Builder</title>
+
+      <para>
+
+      XXX The &Jar; builder object
+
+      </para>
+
+      <programlisting>
+        env = Environment()
+        env.Java(target = 'classes', source = 'src')
+        env.Jar(target = '', source = 'classes')
+      </programlisting>
+
+      <screen>
+        XXX Jar() screen
+      </screen>
+
+    </section>
+
+    <section>
+    <title>Building C header and stub files:  the &JavaH; Builder</title>
+
+      <para>
+
+      XXX JavaH() para
+
+      </para>
+
+      <programlisting>
+        XXX JavaH() programlisting
+      </programlisting>
+
+      <screen>
+        XXX JavaH() screen
+      </screen>
+
+    </section>
+
+    <section>
+    <title>Building RMI stub and skeleton class files:  the &RMIC; Builder</title>
+
+      <para>
+
+      XXX RMIC() para
+
+      </para>
+
+      <programlisting>
+        XXX RMIC() programlisting
+      </programlisting>
+
+      <screen>
+        XXX RMIC() screen
+      </screen>
+
+    </section>
+
+  </section>
diff --git a/doc/user/builders-commands.in b/doc/user/builders-commands.in
new file mode 100644
index 0000000..687d12d
--- /dev/null
+++ b/doc/user/builders-commands.in
@@ -0,0 +1,156 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <!--
+
+  =head2 The C<Command> method
+
+
+  The C<Command> method is called as follows:
+
+    Command $env <target>, <inputs>, <build action>;
+
+  The target is made dependent upon the list of input files specified, and the
+  inputs must be built successfully or Cons will not attempt to build the
+  target.
+
+  To specify a command with multiple targets, you can specify a reference to a
+  list of targets. In Perl, a list reference can be created by enclosing a
+  list in square brackets. Hence the following command:
+
+    Command $env ['foo.h', 'foo.c'], 'foo.template', q(
+  	gen %1
+    );
+
+  could be used in a case where the command C<gen> creates two files, both
+  F<foo.h> and F<foo.c>.
+
+  -->
+
+  <para>
+
+  Creating a &Builder; and attaching it to a &consenv;
+  allows for a lot of flexibility when you
+  want to re-use actions
+  to build multiple files of the same type.
+  This can, however, be cumbersome
+  if you only need to execute one specific command
+  to build a single file (or group of files).
+  For these situations, &SCons; supports a
+  &Command; &Builder; that arranges
+  for a specific action to be executed
+  to build a specific file or files.
+  This looks a lot like the other builders
+  (like &b-link-Program;, &b-link-Object;, etc.),
+  but takes as an additional argument
+  the command to be executed to build the file:
+
+  </para>
+
+  <scons_example name="ex1">
+     <file name="SConstruct" printme="1">
+     env = Environment()
+     env.Command('foo.out', 'foo.in', "sed 's/x/y/' < $SOURCE > $TARGET")
+     </file>
+     <file name="foo.in">
+     foo.in
+     </file>
+  </scons_example>
+
+  <para>
+
+  When executed,
+  &SCons; runs the specified command,
+  substituting &cv-link-SOURCE; and &cv-link-TARGET;
+  as expected:
+
+  </para>
+
+  <scons_output example="ex1">
+    <scons_output_command>scons -Q</scons_output_command>
+  </scons_output>
+
+  <para>
+
+  This is often more convenient than
+  creating a &Builder; object
+  and adding it to the &cv-link-BUILDERS; variable
+  of a &consenv;
+
+  </para>
+
+  <para>
+
+  Note that the action you specify to the
+  &Command; &Builder; can be any legal &SCons; &Action;,
+  such as a Python function:
+
+  </para>
+
+  <scons_example name="ex2">
+     <file name="SConstruct" printme="1">
+     env = Environment()
+     def build(target, source, env):
+         # Whatever it takes to build
+         return None
+     env.Command('foo.out', 'foo.in', build)
+     </file>
+     <file name="foo.in">
+     foo.in
+     </file>
+  </scons_example>
+
+  <para>
+
+  Which executes as follows:
+
+  </para>
+
+  <scons_output example="ex2">
+    <scons_output_command>scons -Q</scons_output_command>
+  </scons_output>
+
+  <para>
+
+  Note that &cv-link-SOURCE; and &cv-link-TARGET; are expanded 
+  in the source and target as well as of SCons 1.1,
+  so you can write:
+
+  </para>
+
+  <scons_example name="ex3">
+     <file name="SConstruct" printme="1">
+     env.Command('${SOURCE.basename}.out', 'foo.in', build)
+     </file>
+  </scons_example>
+
+
+  <para>
+
+  which does the same thing as the previous example, but allows you
+  to avoid repeating yourself.
+
+  </para>
+
diff --git a/doc/user/builders-commands.xml b/doc/user/builders-commands.xml
new file mode 100644
index 0000000..111b1d2
--- /dev/null
+++ b/doc/user/builders-commands.xml
@@ -0,0 +1,146 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <!--
+
+  =head2 The C<Command> method
+
+
+  The C<Command> method is called as follows:
+
+    Command $env <target>, <inputs>, <build action>;
+
+  The target is made dependent upon the list of input files specified, and the
+  inputs must be built successfully or Cons will not attempt to build the
+  target.
+
+  To specify a command with multiple targets, you can specify a reference to a
+  list of targets. In Perl, a list reference can be created by enclosing a
+  list in square brackets. Hence the following command:
+
+    Command $env ['foo.h', 'foo.c'], 'foo.template', q(
+  	gen %1
+    );
+
+  could be used in a case where the command C<gen> creates two files, both
+  F<foo.h> and F<foo.c>.
+
+  -->
+
+  <para>
+
+  Creating a &Builder; and attaching it to a &consenv;
+  allows for a lot of flexibility when you
+  want to re-use actions
+  to build multiple files of the same type.
+  This can, however, be cumbersome
+  if you only need to execute one specific command
+  to build a single file (or group of files).
+  For these situations, &SCons; supports a
+  &Command; &Builder; that arranges
+  for a specific action to be executed
+  to build a specific file or files.
+  This looks a lot like the other builders
+  (like &b-link-Program;, &b-link-Object;, etc.),
+  but takes as an additional argument
+  the command to be executed to build the file:
+
+  </para>
+
+  <programlisting>
+     env = Environment()
+     env.Command('foo.out', 'foo.in', "sed 's/x/y/' &lt; $SOURCE &gt; $TARGET")
+  </programlisting>
+
+  <para>
+
+  When executed,
+  &SCons; runs the specified command,
+  substituting &cv-link-SOURCE; and &cv-link-TARGET;
+  as expected:
+
+  </para>
+
+  <screen>
+    % <userinput>scons -Q</userinput>
+    sed 's/x/y/' &lt; foo.in &gt; foo.out
+  </screen>
+
+  <para>
+
+  This is often more convenient than
+  creating a &Builder; object
+  and adding it to the &cv-link-BUILDERS; variable
+  of a &consenv;
+
+  </para>
+
+  <para>
+
+  Note that the action you specify to the
+  &Command; &Builder; can be any legal &SCons; &Action;,
+  such as a Python function:
+
+  </para>
+
+  <programlisting>
+     env = Environment()
+     def build(target, source, env):
+         # Whatever it takes to build
+         return None
+     env.Command('foo.out', 'foo.in', build)
+  </programlisting>
+
+  <para>
+
+  Which executes as follows:
+
+  </para>
+
+  <screen>
+    % <userinput>scons -Q</userinput>
+    build(["foo.out"], ["foo.in"])
+  </screen>
+
+  <para>
+
+  Note that &cv-link-SOURCE; and &cv-link-TARGET; are expanded 
+  in the source and target as well as of SCons 1.1,
+  so you can write:
+
+  </para>
+
+  <programlisting>
+     env.Command('${SOURCE.basename}.out', 'foo.in', build)
+  </programlisting>
+
+
+  <para>
+
+  which does the same thing as the previous example, but allows you
+  to avoid repeating yourself.
+
+  </para>
+
diff --git a/doc/user/builders-writing.in b/doc/user/builders-writing.in
new file mode 100644
index 0000000..4f54d99
--- /dev/null
+++ b/doc/user/builders-writing.in
@@ -0,0 +1,1087 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head2 Adding new methods
+
+For slightly more demanding changes, you may wish to add new methods to the
+C<cons> package. Here's an example of a very simple extension,
+C<InstallScript>, which installs a tcl script in a requested location, but
+edits the script first to reflect a platform-dependent path that needs to be
+installed in the script:
+
+  # cons::InstallScript - Create a platform dependent version of a shell
+  # script by replacing string ``#!your-path-here'' with platform specific
+  # path $BIN_DIR.
+
+  sub cons::InstallScript {
+	my ($env, $dst, $src) = @_;
+	Command $env $dst, $src, qq(
+		sed s+your-path-here+$BIN_DIR+ %< > %>
+		chmod oug+x %>
+	);
+  }
+
+Notice that this method is defined directly in the C<cons> package (by
+prefixing the name with C<cons::>). A change made in this manner will be
+globally visible to all environments, and could be called as in the
+following example:
+
+  InstallScript $env "$BIN/foo", "foo.tcl";
+
+For a small improvement in generality, the C<BINDIR> variable could be
+passed in as an argument or taken from the construction environment-,-as
+C<%BINDIR>.
+
+
+=head2 Overriding methods
+
+Instead of adding the method to the C<cons> name space, you could define a
+new package which inherits existing methods from the C<cons> package and
+overrides or adds others. This can be done using Perl's inheritance
+mechanisms.
+
+The following example defines a new package C<cons::switch> which
+overrides the standard C<Library> method. The overridden method builds
+linked library modules, rather than library archives. A new
+constructor is provided. Environments created with this constructor
+will have the new library method; others won't.
+
+  package cons::switch;
+  BEGIN {@ISA = 'cons'}
+
+  sub new {
+	shift;
+	bless new cons(@_);
+  }
+
+  sub Library {
+	my($env) = shift;
+	my($lib) = shift;
+	my(@objs) = Objects $env @_;
+	Command $env $lib, @objs, q(
+		%LD -r %LDFLAGS %< -o %>
+	);
+  }
+
+This functionality could be invoked as in the following example:
+
+  $env = new cons::switch(@overrides);
+  ...
+  Library $env 'lib.o', 'foo.c', 'bar.c';
+
+-->
+
+  <para>
+
+  Although &SCons; provides many useful methods
+  for building common software products:
+  programs, libraries, documents.
+  you frequently want to be
+  able to build some other type of file
+  not supported directly by &SCons;.
+  Fortunately, &SCons; makes it very easy
+  to define your own &Builder; objects
+  for any custom file types you want to build.
+  (In fact, the &SCons; interfaces for creating
+  &Builder; objects are flexible enough and easy enough to use
+  that all of the the &SCons; built-in &Builder; objects
+  are created the mechanisms described in this section.)
+
+  </para>
+
+  <section>
+  <title>Writing Builders That Execute External Commands</title>
+
+    <para>
+
+    The simplest &Builder; to create is
+    one that executes an external command.
+    For example, if we want to build
+    an output file by running the contents
+    of the input file through a command named
+    <literal>foobuild</literal>,
+    creating that &Builder; might look like:
+
+    </para>
+
+    <programlisting>
+       bld = Builder(action = 'foobuild < $SOURCE > $TARGET')
+    </programlisting>
+
+    <para>
+
+    All the above line does is create a free-standing
+    &Builder; object.
+    The next section will show us how to actually use it.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Attaching a Builder to a &ConsEnv;</title>
+
+    <para>
+
+    A &Builder; object isn't useful
+    until it's attached to a &consenv;
+    so that we can call it to arrange
+    for files to be built.
+    This is done through the &cv-link-BUILDERS;
+    &consvar; in an environment.
+    The &cv-BUILDERS; variable is a Python dictionary
+    that maps the names by which you want to call
+    various &Builder; objects to the objects themselves.
+    For example, if we want to call the
+    &Builder; we just defined by the name
+    <function>Foo</function>,
+    our &SConstruct; file might look like:
+
+    </para>
+
+    <scons_example name="ex1">
+       <file name="SConstruct">
+       bld = Builder(action = 'foobuild < $SOURCE > $TARGET')
+       env = Environment(BUILDERS = {'Foo' : bld})
+       import os
+       env['ENV']['PATH'] = env['ENV']['PATH'] + os.pathsep + os.getcwd()
+       env.Foo('file.foo', 'file.input')
+       </file>
+       <file name="file.input">
+       file.input
+       </file>
+       <file name="foobuild" chmod="0755">
+       cat
+       </file>
+    </scons_example>
+
+    <sconstruct>
+       bld = Builder(action = 'foobuild < $SOURCE > $TARGET')
+       env = Environment(BUILDERS = {'Foo' : bld})
+    </sconstruct>
+
+    <para>
+
+    With the &Builder; attached to our &consenv;
+    with the name <function>Foo</function>,
+    we can now actually call it like so:
+
+    </para>
+
+    <programlisting>
+       env.Foo('file.foo', 'file.input')
+    </programlisting>
+
+    <para>
+
+    Then when we run &SCons; it looks like:
+
+    </para>
+
+    <scons_output example="ex1">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Note, however, that the default &cv-BUILDERS;
+    variable in a &consenv;
+    comes with a default set of &Builder; objects
+    already defined:
+    &b-link-Program;, &b-link-Library;, etc.
+    And when we explicitly set the &cv-BUILDERS; variable
+    when we create the &consenv;,
+    the default &Builder;s are no longer part of
+    the environment:
+
+    </para>
+
+   <!--
+   The ToolSurrogate stuff that's used to capture output initializes
+   SCons.Defaults.ConstructionEnvironment with its own list of TOOLS.
+   In this next example, we want to show the user that when they
+   set the BUILDERS explicitly, the call to env.Program() generates
+   an AttributeError.  This won't happen with all of the default
+   ToolSurrogates in the default construction environment.  To make the
+   AttributeError show up, we have to overwite the default construction
+   environment's TOOLS variable so Program() builder doesn't show up.
+
+   We do this by executing a slightly different SConstruct file than the
+   one we print in the guide, with two extra statements at the front
+   that overwrite the TOOLS variable as described.  Note that we have
+   to jam those statements on to the first line to keep the line number
+   in the generated error consistent with what the user will see in the
+   User's Guide.
+   -->
+    <scons_example name="ex2">
+       <file name="SConstruct">
+       import SCons.Defaults; SCons.Defaults.ConstructionEnvironment['TOOLS'] = {}; bld = Builder(action = 'foobuild &lt; $SOURCE &gt; $TARGET')
+       env = Environment(BUILDERS = {'Foo' : bld})
+       env.Foo('file.foo', 'file.input')
+       env.Program('hello.c')
+       </file>
+       <file name="SConstruct.printme" printme="1">
+       bld = Builder(action = 'foobuild &lt; $SOURCE &gt; $TARGET')
+       env = Environment(BUILDERS = {'Foo' : bld})
+       env.Foo('file.foo', 'file.input')
+       env.Program('hello.c')
+       </file>
+       <file name="file.input">
+       file.input
+       </file>
+       <file name="hello.c">
+       hello.c
+       </file>
+    </scons_example>
+
+    <scons_output example="ex2">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    To be able to use both our own defined &Builder; objects
+    and the default &Builder; objects in the same &consenv;,
+    you can either add to the &cv-BUILDERS; variable
+    using the &Append; function:
+
+    </para>
+
+    <scons_example name="ex3">
+       <file name="SConstruct">
+       env = Environment()
+       import os
+       env['ENV']['PATH'] = env['ENV']['PATH'] + os.pathsep + os.getcwd()
+       bld = Builder(action = 'foobuild < $SOURCE > $TARGET')
+       env.Append(BUILDERS = {'Foo' : bld})
+       env.Foo('file.foo', 'file.input')
+       env.Program('hello.c')
+       </file>
+       <file name="file.input">
+       file.input
+       </file>
+       <file name="hello.c">
+       hello.c
+       </file>
+       <file name="foobuild" chmod="0755">
+       cat
+       </file>
+    </scons_example>
+
+    <sconstruct>
+       env = Environment()
+       bld = Builder(action = 'foobuild < $SOURCE > $TARGET')
+       env.Append(BUILDERS = {'Foo' : bld})
+       env.Foo('file.foo', 'file.input')
+       env.Program('hello.c')
+    </sconstruct>
+
+    <para>
+
+    Or you can explicitly set the appropriately-named
+    key in the &cv-BUILDERS; dictionary:
+
+    </para>
+
+    <sconstruct>
+       env = Environment()
+       bld = Builder(action = 'foobuild < $SOURCE > $TARGET')
+       env['BUILDERS']['Foo'] = bld
+       env.Foo('file.foo', 'file.input')
+       env.Program('hello.c')
+    </sconstruct>
+
+    <para>
+
+    Either way, the same &consenv;
+    can then use both the newly-defined
+    <function>Foo</function> &Builder;
+    and the default &b-link-Program; &Builder;:
+
+    </para>
+
+    <scons_output example="ex3">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Letting &SCons; Handle The File Suffixes</title>
+
+    <para>
+
+    By supplying additional information
+    when you create a &Builder;,
+    you can let &SCons; add appropriate file
+    suffixes to the target and/or the source file.
+    For example, rather than having to specify
+    explicitly that you want the <literal>Foo</literal>
+    &Builder; to build the <literal>file.foo</literal>
+    target file from the <literal>file.input</literal> source file,
+    you can give the <literal>.foo</literal>
+    and <literal>.input</literal> suffixes to the &Builder;,
+    making for more compact and readable calls to
+    the <literal>Foo</literal> &Builder;:
+
+    </para>
+
+    <scons_example name="ex4">
+       <file name="SConstruct">
+       bld = Builder(action = 'foobuild < $SOURCE > $TARGET',
+                     suffix = '.foo',
+                     src_suffix = '.input')
+       env = Environment(BUILDERS = {'Foo' : bld})
+       import os
+       env['ENV']['PATH'] = env['ENV']['PATH'] + os.pathsep + os.getcwd()
+       env.Foo('file1')
+       env.Foo('file2')
+       </file>
+       <file name="file1.input">
+       file1.input
+       </file>
+       <file name="file2.input">
+       file2.input
+       </file>
+       <file name="foobuild" chmod="0755">
+       cat
+       </file>
+    </scons_example>
+
+    <sconstruct>
+       bld = Builder(action = 'foobuild < $SOURCE > $TARGET',
+                     suffix = '.foo',
+                     src_suffix = '.input')
+       env = Environment(BUILDERS = {'Foo' : bld})
+       env.Foo('file1')
+       env.Foo('file2')
+    </sconstruct>
+
+    <scons_output example="ex4">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    You can also supply a <literal>prefix</literal> keyword argument
+    if it's appropriate to have &SCons; append a prefix
+    to the beginning of target file names.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Builders That Execute Python Functions</title>
+
+    <para>
+
+    In &SCons;, you don't have to call an external command
+    to build a file.
+    You can, instead, define a Python function
+    that a &Builder; object can invoke
+    to build your target file (or files).
+    Such a &buildfunc; definition looks like:
+
+    </para>
+
+    <programlisting>
+       def build_function(target, source, env):
+           # Code to build "target" from "source"
+           return None
+    </programlisting>
+
+    <para>
+
+    The arguments of a &buildfunc; are:
+
+    </para>
+
+    <variablelist>
+
+      <varlistentry>
+      <term>target</term>
+
+      <listitem>
+      <para>
+
+      A list of Node objects representing
+      the target or targets to be
+      built by this builder function.
+      The file names of these target(s)
+      may be extracted using the Python &str; function.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>source</term>
+
+      <listitem>
+      <para>
+
+      A list of Node objects representing
+      the sources to be
+      used by this builder function to build the targets.
+      The file names of these source(s)
+      may be extracted using the Python &str; function.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>env</term>
+
+      <listitem>
+      <para>
+
+      The &consenv; used for building the target(s).
+      The builder function may use any of the
+      environment's construction variables
+      in any way to affect how it builds the targets.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+    </variablelist>
+
+    <para>
+
+    The builder function must
+    return a <literal>0</literal> or <literal>None</literal> value
+    if the target(s) are built successfully.
+    The builder function
+    may raise an exception
+    or return any non-zero value
+    to indicate that the build is unsuccessful,
+
+    </para>
+
+    <para>
+
+    Once you've defined the Python function
+    that will build your target file,
+    defining a &Builder; object for it is as
+    simple as specifying the name of the function,
+    instead of an external command,
+    as the &Builder;'s
+    <literal>action</literal>
+    argument:
+
+    </para>
+
+    <scons_example name="ex5">
+       <file name="SConstruct" printme="1">
+       def build_function(target, source, env):
+           # Code to build "target" from "source"
+           return None
+       bld = Builder(action = build_function,
+                     suffix = '.foo',
+                     src_suffix = '.input')
+       env = Environment(BUILDERS = {'Foo' : bld})
+       env.Foo('file')
+       </file>
+       <file name="file.input">
+       file.input
+       </file>
+    </scons_example>
+
+    <para>
+
+    And notice that the output changes slightly,
+    reflecting the fact that a Python function,
+    not an external command,
+    is now called to build the target file:
+
+    </para>
+
+    <scons_output example="ex5">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Builders That Create Actions Using a &Generator;</title>
+
+    <para>
+
+    &SCons; Builder objects can create an action "on the fly"
+    by using a function called a &generator;.
+    This provides a great deal of flexibility to
+    construct just the right list of commands
+    to build your target.
+    A &generator; looks like:
+
+    </para>
+
+    <programlisting>
+       def generate_actions(source, target, env, for_signature):
+           return 'foobuild < %s > %s' % (target[0], source[0])
+    </programlisting>
+
+    <para>
+
+    The arguments of a &generator; are:
+
+    </para>
+
+    <variablelist>
+
+      <varlistentry>
+      <term>source</term>
+
+      <listitem>
+      <para>
+
+      A list of Node objects representing
+      the sources to be built
+      by the command or other action
+      generated by this function.
+      The file names of these source(s)
+      may be extracted using the Python &str; function.
+
+      </para>
+      </listitem>
+
+      </varlistentry>
+
+      <varlistentry>
+      <term>target</term>
+
+      <listitem>
+      <para>
+
+      A list of Node objects representing
+      the target or targets to be built
+      by the command or other action
+      generated by this function.
+      The file names of these target(s)
+      may be extracted using the Python &str; function.
+
+      </para>
+      </listitem>
+
+      </varlistentry>
+
+      <varlistentry>
+      <term>env</term>
+
+      <listitem>
+      <para>
+
+      The &consenv; used for building the target(s).
+      The generator may use any of the
+      environment's construction variables
+      in any way to determine what command
+      or other action to return.
+
+      </para>
+      </listitem>
+
+      </varlistentry>
+
+      <varlistentry>
+      <term>for_signature</term>
+
+      <listitem>
+      <para>
+
+      A flag that specifies whether the
+      generator is being called to contribute to a build signature,
+      as opposed to actually executing the command.
+
+      <!-- XXX NEED MORE HERE, describe generators use in signatures -->
+
+      </para>
+      </listitem>
+
+      </varlistentry>
+
+    </variablelist>
+
+    <para>
+
+    The &generator; must return a
+    command string or other action that will be used to
+    build the specified target(s) from the specified source(s).
+
+    </para>
+
+    <para>
+
+    Once you've defined a &generator;,
+    you create a &Builder; to use it
+    by specifying the generator keyword argument
+    instead of <literal>action</literal>.
+
+    </para>
+
+    <scons_example name="ex6">
+       <file name="SConstruct">
+       def generate_actions(source, target, env, for_signature):
+           return 'foobuild < %s > %s' % (source[0], target[0])
+       bld = Builder(generator = generate_actions,
+                     suffix = '.foo',
+                     src_suffix = '.input')
+       env = Environment(BUILDERS = {'Foo' : bld})
+       import os
+       env['ENV']['PATH'] = env['ENV']['PATH'] + os.pathsep + os.getcwd()
+       env.Foo('file')
+       </file>
+       <file name="file.input">
+       file.input
+       </file>
+       <file name="foobuild" chmod="0755">
+       cat
+       </file>
+    </scons_example>
+
+    <sconstruct>
+       def generate_actions(source, target, env, for_signature):
+           return 'foobuild < %s > %s' % (source[0], target[0])
+       bld = Builder(generator = generate_actions,
+                     suffix = '.foo',
+                     src_suffix = '.input')
+       env = Environment(BUILDERS = {'Foo' : bld})
+       env.Foo('file')
+    </sconstruct>
+
+    <scons_output example="ex6">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Note that it's illegal to specify both an
+    <literal>action</literal>
+    and a
+    <literal>generator</literal>
+    for a &Builder;.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Builders That Modify the Target or Source Lists Using an &Emitter;</title>
+
+    <para>
+
+    &SCons; supports the ability for a Builder to modify the
+    lists of target(s) from the specified source(s).
+    You do this by defining an &emitter; function
+    that takes as its arguments
+    the list of the targets passed to the builder,
+    the list of the sources passed to the builder,
+    and the construction environment.
+    The emitter function should return the modified
+    lists of targets that should be built
+    and sources from which the targets will be built.
+
+    </para>
+
+    <para>
+
+    For example, suppose you want to define a Builder
+    that always calls a <filename>foobuild</filename> program,
+    and you want to automatically add
+    a new target file named
+    <filename>new_target</filename>
+    and a new source file named
+    <filename>new_source</filename>
+    whenever it's called.
+    The &SConstruct; file might look like this:
+
+    </para>
+
+    <scons_example name="ex7">
+       <file name="SConstruct">
+       def modify_targets(target, source, env):
+           target.append('new_target')
+           source.append('new_source')
+           return target, source
+       bld = Builder(action = 'foobuild $TARGETS - $SOURCES',
+                     suffix = '.foo',
+                     src_suffix = '.input',
+                     emitter = modify_targets)
+       env = Environment(BUILDERS = {'Foo' : bld})
+       import os
+       env['ENV']['PATH'] = env['ENV']['PATH'] + os.pathsep + os.getcwd()
+       env.Foo('file')
+       </file>
+       <file name="file.input">
+       file.input
+       </file>
+       <file name="new_source">
+       new_source
+       </file>
+       <file name="foobuild" chmod="0755">
+       cat
+       </file>
+    </scons_example>
+
+    <sconstruct>
+       def modify_targets(target, source, env):
+           target.append('new_target')
+           source.append('new_source')
+           return target, source
+       bld = Builder(action = 'foobuild $TARGETS - $SOURCES',
+                     suffix = '.foo',
+                     src_suffix = '.input',
+                     emitter = modify_targets)
+       env = Environment(BUILDERS = {'Foo' : bld})
+       env.Foo('file')
+    </sconstruct>
+
+    <para>
+    
+    And would yield the following output:
+
+    </para>
+
+    <scons_output example="ex7">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    One very flexible thing that you can do is
+    use a construction variable to specify
+    different emitter functions for different
+    construction variable.
+    To do this, specify a string
+    containing a construction variable
+    expansion as the emitter when you call
+    the &Builder; function,
+    and set that construction variable to
+    the desired emitter function
+    in different construction environments:
+
+    </para>
+
+    <scons_example name="MY_EMITTER">
+
+      <file name="SConstruct" printme="1">
+        bld = Builder(action = 'my_command $SOURCES > $TARGET',
+                      suffix = '.foo',
+                      src_suffix = '.input',
+                      emitter = '$MY_EMITTER')
+        def modify1(target, source, env):
+            return target, source + ['modify1.in']
+        def modify2(target, source, env):
+            return target, source + ['modify2.in']
+        env1 = Environment(BUILDERS = {'Foo' : bld},
+                           MY_EMITTER = modify1)
+        env2 = Environment(BUILDERS = {'Foo' : bld},
+                           MY_EMITTER = modify2)
+        env1.Foo('file1')
+        env2.Foo('file2')
+        import os
+        env1['ENV']['PATH'] = env2['ENV']['PATH'] + os.pathsep + os.getcwd()
+        env2['ENV']['PATH'] = env2['ENV']['PATH'] + os.pathsep + os.getcwd()
+        </file>
+        <file name="file1.input">
+        file1.input
+        </file>
+        <file name="file2.input">
+        file2.input
+        </file>
+        <file name="modify1.in">
+        modify1.input
+        </file>
+        <file name="modify2.in">
+        modify2.input
+        </file>
+        <file name="my_command" chmod="0755">
+        cat
+        </file>
+      </file>
+
+    </scons_example>
+
+    <sconstruct>
+      bld = Builder(action = 'my_command $SOURCES > $TARGET',
+                    suffix = '.foo',
+                    src_suffix = '.input',
+                    emitter = '$MY_EMITTER')
+      def modify1(target, source, env):
+          return target, source + ['modify1.in']
+      def modify2(target, source, env):
+          return target, source + ['modify2.in']
+      env1 = Environment(BUILDERS = {'Foo' : bld},
+                         MY_EMITTER = modify1)
+      env2 = Environment(BUILDERS = {'Foo' : bld},
+                         MY_EMITTER = modify2)
+      env1.Foo('file1')
+      env2.Foo('file2')
+      </file>
+    </sconstruct>
+
+    <para>
+
+    In this example, the <filename>modify1.in</filename>
+    and <filename>modify2.in</filename> files
+    get added to the source lists
+    of the different commands:
+
+    </para>
+
+    <scons_output example="MY_EMITTER">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>target_factor=, source_factory=</title>
+
+  </section>
+
+  <section>
+  <title>target_scanner=, source_scanner=</title>
+
+  </section>
+
+  <section>
+  <title>multi=</title>
+
+  </section>
+
+  <section>
+  <title>single_source=</title>
+
+  </section>
+
+  <section>
+  <title>src_builder=</title>
+
+  </section>
+
+  <section>
+  <title>ensure_suffix=</title>
+
+  </section>
+
+  -->
+
+  <section>
+  <title>Where To Put Your Custom Builders and Tools</title>
+
+    <para>
+
+    The <filename>site_scons</filename> directory gives you a place to
+    put Python modules you can import into your SConscripts
+    (site_scons), add-on tools that can integrate into &SCons;
+    (site_scons/site_tools), and a site_scons/site_init.py file that
+    gets read before any &SConstruct; or &SConscript;, allowing you to
+    change &SCons;'s default behavior.
+
+    </para>
+
+    <para>
+
+    If you get a tool from somewhere (the &SCons; wiki or a third party,
+    for instance) and you'd like to use it in your project, the
+    <filename>site_scons</filename> dir is the simplest place to put it.
+    Tools come in two flavors; either a Python function that operates on
+    an &Environment; or a Python file containing two functions, exists()
+    and generate().
+
+    </para>
+
+    <para>
+
+    A single-function Tool can just be included in your
+    <filename>site_scons/site_init.py</filename> file where it will be
+    parsed and made available for use.  For instance, you could have a
+    <filename>site_scons/site_init.py</filename> file like this:
+
+    </para>
+
+    <scons_example name="site1">
+      <file name="site_scons/site_init.py" printme=1>
+        def TOOL_ADD_HEADER(env):
+           """A Tool to add a header from $HEADER to the source file"""
+           add_header = Builder(action=['echo "$HEADER" > $TARGET',
+                                        'cat $SOURCE >> $TARGET'])
+           env.Append(BUILDERS = {'AddHeader' : add_header})
+           env['HEADER'] = '' # set default value
+      </file>
+      <file name="SConstruct">
+        env=Environment(tools=['default', TOOL_ADD_HEADER], HEADER="=====")
+        env.AddHeader('tgt', 'src')
+      </file>
+      <file name="src">
+        hi there
+      </file>
+    </scons_example>
+
+    <para>
+
+    and a &SConstruct; like this:
+
+    </para>
+
+    <sconstruct>
+        # Use TOOL_ADD_HEADER from site_scons/site_init.py
+        env=Environment(tools=['default', TOOL_ADD_HEADER], HEADER="=====")
+        env.AddHeader('tgt', 'src')
+    </sconstruct>
+
+    <para>
+
+      The <function>TOOL_ADD_HEADER</function> tool method will be
+      called to add the <function>AddHeader</function> tool to the
+      environment.
+
+    </para>
+
+    <!-- 
+    <scons_output example="site1" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+    -->
+
+    <para>
+      Similarly, a more full-fledged tool with
+      <function>exists()</function> and <function>generate()</function>
+      methods can be installed in
+      <filename>site_scons/site_tools/toolname.py</filename>.  Since
+      <filename>site_scons/site_tools</filename> is automatically added
+      to the head of the tool search path, any tool found there will be
+      available to all environments.  Furthermore, a tool found there
+      will override a built-in tool of the same name, so if you need to
+      change the behavior of a built-in tool, site_scons gives you the
+      hook you need.
+    </para>
+
+    <para>
+      Many people have a library of utility Python functions they'd like
+      to include in &SConscript;s; just put that module in
+      <filename>site_scons/my_utils.py</filename> or any valid Python module name of your
+      choice.  For instance you can do something like this in
+      <filename>site_scons/my_utils.py</filename> to add build_id and MakeWorkDir functions:
+    </para>
+      
+    <scons_example name="site2">
+      <file name="site_scons/my_utils.py" printme=1>
+        from SCons.Script import *   # for Execute and Mkdir
+        def build_id():
+           """Return a build ID (stub version)"""
+           return "100"
+        def MakeWorkDir(workdir):
+           """Create the specified dir immediately"""
+           Execute(Mkdir(workdir))
+      </file>
+      <file name="SConscript">
+        import my_utils
+        MakeWorkDir('/tmp/work')
+        print "build_id=" + my_utils.build_id()
+      </file>
+    </scons_example>
+
+    <para>
+
+    And then in your &SConscript; or any sub-&SConscript; anywhere in
+    your build, you can import <filename>my_utils</filename> and use it:
+
+    </para>
+
+    <sconstruct>
+        import my_utils
+        print "build_id=" + my_utils.build_id()
+        my_utils.MakeWorkDir('/tmp/work')
+    </sconstruct>
+
+    <para>
+      Note that although you can put this library in
+      <filename>site_scons/site_init.py</filename>,
+      it is no better there than <filename>site_scons/my_utils.py</filename>
+      since you still have to import that module into your &SConscript;.
+      Also note that in order to refer to objects in the SCons namespace
+      such as &Environment; or &Mkdir; or &Execute; in any file other
+      than a &SConstruct; or &SConscript; you always need to do
+    </para>
+    <sconstruct>
+        from SCons.Script import *
+    </sconstruct>
+
+    <para>
+      This is true in modules in <filename>site_scons</filename> such as
+      <filename>site_scons/site_init.py</filename> as well.
+    </para>
+
+    <para>
+
+      If you have a machine-wide site dir you'd like to use instead of
+      <filename>./site_scons</filename>, use the
+      <literal>--site-dir</literal> option to point to your dir.
+      <filename>site_init.py</filename> and
+      <filename>site_tools</filename> will be located under that dir.
+      To avoid using a <filename>site_scons</filename> dir at all, even
+      if it exists, use the <literal>--no-site-dir</literal> option.
+
+    </para>
+
+  </section>
+
+
+  <!--
+
+  <section>
+  <title>Builders That Use Other Builders</title>
+
+    <para>
+
+    XXX para
+
+    </para>
+
+    <scons_example name="ex8">
+       <file name="SConstruct" printme="1">
+       env = Environment()
+       #env.SourceCode('.', env.BitKeeper('my_command'))
+       env.Program('hello.c')
+       </file>
+       <file name="hello.c">
+       hello.c
+       </file>
+    </scons_example>
+
+    <scons_output example="ex8">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  -->
diff --git a/doc/user/builders-writing.xml b/doc/user/builders-writing.xml
new file mode 100644
index 0000000..b05cce6
--- /dev/null
+++ b/doc/user/builders-writing.xml
@@ -0,0 +1,953 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head2 Adding new methods
+
+For slightly more demanding changes, you may wish to add new methods to the
+C<cons> package. Here's an example of a very simple extension,
+C<InstallScript>, which installs a tcl script in a requested location, but
+edits the script first to reflect a platform-dependent path that needs to be
+installed in the script:
+
+  # cons::InstallScript - Create a platform dependent version of a shell
+  # script by replacing string ``#!your-path-here'' with platform specific
+  # path $BIN_DIR.
+
+  sub cons::InstallScript {
+	my ($env, $dst, $src) = @_;
+	Command $env $dst, $src, qq(
+		sed s+your-path-here+$BIN_DIR+ %< > %>
+		chmod oug+x %>
+	);
+  }
+
+Notice that this method is defined directly in the C<cons> package (by
+prefixing the name with C<cons::>). A change made in this manner will be
+globally visible to all environments, and could be called as in the
+following example:
+
+  InstallScript $env "$BIN/foo", "foo.tcl";
+
+For a small improvement in generality, the C<BINDIR> variable could be
+passed in as an argument or taken from the construction environment-,-as
+C<%BINDIR>.
+
+
+=head2 Overriding methods
+
+Instead of adding the method to the C<cons> name space, you could define a
+new package which inherits existing methods from the C<cons> package and
+overrides or adds others. This can be done using Perl's inheritance
+mechanisms.
+
+The following example defines a new package C<cons::switch> which
+overrides the standard C<Library> method. The overridden method builds
+linked library modules, rather than library archives. A new
+constructor is provided. Environments created with this constructor
+will have the new library method; others won't.
+
+  package cons::switch;
+  BEGIN {@ISA = 'cons'}
+
+  sub new {
+	shift;
+	bless new cons(@_);
+  }
+
+  sub Library {
+	my($env) = shift;
+	my($lib) = shift;
+	my(@objs) = Objects $env @_;
+	Command $env $lib, @objs, q(
+		%LD -r %LDFLAGS %< -o %>
+	);
+  }
+
+This functionality could be invoked as in the following example:
+
+  $env = new cons::switch(@overrides);
+  ...
+  Library $env 'lib.o', 'foo.c', 'bar.c';
+
+-->
+
+  <para>
+
+  Although &SCons; provides many useful methods
+  for building common software products:
+  programs, libraries, documents.
+  you frequently want to be
+  able to build some other type of file
+  not supported directly by &SCons;.
+  Fortunately, &SCons; makes it very easy
+  to define your own &Builder; objects
+  for any custom file types you want to build.
+  (In fact, the &SCons; interfaces for creating
+  &Builder; objects are flexible enough and easy enough to use
+  that all of the the &SCons; built-in &Builder; objects
+  are created the mechanisms described in this section.)
+
+  </para>
+
+  <section>
+  <title>Writing Builders That Execute External Commands</title>
+
+    <para>
+
+    The simplest &Builder; to create is
+    one that executes an external command.
+    For example, if we want to build
+    an output file by running the contents
+    of the input file through a command named
+    <literal>foobuild</literal>,
+    creating that &Builder; might look like:
+
+    </para>
+
+    <programlisting>
+       bld = Builder(action = 'foobuild < $SOURCE > $TARGET')
+    </programlisting>
+
+    <para>
+
+    All the above line does is create a free-standing
+    &Builder; object.
+    The next section will show us how to actually use it.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Attaching a Builder to a &ConsEnv;</title>
+
+    <para>
+
+    A &Builder; object isn't useful
+    until it's attached to a &consenv;
+    so that we can call it to arrange
+    for files to be built.
+    This is done through the &cv-link-BUILDERS;
+    &consvar; in an environment.
+    The &cv-BUILDERS; variable is a Python dictionary
+    that maps the names by which you want to call
+    various &Builder; objects to the objects themselves.
+    For example, if we want to call the
+    &Builder; we just defined by the name
+    <function>Foo</function>,
+    our &SConstruct; file might look like:
+
+    </para>
+
+    
+
+    <programlisting>
+       bld = Builder(action = 'foobuild < $SOURCE > $TARGET')
+       env = Environment(BUILDERS = {'Foo' : bld})
+    </programlisting>
+
+    <para>
+
+    With the &Builder; attached to our &consenv;
+    with the name <function>Foo</function>,
+    we can now actually call it like so:
+
+    </para>
+
+    <programlisting>
+       env.Foo('file.foo', 'file.input')
+    </programlisting>
+
+    <para>
+
+    Then when we run &SCons; it looks like:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      foobuild &lt; file.input &gt; file.foo
+    </screen>
+
+    <para>
+
+    Note, however, that the default &cv-BUILDERS;
+    variable in a &consenv;
+    comes with a default set of &Builder; objects
+    already defined:
+    &b-link-Program;, &b-link-Library;, etc.
+    And when we explicitly set the &cv-BUILDERS; variable
+    when we create the &consenv;,
+    the default &Builder;s are no longer part of
+    the environment:
+
+    </para>
+
+   <!--
+   The ToolSurrogate stuff that's used to capture output initializes
+   SCons.Defaults.ConstructionEnvironment with its own list of TOOLS.
+   In this next example, we want to show the user that when they
+   set the BUILDERS explicitly, the call to env.Program() generates
+   an AttributeError.  This won't happen with all of the default
+   ToolSurrogates in the default construction environment.  To make the
+   AttributeError show up, we have to overwite the default construction
+   environment's TOOLS variable so Program() builder doesn't show up.
+
+   We do this by executing a slightly different SConstruct file than the
+   one we print in the guide, with two extra statements at the front
+   that overwrite the TOOLS variable as described.  Note that we have
+   to jam those statements on to the first line to keep the line number
+   in the generated error consistent with what the user will see in the
+   User's Guide.
+   -->
+    <programlisting>
+       bld = Builder(action = 'foobuild &lt; $SOURCE &gt; $TARGET')
+       env = Environment(BUILDERS = {'Foo' : bld})
+       env.Foo('file.foo', 'file.input')
+       env.Program('hello.c')
+    </programlisting>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      AttributeError: SConsEnvironment instance has no attribute 'Program':
+        File "/home/my/project/SConstruct", line 4:
+          env.Program('hello.c')
+    </screen>
+
+    <para>
+
+    To be able to use both our own defined &Builder; objects
+    and the default &Builder; objects in the same &consenv;,
+    you can either add to the &cv-BUILDERS; variable
+    using the &Append; function:
+
+    </para>
+
+    
+
+    <programlisting>
+       env = Environment()
+       bld = Builder(action = 'foobuild < $SOURCE > $TARGET')
+       env.Append(BUILDERS = {'Foo' : bld})
+       env.Foo('file.foo', 'file.input')
+       env.Program('hello.c')
+    </programlisting>
+
+    <para>
+
+    Or you can explicitly set the appropriately-named
+    key in the &cv-BUILDERS; dictionary:
+
+    </para>
+
+    <programlisting>
+       env = Environment()
+       bld = Builder(action = 'foobuild < $SOURCE > $TARGET')
+       env['BUILDERS']['Foo'] = bld
+       env.Foo('file.foo', 'file.input')
+       env.Program('hello.c')
+    </programlisting>
+
+    <para>
+
+    Either way, the same &consenv;
+    can then use both the newly-defined
+    <function>Foo</function> &Builder;
+    and the default &b-link-Program; &Builder;:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      foobuild &lt; file.input &gt; file.foo
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Letting &SCons; Handle The File Suffixes</title>
+
+    <para>
+
+    By supplying additional information
+    when you create a &Builder;,
+    you can let &SCons; add appropriate file
+    suffixes to the target and/or the source file.
+    For example, rather than having to specify
+    explicitly that you want the <literal>Foo</literal>
+    &Builder; to build the <literal>file.foo</literal>
+    target file from the <literal>file.input</literal> source file,
+    you can give the <literal>.foo</literal>
+    and <literal>.input</literal> suffixes to the &Builder;,
+    making for more compact and readable calls to
+    the <literal>Foo</literal> &Builder;:
+
+    </para>
+
+    
+
+    <programlisting>
+       bld = Builder(action = 'foobuild < $SOURCE > $TARGET',
+                     suffix = '.foo',
+                     src_suffix = '.input')
+       env = Environment(BUILDERS = {'Foo' : bld})
+       env.Foo('file1')
+       env.Foo('file2')
+    </programlisting>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      foobuild &lt; file1.input &gt; file1.foo
+      foobuild &lt; file2.input &gt; file2.foo
+    </screen>
+
+    <para>
+
+    You can also supply a <literal>prefix</literal> keyword argument
+    if it's appropriate to have &SCons; append a prefix
+    to the beginning of target file names.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Builders That Execute Python Functions</title>
+
+    <para>
+
+    In &SCons;, you don't have to call an external command
+    to build a file.
+    You can, instead, define a Python function
+    that a &Builder; object can invoke
+    to build your target file (or files).
+    Such a &buildfunc; definition looks like:
+
+    </para>
+
+    <programlisting>
+       def build_function(target, source, env):
+           # Code to build "target" from "source"
+           return None
+    </programlisting>
+
+    <para>
+
+    The arguments of a &buildfunc; are:
+
+    </para>
+
+    <variablelist>
+
+      <varlistentry>
+      <term>target</term>
+
+      <listitem>
+      <para>
+
+      A list of Node objects representing
+      the target or targets to be
+      built by this builder function.
+      The file names of these target(s)
+      may be extracted using the Python &str; function.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>source</term>
+
+      <listitem>
+      <para>
+
+      A list of Node objects representing
+      the sources to be
+      used by this builder function to build the targets.
+      The file names of these source(s)
+      may be extracted using the Python &str; function.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>env</term>
+
+      <listitem>
+      <para>
+
+      The &consenv; used for building the target(s).
+      The builder function may use any of the
+      environment's construction variables
+      in any way to affect how it builds the targets.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+    </variablelist>
+
+    <para>
+
+    The builder function must
+    return a <literal>0</literal> or <literal>None</literal> value
+    if the target(s) are built successfully.
+    The builder function
+    may raise an exception
+    or return any non-zero value
+    to indicate that the build is unsuccessful,
+
+    </para>
+
+    <para>
+
+    Once you've defined the Python function
+    that will build your target file,
+    defining a &Builder; object for it is as
+    simple as specifying the name of the function,
+    instead of an external command,
+    as the &Builder;'s
+    <literal>action</literal>
+    argument:
+
+    </para>
+
+    <programlisting>
+       def build_function(target, source, env):
+           # Code to build "target" from "source"
+           return None
+       bld = Builder(action = build_function,
+                     suffix = '.foo',
+                     src_suffix = '.input')
+       env = Environment(BUILDERS = {'Foo' : bld})
+       env.Foo('file')
+    </programlisting>
+
+    <para>
+
+    And notice that the output changes slightly,
+    reflecting the fact that a Python function,
+    not an external command,
+    is now called to build the target file:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      build_function(["file.foo"], ["file.input"])
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Builders That Create Actions Using a &Generator;</title>
+
+    <para>
+
+    &SCons; Builder objects can create an action "on the fly"
+    by using a function called a &generator;.
+    This provides a great deal of flexibility to
+    construct just the right list of commands
+    to build your target.
+    A &generator; looks like:
+
+    </para>
+
+    <programlisting>
+       def generate_actions(source, target, env, for_signature):
+           return 'foobuild < %s > %s' % (target[0], source[0])
+    </programlisting>
+
+    <para>
+
+    The arguments of a &generator; are:
+
+    </para>
+
+    <variablelist>
+
+      <varlistentry>
+      <term>source</term>
+
+      <listitem>
+      <para>
+
+      A list of Node objects representing
+      the sources to be built
+      by the command or other action
+      generated by this function.
+      The file names of these source(s)
+      may be extracted using the Python &str; function.
+
+      </para>
+      </listitem>
+
+      </varlistentry>
+
+      <varlistentry>
+      <term>target</term>
+
+      <listitem>
+      <para>
+
+      A list of Node objects representing
+      the target or targets to be built
+      by the command or other action
+      generated by this function.
+      The file names of these target(s)
+      may be extracted using the Python &str; function.
+
+      </para>
+      </listitem>
+
+      </varlistentry>
+
+      <varlistentry>
+      <term>env</term>
+
+      <listitem>
+      <para>
+
+      The &consenv; used for building the target(s).
+      The generator may use any of the
+      environment's construction variables
+      in any way to determine what command
+      or other action to return.
+
+      </para>
+      </listitem>
+
+      </varlistentry>
+
+      <varlistentry>
+      <term>for_signature</term>
+
+      <listitem>
+      <para>
+
+      A flag that specifies whether the
+      generator is being called to contribute to a build signature,
+      as opposed to actually executing the command.
+
+      <!-- XXX NEED MORE HERE, describe generators use in signatures -->
+
+      </para>
+      </listitem>
+
+      </varlistentry>
+
+    </variablelist>
+
+    <para>
+
+    The &generator; must return a
+    command string or other action that will be used to
+    build the specified target(s) from the specified source(s).
+
+    </para>
+
+    <para>
+
+    Once you've defined a &generator;,
+    you create a &Builder; to use it
+    by specifying the generator keyword argument
+    instead of <literal>action</literal>.
+
+    </para>
+
+    
+
+    <programlisting>
+       def generate_actions(source, target, env, for_signature):
+           return 'foobuild < %s > %s' % (source[0], target[0])
+       bld = Builder(generator = generate_actions,
+                     suffix = '.foo',
+                     src_suffix = '.input')
+       env = Environment(BUILDERS = {'Foo' : bld})
+       env.Foo('file')
+    </programlisting>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      foobuild &lt; file.input &gt; file.foo
+    </screen>
+
+    <para>
+
+    Note that it's illegal to specify both an
+    <literal>action</literal>
+    and a
+    <literal>generator</literal>
+    for a &Builder;.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Builders That Modify the Target or Source Lists Using an &Emitter;</title>
+
+    <para>
+
+    &SCons; supports the ability for a Builder to modify the
+    lists of target(s) from the specified source(s).
+    You do this by defining an &emitter; function
+    that takes as its arguments
+    the list of the targets passed to the builder,
+    the list of the sources passed to the builder,
+    and the construction environment.
+    The emitter function should return the modified
+    lists of targets that should be built
+    and sources from which the targets will be built.
+
+    </para>
+
+    <para>
+
+    For example, suppose you want to define a Builder
+    that always calls a <filename>foobuild</filename> program,
+    and you want to automatically add
+    a new target file named
+    <filename>new_target</filename>
+    and a new source file named
+    <filename>new_source</filename>
+    whenever it's called.
+    The &SConstruct; file might look like this:
+
+    </para>
+
+    
+
+    <programlisting>
+       def modify_targets(target, source, env):
+           target.append('new_target')
+           source.append('new_source')
+           return target, source
+       bld = Builder(action = 'foobuild $TARGETS - $SOURCES',
+                     suffix = '.foo',
+                     src_suffix = '.input',
+                     emitter = modify_targets)
+       env = Environment(BUILDERS = {'Foo' : bld})
+       env.Foo('file')
+    </programlisting>
+
+    <para>
+    
+    And would yield the following output:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      foobuild file.foo new_target - file.input new_source
+    </screen>
+
+    <para>
+
+    One very flexible thing that you can do is
+    use a construction variable to specify
+    different emitter functions for different
+    construction variable.
+    To do this, specify a string
+    containing a construction variable
+    expansion as the emitter when you call
+    the &Builder; function,
+    and set that construction variable to
+    the desired emitter function
+    in different construction environments:
+
+    </para>
+
+    <programlisting>
+        bld = Builder(action = 'my_command $SOURCES &gt; $TARGET',
+                      suffix = '.foo',
+                      src_suffix = '.input',
+                      emitter = '$MY_EMITTER')
+        def modify1(target, source, env):
+            return target, source + ['modify1.in']
+        def modify2(target, source, env):
+            return target, source + ['modify2.in']
+        env1 = Environment(BUILDERS = {'Foo' : bld},
+                           MY_EMITTER = modify1)
+        env2 = Environment(BUILDERS = {'Foo' : bld},
+                           MY_EMITTER = modify2)
+        env1.Foo('file1')
+        env2.Foo('file2')
+        import os
+        env1['ENV']['PATH'] = env2['ENV']['PATH'] + os.pathsep + os.getcwd()
+        env2['ENV']['PATH'] = env2['ENV']['PATH'] + os.pathsep + os.getcwd()
+      
+
+    </programlisting>
+
+    <programlisting>
+      bld = Builder(action = 'my_command $SOURCES > $TARGET',
+                    suffix = '.foo',
+                    src_suffix = '.input',
+                    emitter = '$MY_EMITTER')
+      def modify1(target, source, env):
+          return target, source + ['modify1.in']
+      def modify2(target, source, env):
+          return target, source + ['modify2.in']
+      env1 = Environment(BUILDERS = {'Foo' : bld},
+                         MY_EMITTER = modify1)
+      env2 = Environment(BUILDERS = {'Foo' : bld},
+                         MY_EMITTER = modify2)
+      env1.Foo('file1')
+      env2.Foo('file2')
+      
+    </programlisting>
+
+    <para>
+
+    In this example, the <filename>modify1.in</filename>
+    and <filename>modify2.in</filename> files
+    get added to the source lists
+    of the different commands:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      my_command file1.input modify1.in &gt; file1.foo
+      my_command file2.input modify2.in &gt; file2.foo
+    </screen>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>target_factor=, source_factory=</title>
+
+  </section>
+
+  <section>
+  <title>target_scanner=, source_scanner=</title>
+
+  </section>
+
+  <section>
+  <title>multi=</title>
+
+  </section>
+
+  <section>
+  <title>single_source=</title>
+
+  </section>
+
+  <section>
+  <title>src_builder=</title>
+
+  </section>
+
+  <section>
+  <title>ensure_suffix=</title>
+
+  </section>
+
+  -->
+
+  <section>
+  <title>Where To Put Your Custom Builders and Tools</title>
+
+    <para>
+
+    The <filename>site_scons</filename> directory gives you a place to
+    put Python modules you can import into your SConscripts
+    (site_scons), add-on tools that can integrate into &SCons;
+    (site_scons/site_tools), and a site_scons/site_init.py file that
+    gets read before any &SConstruct; or &SConscript;, allowing you to
+    change &SCons;'s default behavior.
+
+    </para>
+
+    <para>
+
+    If you get a tool from somewhere (the &SCons; wiki or a third party,
+    for instance) and you'd like to use it in your project, the
+    <filename>site_scons</filename> dir is the simplest place to put it.
+    Tools come in two flavors; either a Python function that operates on
+    an &Environment; or a Python file containing two functions, exists()
+    and generate().
+
+    </para>
+
+    <para>
+
+    A single-function Tool can just be included in your
+    <filename>site_scons/site_init.py</filename> file where it will be
+    parsed and made available for use.  For instance, you could have a
+    <filename>site_scons/site_init.py</filename> file like this:
+
+    </para>
+
+    <programlisting>
+        def TOOL_ADD_HEADER(env):
+           """A Tool to add a header from $HEADER to the source file"""
+           add_header = Builder(action=['echo "$HEADER" &gt; $TARGET',
+                                        'cat $SOURCE &gt;&gt; $TARGET'])
+           env.Append(BUILDERS = {'AddHeader' : add_header})
+           env['HEADER'] = '' # set default value
+    </programlisting>
+
+    <para>
+
+    and a &SConstruct; like this:
+
+    </para>
+
+    <programlisting>
+        # Use TOOL_ADD_HEADER from site_scons/site_init.py
+        env=Environment(tools=['default', TOOL_ADD_HEADER], HEADER="=====")
+        env.AddHeader('tgt', 'src')
+    </programlisting>
+
+    <para>
+
+      The <function>TOOL_ADD_HEADER</function> tool method will be
+      called to add the <function>AddHeader</function> tool to the
+      environment.
+
+    </para>
+
+    <!-- 
+    <scons_output example="site1" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+    -->
+
+    <para>
+      Similarly, a more full-fledged tool with
+      <function>exists()</function> and <function>generate()</function>
+      methods can be installed in
+      <filename>site_scons/site_tools/toolname.py</filename>.  Since
+      <filename>site_scons/site_tools</filename> is automatically added
+      to the head of the tool search path, any tool found there will be
+      available to all environments.  Furthermore, a tool found there
+      will override a built-in tool of the same name, so if you need to
+      change the behavior of a built-in tool, site_scons gives you the
+      hook you need.
+    </para>
+
+    <para>
+      Many people have a library of utility Python functions they'd like
+      to include in &SConscript;s; just put that module in
+      <filename>site_scons/my_utils.py</filename> or any valid Python module name of your
+      choice.  For instance you can do something like this in
+      <filename>site_scons/my_utils.py</filename> to add build_id and MakeWorkDir functions:
+    </para>
+      
+    <programlisting>
+        from SCons.Script import *   # for Execute and Mkdir
+        def build_id():
+           """Return a build ID (stub version)"""
+           return "100"
+        def MakeWorkDir(workdir):
+           """Create the specified dir immediately"""
+           Execute(Mkdir(workdir))
+    </programlisting>
+
+    <para>
+
+    And then in your &SConscript; or any sub-&SConscript; anywhere in
+    your build, you can import <filename>my_utils</filename> and use it:
+
+    </para>
+
+    <programlisting>
+        import my_utils
+        print "build_id=" + my_utils.build_id()
+        my_utils.MakeWorkDir('/tmp/work')
+    </programlisting>
+
+    <para>
+      Note that although you can put this library in
+      <filename>site_scons/site_init.py</filename>,
+      it is no better there than <filename>site_scons/my_utils.py</filename>
+      since you still have to import that module into your &SConscript;.
+      Also note that in order to refer to objects in the SCons namespace
+      such as &Environment; or &Mkdir; or &Execute; in any file other
+      than a &SConstruct; or &SConscript; you always need to do
+    </para>
+    <programlisting>
+        from SCons.Script import *
+    </programlisting>
+
+    <para>
+      This is true in modules in <filename>site_scons</filename> such as
+      <filename>site_scons/site_init.py</filename> as well.
+    </para>
+
+    <para>
+
+      If you have a machine-wide site dir you'd like to use instead of
+      <filename>./site_scons</filename>, use the
+      <literal>--site-dir</literal> option to point to your dir.
+      <filename>site_init.py</filename> and
+      <filename>site_tools</filename> will be located under that dir.
+      To avoid using a <filename>site_scons</filename> dir at all, even
+      if it exists, use the <literal>--no-site-dir</literal> option.
+
+    </para>
+
+  </section>
+
+
+  <!--
+
+  <section>
+  <title>Builders That Use Other Builders</title>
+
+    <para>
+
+    XXX para
+
+    </para>
+
+    <scons_example name="ex8">
+       <file name="SConstruct" printme="1">
+       env = Environment()
+       #env.SourceCode('.', env.BitKeeper('my_command'))
+       env.Program('hello.c')
+       </file>
+       <file name="hello.c">
+       hello.c
+       </file>
+    </scons_example>
+
+    <scons_output example="ex8">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  -->
diff --git a/doc/user/builders.in b/doc/user/builders.in
new file mode 100644
index 0000000..a2f94ce
--- /dev/null
+++ b/doc/user/builders.in
@@ -0,0 +1,57 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
+"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd">
+
+<refentry id="Command">
+
+<refmeta>
+<refentrytitle>Command</refentrytitle>
+</refmeta>
+
+<methodsynopsis>
+  <methodname>env.Command</methodname>
+  <methodparam>foo</methodparam>
+  <methodparam>bar</methodparam>
+</methodsynopsis>
+
+</refentry>
+-->
+
+<para>
+
+This appendix contains descriptions of all of the
+Builders that are <emphasis>potentially</emphasis>
+available "out of the box" in this version of SCons.
+
+</para>
+
+<variablelist>
+
+&builders-gen;
+
+</variablelist>
diff --git a/doc/user/builders.xml b/doc/user/builders.xml
new file mode 100644
index 0000000..a2f94ce
--- /dev/null
+++ b/doc/user/builders.xml
@@ -0,0 +1,57 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
+"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd">
+
+<refentry id="Command">
+
+<refmeta>
+<refentrytitle>Command</refentrytitle>
+</refmeta>
+
+<methodsynopsis>
+  <methodname>env.Command</methodname>
+  <methodparam>foo</methodparam>
+  <methodparam>bar</methodparam>
+</methodsynopsis>
+
+</refentry>
+-->
+
+<para>
+
+This appendix contains descriptions of all of the
+Builders that are <emphasis>potentially</emphasis>
+available "out of the box" in this version of SCons.
+
+</para>
+
+<variablelist>
+
+&builders-gen;
+
+</variablelist>
diff --git a/doc/user/caching.in b/doc/user/caching.in
new file mode 100644
index 0000000..31b1103
--- /dev/null
+++ b/doc/user/caching.in
@@ -0,0 +1,502 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  On multi-developer software projects,
+  you can sometimes speed up every developer's builds a lot by
+  allowing them to share the derived files that they build.
+  &SCons; makes this easy, as well as reliable.
+
+  </para>
+
+  <section>
+  <title>Specifying the Shared Cache Directory</title>
+
+    <para>
+
+    To enable sharing of derived files,
+    use the &CacheDir; function
+    in any &SConscript; file:
+
+    </para>
+
+    <scons_example name="ex1">
+       <file name="SConstruct">
+       env = Environment()
+       env.Program('hello.c')
+       CacheDir('cache')
+       </file>
+       <file name="hello.c">
+       hello.c
+       </file>
+       <directory name="cache">
+       </directory>
+       <file name="not_used" printme="1">
+       CacheDir('/usr/local/build_cache')
+       </file>
+    </scons_example>
+
+    <para>
+
+    Note that the directory you specify must already exist
+    and be readable and writable by all developers
+    who will be sharing derived files.
+    It should also be in some central location
+    that all builds will be able to access.
+    In environments where developers are using separate systems
+    (like individual workstations) for builds,
+    this directory would typically be
+    on a shared or NFS-mounted file system.
+
+    </para>
+
+    <para>
+
+    Here's what happens:
+    When a build has a &CacheDir; specified,
+    every time a file is built,
+    it is stored in the shared cache directory
+    along with its MD5 build signature.
+      <footnote>
+      <para>
+      Actually, the MD5 signature is used as the name of the file
+      in the shared cache directory in which the contents are stored.
+      </para>
+      </footnote>
+    On subsequent builds,
+    before an action is invoked to build a file,
+    &SCons; will check the shared cache directory
+    to see if a file with the exact same build
+    signature already exists.
+    If so, the derived file will not be built locally,
+    but will be copied into the local build directory
+    from the shared cache directory,
+    like so:
+
+    </para>
+
+    <scons_output example="ex1">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q -c</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Note that the &CacheDir; feature still calculates
+    MD5 build sigantures for the shared cache file names
+    even if you configure &SCons; to use timestamps
+    to decide if files are up to date.
+    (See the <xref linkend="chap-depends"></xref>
+    chapter for information about the &Decider; function.)
+    Consequently, using &CacheDir; may reduce or eliminate any
+    potential performance improvements
+    from using timestamps for up-to-date decisions.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Keeping Build Output Consistent</title>
+
+    <para>
+
+    One potential drawback to using a shared cache
+    is that the output printed by &SCons;
+    can be inconsistent from invocation to invocation,
+    because any given file may be rebuilt one time
+    and retrieved from the shared cache the next time.
+    This can make analyzing build output more difficult,
+    especially for automated scripts that
+    expect consistent output each time.
+
+    </para>
+
+    <para>
+
+    If, however, you use the <literal>--cache-show</literal> option,
+    &SCons; will print the command line that it
+    <emphasis>would</emphasis> have executed
+    to build the file,
+    even when it is retrieving the file from the shared cache.
+    This makes the build output consistent
+    every time the build is run:
+
+    </para>
+
+    <scons_output example="ex1">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q -c</scons_output_command>
+      <scons_output_command>scons -Q --cache-show</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The trade-off, of course, is that you no longer
+    know whether or not &SCons;
+    has retrieved a derived file from cache
+    or has rebuilt it locally.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Not Using the Shared Cache for Specific Files</title>
+
+    <para>
+
+    You may want to disable caching for certain
+    specific files in your configuration.
+    For example, if you only want to put
+    executable files in a central cache,
+    but not the intermediate object files,
+    you can use the &NoCache;
+    function to specify that the
+    object files should not be cached:
+
+    </para>
+
+    <scons_example name="ex-NoCache">
+       <file name="SConstruct" printme="1">
+       env = Environment()
+       obj = env.Object('hello.c')
+       env.Program('hello.c')
+       CacheDir('cache')
+       NoCache('hello.o')
+       </file>
+       <file name="hello.c">
+       hello.c
+       </file>
+       <directory name="cache">
+       </directory>
+    </scons_example>
+
+    <para>
+
+    Then when you run &scons; after cleaning
+    the built targets,
+    it will recompile the object file locally
+    (since it doesn't exist in the shared cache directory),
+    but still realize that the shared cache directory
+    contains an up-to-date executable program
+    that can be retrieved instead of re-linking:
+
+    </para>
+
+    <!--
+
+    <scons_output example="ex1">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q -c</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q -c</userinput>
+      Removed hello.o
+      Removed hello
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c hello.c
+      Retrieved `hello' from cache
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Disabling the Shared Cache</title>
+
+    <para>
+
+    Retrieving an already-built file
+    from the shared cache
+    is usually a significant time-savings
+    over rebuilding the file,
+    but how much of a savings
+    (or even whether it saves time at all)
+    can depend a great deal on your
+    system or network configuration.
+    For example, retrieving cached files
+    from a busy server over a busy network
+    might end up being slower than
+    rebuilding the files locally.
+
+    </para>
+
+    <para>
+
+    In these cases, you can specify
+    the <literal>--cache-disable</literal>
+    command-line option to tell &SCons;
+    to not retrieve already-built files from the
+    shared cache directory:
+
+    </para>
+
+    <scons_output example="ex1">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q -c</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q -c</scons_output_command>
+      <scons_output_command>scons -Q --cache-disable</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Populating a Shared Cache With Already-Built Files</title>
+
+    <para>
+
+    Sometimes, you may have one or more derived files
+    already built in your local build tree
+    that you wish to make available to other people doing builds.
+    For example, you may find it more effective to perform
+    integration builds with the cache disabled
+    (per the previous section)
+    and only populate the shared cache directory
+    with the built files after the integration build
+    has completed successfully.
+    This way, the cache will only get filled up
+    with derived files that are part of a complete, successful build
+    not with files that might be later overwritten
+    while you debug integration problems.
+
+    </para>
+
+    <para>
+
+    In this case, you can use the
+    the <literal>--cache-force</literal> option
+    to tell &SCons; to put all derived files in the cache,
+    even if the files already exist in your local tree
+    from having been built by a previous invocation:
+
+    </para>
+
+    <scons_output example="ex1">
+      <scons_output_command>scons -Q --cache-disable</scons_output_command>
+      <scons_output_command>scons -Q -c</scons_output_command>
+      <scons_output_command>scons -Q --cache-disable</scons_output_command>
+      <scons_output_command>scons -Q --cache-force</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Notice how the above sample run
+    demonstrates that the <literal>--cache-disable</literal>
+    option avoids putting the built
+    <filename>hello.o</filename>
+    and
+    <filename>hello</filename> files in the cache,
+    but after using the <literal>--cache-force</literal> option,
+    the files have been put in the cache
+    for the next invocation to retrieve.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Minimizing Cache Contention:  the <literal>--random</literal> Option</title>
+
+    <para>
+
+    If you allow multiple builds to update the
+    shared cache directory simultaneously,
+    two builds that occur at the same time
+    can sometimes start "racing"
+    with one another to build the same files
+    in the same order.
+    If, for example,
+    you are linking multiple files into an executable program:
+
+    </para>
+
+    <scons_example name="ex-random">
+       <file name="SConstruct" printme="1">
+       Program('prog',
+               ['f1.c', 'f2.c', 'f3.c', 'f4.c', 'f5.c'])
+       </file>
+       <file name="f1.c">f1.c</file>
+       <file name="f2.c">f2.c</file>
+       <file name="f3.c">f3.c</file>
+       <file name="f4.c">f4.c</file>
+       <file name="f5.c">f5.c</file>
+       <file name="f6.c">f6.c</file>
+    </scons_example>
+
+    <para>
+
+    &SCons; will normally build the input object files
+    on which the program depends in their normal, sorted order:
+
+    </para>
+
+    <scons_output example="ex-random">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    But if two such builds take place simultaneously,
+    they may each look in the cache at nearly the same
+    time and both decide that <filename>f1.o</filename>
+    must be rebuilt and pushed into the shared cache directory,
+    then both decide that <filename>f2.o</filename>
+    must be rebuilt (and pushed into the shared cache directory),
+    then both decide that <filename>f3.o</filename>
+    must be rebuilt...
+    This won't cause any actual build problems--both
+    builds will succeed,
+    generate correct output files,
+    and populate the cache--but
+    it does represent wasted effort.
+
+    </para>
+
+    <para>
+
+    To alleviate such contention for the cache,
+    you can use the <literal>--random</literal> command-line option
+    to tell &SCons; to build dependencies
+    in a random order:
+
+    </para>
+
+    <!--
+
+    The following <screen> output was generated by this:
+
+    <scons_output example="ex-random">
+      <scons_output_command>scons -Q - -random</scons_output_command>
+    </scons_output>
+
+    We captured it directly here to guarantee a "random" order,
+    guarding against the potential for - -random to happen
+    to return things in the original sorted order.
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q --random</userinput>
+      cc -o f3.o -c f3.c
+      cc -o f1.o -c f1.c
+      cc -o f5.o -c f5.c
+      cc -o f2.o -c f2.c
+      cc -o f4.o -c f4.c
+      cc -o prog f1.o f2.o f3.o f4.o f5.o
+    </screen>
+
+    <para>
+
+    Multiple builds using the <literal>--random</literal> option
+    will usually build their dependencies in different,
+    random orders,
+    which minimizes the chances for a lot of
+    contention for same-named files
+    in the shared cache directory.
+    Multiple simultaneous builds might still race to try to build
+    the same target file on occasion,
+    but long sequences of inefficient contention
+    should be rare.
+
+    </para>
+
+    <para>
+
+    Note, of course,
+    the <literal>--random</literal> option
+    will cause the output that &SCons; prints
+    to be inconsistent from invocation to invocation,
+    which may be an issue when
+    trying to compare output from different build runs.
+
+    </para>
+
+    <para>
+
+    If you want to make sure dependencies will be built
+    in a random order without having to specify
+    the <literal>--random</literal> on very command line,
+    you can use the &SetOption; function to
+    set the <literal>random</literal> option
+    within any &SConscript; file:
+
+    </para>
+
+    <scons_example name="ex-random">
+       <file name="SConstruct" printme="1">
+       SetOption('random', 1)
+       Program('prog',
+               ['f1.c', 'f2.c', 'f3.c', 'f4.c', 'f5.c'])
+       </file>
+       <file name="f1.c">f1.c</file>
+       <file name="f2.c">f2.c</file>
+       <file name="f3.c">f3.c</file>
+       <file name="f4.c">f4.c</file>
+       <file name="f5.c">f5.c</file>
+       <file name="f6.c">f6.c</file>
+    </scons_example>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Troubleshooting Shared Caching:  the &cache-debug; Option</title>
+
+    <para>
+
+    XXX describe the - - cache-debug option
+    XXX maybe point to the troubleshooting appendix?
+
+    </para>
+
+  </section>
+
+  -->
+
+  <!--
+
+  <section>
+
+    <para>
+
+    XXX describe CacheDir management:  monitoring, deleting, etc.
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/caching.xml b/doc/user/caching.xml
new file mode 100644
index 0000000..073539c
--- /dev/null
+++ b/doc/user/caching.xml
@@ -0,0 +1,506 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  On multi-developer software projects,
+  you can sometimes speed up every developer's builds a lot by
+  allowing them to share the derived files that they build.
+  &SCons; makes this easy, as well as reliable.
+
+  </para>
+
+  <section>
+  <title>Specifying the Shared Cache Directory</title>
+
+    <para>
+
+    To enable sharing of derived files,
+    use the &CacheDir; function
+    in any &SConscript; file:
+
+    </para>
+
+    <programlisting>
+       CacheDir('/usr/local/build_cache')
+    </programlisting>
+
+    <para>
+
+    Note that the directory you specify must already exist
+    and be readable and writable by all developers
+    who will be sharing derived files.
+    It should also be in some central location
+    that all builds will be able to access.
+    In environments where developers are using separate systems
+    (like individual workstations) for builds,
+    this directory would typically be
+    on a shared or NFS-mounted file system.
+
+    </para>
+
+    <para>
+
+    Here's what happens:
+    When a build has a &CacheDir; specified,
+    every time a file is built,
+    it is stored in the shared cache directory
+    along with its MD5 build signature.
+      <footnote>
+      <para>
+      Actually, the MD5 signature is used as the name of the file
+      in the shared cache directory in which the contents are stored.
+      </para>
+      </footnote>
+    On subsequent builds,
+    before an action is invoked to build a file,
+    &SCons; will check the shared cache directory
+    to see if a file with the exact same build
+    signature already exists.
+    If so, the derived file will not be built locally,
+    but will be copied into the local build directory
+    from the shared cache directory,
+    like so:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q -c</userinput>
+      Removed hello.o
+      Removed hello
+      % <userinput>scons -Q</userinput>
+      Retrieved `hello.o' from cache
+      Retrieved `hello' from cache
+    </screen>
+
+    <para>
+
+    Note that the &CacheDir; feature still calculates
+    MD5 build sigantures for the shared cache file names
+    even if you configure &SCons; to use timestamps
+    to decide if files are up to date.
+    (See the <xref linkend="chap-depends"></xref>
+    chapter for information about the &Decider; function.)
+    Consequently, using &CacheDir; may reduce or eliminate any
+    potential performance improvements
+    from using timestamps for up-to-date decisions.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Keeping Build Output Consistent</title>
+
+    <para>
+
+    One potential drawback to using a shared cache
+    is that the output printed by &SCons;
+    can be inconsistent from invocation to invocation,
+    because any given file may be rebuilt one time
+    and retrieved from the shared cache the next time.
+    This can make analyzing build output more difficult,
+    especially for automated scripts that
+    expect consistent output each time.
+
+    </para>
+
+    <para>
+
+    If, however, you use the <literal>--cache-show</literal> option,
+    &SCons; will print the command line that it
+    <emphasis>would</emphasis> have executed
+    to build the file,
+    even when it is retrieving the file from the shared cache.
+    This makes the build output consistent
+    every time the build is run:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q -c</userinput>
+      Removed hello.o
+      Removed hello
+      % <userinput>scons -Q --cache-show</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+    </screen>
+
+    <para>
+
+    The trade-off, of course, is that you no longer
+    know whether or not &SCons;
+    has retrieved a derived file from cache
+    or has rebuilt it locally.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Not Using the Shared Cache for Specific Files</title>
+
+    <para>
+
+    You may want to disable caching for certain
+    specific files in your configuration.
+    For example, if you only want to put
+    executable files in a central cache,
+    but not the intermediate object files,
+    you can use the &NoCache;
+    function to specify that the
+    object files should not be cached:
+
+    </para>
+
+    <programlisting>
+       env = Environment()
+       obj = env.Object('hello.c')
+       env.Program('hello.c')
+       CacheDir('cache')
+       NoCache('hello.o')
+    </programlisting>
+
+    <para>
+
+    Then when you run &scons; after cleaning
+    the built targets,
+    it will recompile the object file locally
+    (since it doesn't exist in the shared cache directory),
+    but still realize that the shared cache directory
+    contains an up-to-date executable program
+    that can be retrieved instead of re-linking:
+
+    </para>
+
+    <!--
+
+    <scons_output example="ex1">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q -c</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q -c</userinput>
+      Removed hello.o
+      Removed hello
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c hello.c
+      Retrieved `hello' from cache
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Disabling the Shared Cache</title>
+
+    <para>
+
+    Retrieving an already-built file
+    from the shared cache
+    is usually a significant time-savings
+    over rebuilding the file,
+    but how much of a savings
+    (or even whether it saves time at all)
+    can depend a great deal on your
+    system or network configuration.
+    For example, retrieving cached files
+    from a busy server over a busy network
+    might end up being slower than
+    rebuilding the files locally.
+
+    </para>
+
+    <para>
+
+    In these cases, you can specify
+    the <literal>--cache-disable</literal>
+    command-line option to tell &SCons;
+    to not retrieve already-built files from the
+    shared cache directory:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q -c</userinput>
+      Removed hello.o
+      Removed hello
+      % <userinput>scons -Q</userinput>
+      Retrieved `hello.o' from cache
+      Retrieved `hello' from cache
+      % <userinput>scons -Q -c</userinput>
+      Removed hello.o
+      Removed hello
+      % <userinput>scons -Q --cache-disable</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Populating a Shared Cache With Already-Built Files</title>
+
+    <para>
+
+    Sometimes, you may have one or more derived files
+    already built in your local build tree
+    that you wish to make available to other people doing builds.
+    For example, you may find it more effective to perform
+    integration builds with the cache disabled
+    (per the previous section)
+    and only populate the shared cache directory
+    with the built files after the integration build
+    has completed successfully.
+    This way, the cache will only get filled up
+    with derived files that are part of a complete, successful build
+    not with files that might be later overwritten
+    while you debug integration problems.
+
+    </para>
+
+    <para>
+
+    In this case, you can use the
+    the <literal>--cache-force</literal> option
+    to tell &SCons; to put all derived files in the cache,
+    even if the files already exist in your local tree
+    from having been built by a previous invocation:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q --cache-disable</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q -c</userinput>
+      Removed hello.o
+      Removed hello
+      % <userinput>scons -Q --cache-disable</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q --cache-force</userinput>
+      scons: `.' is up to date.
+      % <userinput>scons -Q</userinput>
+      scons: `.' is up to date.
+    </screen>
+
+    <para>
+
+    Notice how the above sample run
+    demonstrates that the <literal>--cache-disable</literal>
+    option avoids putting the built
+    <filename>hello.o</filename>
+    and
+    <filename>hello</filename> files in the cache,
+    but after using the <literal>--cache-force</literal> option,
+    the files have been put in the cache
+    for the next invocation to retrieve.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Minimizing Cache Contention:  the <literal>--random</literal> Option</title>
+
+    <para>
+
+    If you allow multiple builds to update the
+    shared cache directory simultaneously,
+    two builds that occur at the same time
+    can sometimes start "racing"
+    with one another to build the same files
+    in the same order.
+    If, for example,
+    you are linking multiple files into an executable program:
+
+    </para>
+
+    <programlisting>
+       Program('prog',
+               ['f1.c', 'f2.c', 'f3.c', 'f4.c', 'f5.c'])
+    </programlisting>
+
+    <para>
+
+    &SCons; will normally build the input object files
+    on which the program depends in their normal, sorted order:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o f1.o -c f1.c
+      cc -o f2.o -c f2.c
+      cc -o f3.o -c f3.c
+      cc -o f4.o -c f4.c
+      cc -o f5.o -c f5.c
+      cc -o prog f1.o f2.o f3.o f4.o f5.o
+    </screen>
+
+    <para>
+
+    But if two such builds take place simultaneously,
+    they may each look in the cache at nearly the same
+    time and both decide that <filename>f1.o</filename>
+    must be rebuilt and pushed into the shared cache directory,
+    then both decide that <filename>f2.o</filename>
+    must be rebuilt (and pushed into the shared cache directory),
+    then both decide that <filename>f3.o</filename>
+    must be rebuilt...
+    This won't cause any actual build problems--both
+    builds will succeed,
+    generate correct output files,
+    and populate the cache--but
+    it does represent wasted effort.
+
+    </para>
+
+    <para>
+
+    To alleviate such contention for the cache,
+    you can use the <literal>--random</literal> command-line option
+    to tell &SCons; to build dependencies
+    in a random order:
+
+    </para>
+
+    <!--
+
+    The following <screen> output was generated by this:
+
+    <scons_output example="ex-random">
+      <scons_output_command>scons -Q - -random</scons_output_command>
+    </scons_output>
+
+    We captured it directly here to guarantee a "random" order,
+    guarding against the potential for - -random to happen
+    to return things in the original sorted order.
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q --random</userinput>
+      cc -o f3.o -c f3.c
+      cc -o f1.o -c f1.c
+      cc -o f5.o -c f5.c
+      cc -o f2.o -c f2.c
+      cc -o f4.o -c f4.c
+      cc -o prog f1.o f2.o f3.o f4.o f5.o
+    </screen>
+
+    <para>
+
+    Multiple builds using the <literal>--random</literal> option
+    will usually build their dependencies in different,
+    random orders,
+    which minimizes the chances for a lot of
+    contention for same-named files
+    in the shared cache directory.
+    Multiple simultaneous builds might still race to try to build
+    the same target file on occasion,
+    but long sequences of inefficient contention
+    should be rare.
+
+    </para>
+
+    <para>
+
+    Note, of course,
+    the <literal>--random</literal> option
+    will cause the output that &SCons; prints
+    to be inconsistent from invocation to invocation,
+    which may be an issue when
+    trying to compare output from different build runs.
+
+    </para>
+
+    <para>
+
+    If you want to make sure dependencies will be built
+    in a random order without having to specify
+    the <literal>--random</literal> on very command line,
+    you can use the &SetOption; function to
+    set the <literal>random</literal> option
+    within any &SConscript; file:
+
+    </para>
+
+    <programlisting>
+       Program('prog',
+               ['f1.c', 'f2.c', 'f3.c', 'f4.c', 'f5.c'])
+
+       SetOption('random', 1)
+       Program('prog',
+               ['f1.c', 'f2.c', 'f3.c', 'f4.c', 'f5.c'])
+    </programlisting>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Troubleshooting Shared Caching:  the &cache-debug; Option</title>
+
+    <para>
+
+    XXX describe the - - cache-debug option
+    XXX maybe point to the troubleshooting appendix?
+
+    </para>
+
+  </section>
+
+  -->
+
+  <!--
+
+  <section>
+
+    <para>
+
+    XXX describe CacheDir management:  monitoring, deleting, etc.
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/command-line.in b/doc/user/command-line.in
new file mode 100644
index 0000000..686146e
--- /dev/null
+++ b/doc/user/command-line.in
@@ -0,0 +1,2327 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  &SCons; provides a number of ways
+  for the writer of the &SConscript; files
+  to give the users who will run &SCons;
+  a great deal of control over the build execution.
+  The arguments that the user can specify on
+  the command line are broken down into three types:
+
+  </para>
+
+  <variablelist>
+
+    <varlistentry>
+    <term>Options</term>
+
+    <listitem>
+    <para>
+
+    Command-line options always begin with
+    one or two <literal>-</literal> (hyphen) characters.
+    &SCons; provides ways for you to examine
+    and set options values from within your &SConscript; files,
+    as well as the ability to define your own
+    custom options.
+    See <xref linkend="sect-command-line-options"></xref>, below.
+
+    </para>
+    </listitem>
+    </varlistentry>
+
+    <varlistentry>
+    <term>Variables</term>
+
+    <listitem>
+    <para>
+
+    Any command-line argument containing an <literal>=</literal>
+    (equal sign) is considered a variable setting with the form
+    <varname>variable</varname>=<varname>value</varname>
+    &SCons; provides direct access to
+    all of the command-line variable settings,
+    the ability to apply command-line variable settings
+    to construction environments,
+    and functions for configuring 
+    specific types of variables
+    (Boolean values, path names, etc.)
+    with automatic validation of the user's specified values.
+    See <xref linkend="sect-command-line-variables"></xref>, below.
+
+    </para>
+    </listitem>
+    </varlistentry>
+
+    <varlistentry>
+    <term>Targets</term>
+
+    <listitem>
+    <para>
+
+    Any command-line argument that is not an option
+    or a variable setting
+    (does not begin with a hyphen
+    and does not contain an equal sign)
+    is considered a target that the user
+    (presumably) wants &SCons; to build.
+    A list of Node objects representing
+    the target or targets to build.
+    &SCons; provides access to the list of specified targets,
+    as well as ways to set the default list of targets
+    from within the &SConscript; files.
+    See <xref linkend="sect-command-line-targets"></xref>, below.
+
+    </para>
+    </listitem>
+    </varlistentry>
+
+  </variablelist>
+
+  <section id="sect-command-line-options">
+  <title>Command-Line Options</title>
+
+    <para>
+
+    &SCons; has many <emphasis>command-line options</emphasis>
+    that control its behavior.
+    A &SCons; <emphasis>command-line option</emphasis>
+    always begins with one or two <literal>-</literal> (hyphen)
+    characters.
+
+    </para>
+
+    <section>
+    <title>Not Having to Specify Command-Line Options Each Time:  the &SCONSFLAGS; Environment Variable</title>
+
+      <para>
+
+      Users may find themselves supplying
+      the same command-line options every time
+      they run &SCons;.
+      For example, you might find it saves time
+      to specify a value of <literal>-j 2</literal>
+      to have &SCons; run up to two build commands in parallel.
+      To avoid having to type <literal>-j 2</literal> by hand
+      every time,
+      you can set the external environment variable
+      &SCONSFLAGS; to a string containing
+      command-line options that you want &SCons; to use.
+
+      </para>
+
+      <para>
+
+      If, for example,
+      you're using a POSIX shell that's
+      compatible with the Bourne shell,
+      and you always want &SCons; to use the
+      <literal>-Q</literal> option,
+      you can set the &SCONSFLAGS;
+      environment as follows:
+
+      </para>
+
+      <scons_example name="SCONSFLAGS">
+        <file name="SConstruct">
+        def b(target, source, env):
+            pass
+        def s(target, source, env):
+            return "    ... [build output] ..."
+        a = Action(b, strfunction = s)
+        env = Environment(BUILDERS = {'A' : Builder(action=a)})
+        env.A('foo.out', 'foo.in')
+        </file>
+        <file name="foo.in">
+        foo.in
+        </file>
+      </scons_example>
+
+      <scons_output example="SCONSFLAGS">
+        <scons_output_command>scons</scons_output_command>
+        <scons_output_command>export SCONSFLAGS="-Q"</scons_output_command>
+        <scons_output_command environment="SCONSFLAGS=-Q">scons</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Users of &csh;-style shells on POSIX systems
+      can set the &SCONSFLAGS; environment as follows:
+
+      </para>
+
+      <screen>
+        $ <userinput>setenv SCONSFLAGS "-Q"</userinput>
+      </screen>
+
+      <para>
+
+      Windows users may typically want to set the
+      &SCONSFLAGS; in the appropriate tab of the
+      <literal>System Properties</literal> window.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Getting Values Set by Command-Line Options:  the &GetOption; Function</title>
+
+      <para>
+
+      &SCons; provides the &GetOption; function
+      to get the values set by the various command-line options.
+      One common use of this is to check whether or not
+      the <literal>-h</literal> or <literal>--help</literal> option
+      has been specified.
+      Normally, &SCons; does not print its help text
+      until after it has read all of the &SConscript; files,
+      because it's possible that help text has been added
+      by some subsidiary &SConscript; file deep in the
+      source tree hierarchy.
+      Of course, reading all of the &SConscript; files
+      takes extra time.
+
+      </para>
+
+      <para>
+
+      If you know that your configuration does not define
+      any additional help text in subsidiary &SConscript; files,
+      you can speed up the command-line help available to users
+      by using the &GetOption; function to load the
+      subsidiary &SConscript; files only if the
+      the user has <emphasis>not</emphasis> specified
+      the <literal>-h</literal> or <literal>--help</literal> option,
+      like so:
+
+      </para>
+
+      <sconstruct)
+        if not GetOption('help'):
+            SConscript('src/SConscript', export='env')
+      </sconstruct>
+
+      <para>
+
+      In general, the string that you pass to the
+      &GetOption; function to fetch the value of a command-line
+      option setting is the same as the "most common" long option name
+      (beginning with two hyphen characters),
+      although there are some exceptions.
+      The list of &SCons; command-line options
+      and the &GetOption; strings for fetching them,
+      are available in the
+      <xref linkend="sect-command-line-option-strings"></xref> section,
+      below.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Setting Values of Command-Line Options:  the &SetOption; Function</title>
+
+      <para>
+
+      You can also set the values of &SCons;
+      command-line options from within the &SConscript; files
+      by using the &SetOption; function.
+      The strings that you use to set the values of &SCons;
+      command-line options are available in the
+      <xref linkend="sect-command-line-option-strings"></xref> section,
+      below.
+
+      </para>
+
+      <para>
+
+      One use of the &SetOption; function is to
+      specify a value for the <literal>-j</literal>
+      or <literal>--jobs</literal> option,
+      so that users get the improved performance
+      of a parallel build without having to specify the option by hand.
+      A complicating factor is that a good value
+      for the <literal>-j</literal> option is
+      somewhat system-dependent.
+      One rough guideline is that the more processors
+      your system has,
+      the higher you want to set the
+      <literal>-j</literal> value,
+      in order to take advantage of the number of CPUs.
+
+      </para>
+
+      <para>
+
+      For example, suppose the administrators
+      of your development systems
+      have standardized on setting a
+      <varname>NUM_CPU</varname> environment variable
+      to the number of processors on each system.
+      A little bit of Python code
+      to access the environment variable
+      and the &SetOption; function
+      provide the right level of flexibility:
+
+      </para>
+
+      <scons_example name="SetOption">
+        <file name="SConstruct" printme="1">
+        import os
+        num_cpu = int(os.environ.get('NUM_CPU', 2))
+        SetOption('num_jobs', num_cpu)
+        print "running with -j", GetOption('num_jobs')
+        </file>
+        <file name="foo.in">
+        foo.in
+        </file>
+      </scons_example>
+
+      <para>
+
+      The above snippet of code
+      sets the value of the <literal>--jobs</literal> option
+      to the value specified in the
+      <varname>$NUM_CPU</varname> environment variable.
+      (This is one of the exception cases
+      where the string is spelled differently from
+      the from command-line option.
+      The string for fetching or setting the <literal>--jobs</literal>
+      value is <literal>num_jobs</literal>
+      for historical reasons.)
+      The code in this example prints the <literal>num_jobs</literal>
+      value for illustrative purposes.
+      It uses a default value of <literal>2</literal>
+      to provide some minimal parallelism even on
+      single-processor systems:
+
+      </para>
+
+      <scons_output example="SetOption">
+        <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      But if the <varname>$NUM_CPU</varname>
+      environment variable is set,
+      then we use that for the default number of jobs:
+
+      </para>
+
+      <scons_output example="SetOption">
+        <scons_output_command>export NUM_CPU="4"</scons_output_command>
+        <scons_output_command environment="NUM_CPU=4">scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      But any explicit
+      <literal>-j</literal> or <literal>--jobs</literal>
+      value the user specifies an the command line is used first,
+      regardless of whether or not
+      the <varname>$NUM_CPU</varname> environment
+      variable is set:
+
+      </para>
+
+      <scons_output example="SetOption">
+        <scons_output_command>scons -Q -j 7</scons_output_command>
+        <scons_output_command>export NUM_CPU="4"</scons_output_command>
+        <scons_output_command environment="NUM_CPU=4">scons -Q -j 3</scons_output_command>
+      </scons_output>
+
+    </section>
+
+    <section id="sect-command-line-option-strings">
+    <title>Strings for Getting or Setting Values of &SCons; Command-Line Options</title>
+
+      <para>
+
+      The strings that you can pass to the &GetOption;
+      and &SetOption; functions usually correspond to the
+      first long-form option name
+      (beginning with two hyphen characters:  <literal>--</literal>),
+      after replacing any remaining hyphen characters
+      with underscores.
+
+      </para>
+
+      <para>
+
+      The full list of strings and the variables they
+      correspond to is as follows:
+
+      </para>
+
+      <informaltable>
+      <tgroup cols="2" align="left">
+
+      <thead>
+
+      <row>
+      <entry>String for &GetOption; and &SetOption;</entry>
+      <entry>Command-Line Option(s)</entry>
+      </row>
+
+      </thead>
+
+      <tbody>
+
+      <row>
+      <entry><literal>cache_debug</literal></entry>
+      <entry><option>--cache-debug</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>cache_disable</literal></entry>
+      <entry><option>--cache-disable</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>cache_force</literal></entry>
+      <entry><option>--cache-force</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>cache_show</literal></entry>
+      <entry><option>--cache-show</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>clean</literal></entry>
+      <entry><option>-c</option>,
+           <option>--clean</option>,
+           <option>--remove</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>config</literal></entry>
+      <entry><option>--config</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>directory</literal></entry>
+      <entry><option>-C</option>,
+             <option>--directory</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>diskcheck</literal></entry>
+      <entry><option>--diskcheck</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>duplicate</literal></entry>
+      <entry><option>--duplicate</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>file</literal></entry>
+      <entry><option>-f</option>,
+             <option>--file</option>,
+             <option>--makefile </option>,
+             <option>--sconstruct</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>help</literal></entry>
+      <entry><option>-h</option>,
+             <option>--help</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>ignore_errors</literal></entry>
+      <entry><option>--ignore-errors</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>implicit_cache</literal></entry>
+      <entry><option>--implicit-cache</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>implicit_deps_changed</literal></entry>
+      <entry><option>--implicit-deps-changed</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>implicit_deps_unchanged</literal></entry>
+      <entry><option>--implicit-deps-unchanged</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>interactive</literal></entry>
+      <entry><option>--interact</option>,
+             <option>--interactive</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>keep_going</literal></entry>
+      <entry><option>-k</option>,
+             <option>--keep-going</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>max_drift</literal></entry>
+      <entry><option>--max-drift</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>no_exec</literal></entry>
+      <entry><option>-n</option>,
+             <option>--no-exec</option>,
+             <option>--just-print</option>,
+             <option>--dry-run</option>,
+             <option>--recon</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>no_site_dir</literal></entry>
+      <entry><option>--no-site-dir</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>num_jobs</literal></entry>
+      <entry><option>-j</option>,
+             <option>--jobs</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>profile_file</literal></entry>
+      <entry><option>--profile</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>question</literal></entry>
+      <entry><option>-q</option>,
+             <option>--question</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>random</literal></entry>
+      <entry><option>--random</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>repository</literal></entry>
+      <entry><option>-Y</option>,
+             <option>--repository</option>,
+             <option>--srcdir</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>silent</literal></entry>
+      <entry><option>-s</option>,
+             <option>--silent</option>,
+             <option>--quiet</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>site_dir</literal></entry>
+      <entry><option>--site-dir</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>stack_size</literal></entry>
+      <entry><option>--stack-size</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>taskmastertrace_file</literal></entry>
+      <entry><option>--taskmastertrace</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>warn</literal></entry>
+      <entry><option>--warn</option> <option>--warning</option></entry>
+      </row>
+
+      </tbody>
+
+      </tgroup>
+      </informaltable>
+
+    </section>
+
+    <section>
+    <title>Adding Custom Command-Line Options:  the &AddOption; Function</title>
+
+      <para>
+
+      &SCons; also allows you to define your own
+      command-line options with the &AddOption; function.
+      The &AddOption; function takes the same arguments
+      as the <function>optparse.add_option</function> function
+      from the standard Python library.
+      <footnote>
+      <para>
+      The &AddOption; function is,
+      in fact, implemented using a subclass
+      of the <classname>optparse.OptionParser</classname>.
+      </para>
+      </footnote>
+      Once you have added a custom command-line option
+      with the &AddOption; function,
+      the value of the option (if any) is immediately available
+      using the standard &GetOption; function.
+      (The value can also be set using &SetOption;,
+      although that's not very useful in practice
+      because a default value can be specified in
+      directly in the &AddOption; call.)
+
+      </para>
+
+      <para>
+
+      One useful example of using this functionality
+      is to provide a <option>--prefix</option> for users:
+
+      </para>
+
+      <scons_example name="AddOption">
+        <file name="SConstruct" printme="1">
+        AddOption('--prefix',
+                  dest='prefix',
+                  type='string',
+                  nargs=1,
+                  action='store',
+                  metavar='DIR',
+                  help='installation prefix')
+
+        env = Environment(PREFIX = GetOption('prefix'))
+
+        installed_foo = env.Install('$PREFIX/usr/bin', 'foo.in')
+        Default(installed_foo)
+        </file>
+        <file name="foo.in">
+        foo.in
+        </file>
+      </scons_example>
+
+      <para>
+
+      The above code uses the &GetOption; function
+      to set the <varname>$PREFIX</varname>
+      construction variable to any
+      value that the user specifies with a command-line
+      option of <literal>--prefix</literal>.
+      Because <varname>$PREFIX</varname>
+      will expand to a null string if it's not initialized,
+      running &SCons; without the
+      option of <literal>--prefix</literal>
+      will install the file in the
+      <filename>/usr/bin/</filename> directory:
+
+      </para>
+
+      <scons_output example="AddOption">
+        <scons_output_command>scons -Q -n</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      But specifying <literal>--prefix=/tmp/install</literal>
+      on the command line causes the file to be installed in the
+      <filename>/tmp/install/usr/bin/</filename> directory:
+
+      </para>
+
+      <scons_output example="AddOption">
+        <scons_output_command>scons -Q -n --prefix=/tmp/install</scons_output_command>
+      </scons_output>
+
+    </section>
+
+  </section>
+
+  <section id="sect-command-line-variables">
+  <title>Command-Line <varname>variable</varname>=<varname>value</varname> Build Variables</title>
+
+    <para>
+
+    You may want to control various aspects
+    of your build by allowing the user
+    to specify <varname>variable</varname>=<varname>value</varname>
+    values on the command line.
+    For example, suppose you
+    want users to be able to
+    build a debug version of a program
+    by running &SCons; as follows:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q debug=1</userinput>
+    </screen>
+
+    <para>
+
+    &SCons; provides an &ARGUMENTS; dictionary
+    that stores all of the
+    <varname>variable</varname>=<varname>value</varname>
+    assignments from the command line.
+    This allows you to modify
+    aspects of your build in response
+    to specifications on the command line.
+    (Note that unless you want to require
+    that users <emphasis>always</emphasis>
+    specify a variable,
+    you probably want to use
+    the Python
+    <literal>ARGUMENTS.get()</literal> function,
+    which allows you to specify a default value
+    to be used if there is no specification
+    on the command line.)
+
+    </para>
+
+    <para>
+
+    The following code sets the &cv-link-CCFLAGS; construction
+    variable in response to the <varname>debug</varname>
+    flag being set in the &ARGUMENTS; dictionary:
+
+    </para>
+
+    <scons_example name="ARGUMENTS">
+       <file name="SConstruct" printme="1">
+       env = Environment()
+       debug = ARGUMENTS.get('debug', 0)
+       if int(debug):
+           env.Append(CCFLAGS = '-g')
+       env.Program('prog.c')
+       </file>
+       <file name="prog.c">
+       prog.c
+       </file>
+    </scons_example>
+
+    <para>
+
+    This results in the <varname>-g</varname>
+    compiler option being used when
+    <literal>debug=1</literal>
+    is used on the command line:
+
+    </para>
+
+    <scons_output example="ARGUMENTS">
+       <scons_output_command>scons -Q debug=0</scons_output_command>
+       <scons_output_command>scons -Q debug=0</scons_output_command>
+       <scons_output_command>scons -Q debug=1</scons_output_command>
+       <scons_output_command>scons -Q debug=1</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Notice that &SCons; keeps track of
+    the last values used to build the object files,
+    and as a result correctly rebuilds
+    the object and executable files
+    only when the value of the <literal>debug</literal>
+    argument has changed.
+
+    </para>
+
+    <para>
+
+    The &ARGUMENTS; dictionary has two minor drawbacks.
+    First, because it is a dictionary,
+    it can only store one value for each specified keyword,
+    and thus only "remembers" the last setting
+    for each keyword on the command line.
+    This makes the &ARGUMENTS; dictionary
+    inappropriate if users should be able to
+    specify multiple values
+    on the command line for a given keyword.
+    Second, it does not preserve
+    the order in which the variable settings
+    were specified,
+    which is a problem if
+    you want the configuration to
+    behave differently in response
+    to the order in which the build
+    variable settings were specified on the command line.
+
+    </para>
+
+    <para>
+
+    To accomodate these requirements,
+    &SCons; provides an &ARGLIST; variable
+    that gives you direct access to
+    <varname>variable</varname>=<varname>value</varname>
+    settings on the command line,
+    in the exact order they were specified,
+    and without removing any duplicate settings.
+    Each element in the &ARGLIST; variable
+    is itself a two-element list
+    containing the keyword and the value
+    of the setting,
+    and you must loop through,
+    or otherwise select from,
+    the elements of &ARGLIST; to
+    process the specific settings you want
+    in whatever way is appropriate for your configuration.
+    For example,
+    the following code to let the user
+    add to the &CPPDEFINES; construction variable
+    by specifying multiple
+    <varname>define=</varname>
+    settings on the command line:
+
+    </para>
+
+    <scons_example name="ARGLIST">
+       <file name="SConstruct" printme="1">
+       cppdefines = []
+       for key, value in ARGLIST:
+           if key == 'define':
+               cppdefines.append(value)
+       env = Environment(CPPDEFINES = cppdefines)
+       env.Object('prog.c')
+       </file>
+       <file name="prog.c">
+       prog.c
+       </file>
+    </scons_example>
+
+    <para>
+
+    Yields the following output:
+
+    </para>
+
+    <scons_output example="ARGLIST">
+       <scons_output_command>scons -Q define=FOO</scons_output_command>
+       <scons_output_command>scons -Q define=FOO define=BAR</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Note that the &ARGLIST; and &ARGUMENTS;
+    variables do not interfere with each other,
+    but merely provide slightly different views
+    into how the user specified
+    <varname>variable</varname>=<varname>value</varname>
+    settings on the command line.
+    You can use both variables in the same
+    &SCons; configuration.
+    In general, the &ARGUMENTS; dictionary
+    is more convenient to use,
+    (since you can just fetch variable
+    settings through a dictionary access),
+    and the &ARGLIST; list
+    is more flexible
+    (since you can examine the
+    specific order in which
+    the user's command-line variabe settings).
+
+    </para>
+
+    <section>
+    <title>Controlling Command-Line Build Variables</title>
+
+      <para>
+
+      Being able to use a command-line build variable like
+      <literal>debug=1</literal> is handy,
+      but it can be a chore to write specific Python code
+      to recognize each such variable,
+      check for errors and provide appropriate messages,
+      and apply the values to a construction variable.
+      To help with this,
+      &SCons; supports a class to
+      define such build variables easily,
+      and a mechanism to apply the
+      build variables to a construction environment.
+      This allows you to control how the build variables affect
+      construction environments.
+
+      </para>
+
+      <para>
+
+      For example, suppose that you want users to set
+      a &RELEASE; construction variable on the
+      command line whenever the time comes to build
+      a program for release,
+      and that the value of this variable
+      should be added to the command line
+      with the appropriate <literal>-D</literal> option
+      (or other command line option)
+      to pass the value to the C compiler.
+      Here's how you might do that by setting
+      the appropriate value in a dictionary for the
+      &cv-link-CPPDEFINES; construction variable:
+
+      </para>
+
+      <scons_example name="Variables1">
+        <file name="SConstruct" printme="1">
+           vars = Variables()
+           vars.Add('RELEASE', 'Set to 1 to build for release', 0)
+           env = Environment(variables = vars,
+                             CPPDEFINES={'RELEASE_BUILD' : '${RELEASE}'})
+           env.Program(['foo.c', 'bar.c'])
+        </file>
+        <file name="foo.c">
+        foo.c
+        </file>
+        <file name="bar.c">
+        bar.c
+        </file>
+      </scons_example>
+
+      <para>
+
+      This &SConstruct; file first creates a &Variables; object
+      (the <literal>vars = Variables()</literal> call),
+      and then uses the object's &Add;
+      method to indicate that the &RELEASE;
+      variable can be set on the command line,
+      and that its default value will be <literal>0</literal>
+      (the third argument to the &Add; method).
+      The second argument is a line of help text;
+      we'll learn how to use it in the next section.
+
+      </para>
+
+      <para>
+
+      We then pass the created &Variables;
+      object as a &variables; keyword argument
+      to the &Environment; call
+      used to create the construction environment.
+      This then allows a user to set the
+      &RELEASE; build variable on the command line
+      and have the variable show up in
+      the command line used to build each object from
+      a C source file:
+
+      </para>
+
+      <scons_output example="Variables1">
+        <scons_output_command>scons -Q RELEASE=1</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      NOTE:  Before &SCons; release 0.98.1, these build variables
+      were known as "command-line build options."
+      The class was actually named the &Options; class,
+      and in the sections below,
+      the various functions were named
+      &BoolOption;, &EnumOption;, &ListOption;,
+      &PathOption;, &PackageOption; and &AddOptions;.
+      These older names still work,
+      and you may encounter them in older
+      &SConscript; fles,
+      but their use is discouraged
+      and will be officially deprecated some day.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Providing Help for Command-Line Build Variables</title>
+
+      <para>
+
+      To make command-line build variables most useful,
+      you ideally want to provide
+      some help text that will describe
+      the available variables
+      when the user runs <literal>scons -h</literal>.
+      You could write this text by hand,
+      but &SCons; provides an easier way.
+      &Variables; objects support a
+      &GenerateHelpText; method
+      that will, as its name suggests,
+      generate text that describes
+      the various variables that
+      have been added to it.
+      You then pass the output from this method to
+      the &Help; function:
+
+      </para>
+
+      <scons_example name="Variables_Help">
+        <file name="SConstruct" printme="1">
+           vars = Variables('custom.py')
+           vars.Add('RELEASE', 'Set to 1 to build for release', 0)
+           env = Environment(variables = vars)
+           Help(vars.GenerateHelpText(env))
+        </file>
+      </scons_example>
+
+      <para>
+
+      &SCons; will now display some useful text
+      when the <literal>-h</literal> option is used:
+
+      </para>
+
+      <scons_output example="Variables_Help">
+        <scons_output_command>scons -Q -h</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Notice that the help output shows the default value,
+      and the current actual value of the build variable.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Reading Build Variables From a File</title>
+
+      <para>
+
+      Giving the user a way to specify the
+      value of a build variable on the command line
+      is useful,
+      but can still be tedious
+      if users must specify the variable
+      every time they run &SCons;.
+      We can let users provide customized build variable settings
+      in a local file by providing a
+      file name when we create the
+      &Variables; object:
+
+      </para>
+
+      <scons_example name="Variables_custom_py_1">
+        <file name="SConstruct" printme="1">
+           vars = Variables('custom.py')
+           vars.Add('RELEASE', 'Set to 1 to build for release', 0)
+           env = Environment(variables = vars,
+                             CPPDEFINES={'RELEASE_BUILD' : '${RELEASE}'})
+           env.Program(['foo.c', 'bar.c'])
+           Help(vars.GenerateHelpText(env))
+        </file>
+        <file name="foo.c">
+        foo.c
+        </file>
+        <file name="bar.c">
+        bar.c
+        </file>
+        <file name="custom.py">
+        RELEASE = 1
+        </file>
+      </scons_example>
+
+      <para>
+
+      This then allows the user to control the &RELEASE;
+      variable by setting it in the &custom_py; file:
+
+      </para>
+
+      <scons_example_file example="Variables_custom_py_1" name="custom.py"></scons_example_file>
+
+      <para>
+
+      Note that this file is actually executed
+      like a Python script.
+      Now when we run &SCons;:
+
+      </para>
+
+      <scons_output example="Variables_custom_py_1">
+        <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      And if we change the contents of &custom_py; to:
+
+      </para>
+
+      <scons_example name="Variables_custom_py_2">
+        <file name="SConstruct">
+           vars = Variables('custom.py')
+           vars.Add('RELEASE', 'Set to 1 to build for release', 0)
+           env = Environment(variables = vars,
+                             CPPDEFINES={'RELEASE_BUILD' : '${RELEASE}'})
+           env.Program(['foo.c', 'bar.c'])
+           Help(vars.GenerateHelpText(env))
+        </file>
+        <file name="foo.c">
+        foo.c
+        </file>
+        <file name="bar.c">
+        bar.c
+        </file>
+        <file name="custom.py" printme="1">
+        RELEASE = 0
+        </file>
+      </scons_example>
+
+      <para>
+
+      The object files are rebuilt appropriately
+      with the new variable:
+
+      </para>
+
+      <scons_output example="Variables_custom_py_2">
+        <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+    </section>
+
+    <section>
+    <title>Pre-Defined Build Variable Functions</title>
+
+      <para>
+
+      &SCons; provides a number of functions
+      that provide ready-made behaviors
+      for various types of command-line build variables.
+
+      </para>
+
+      <section>
+      <title>True/False Values:  the &BoolVariable; Build Variable Function</title>
+
+        <para>
+
+        It's often handy to be able to specify a
+        variable that controls a simple Boolean variable
+        with a &true; or &false; value.
+        It would be even more handy to accomodate
+        users who have different preferences for how to represent
+        &true; or &false; values.
+        The &BoolVariable; function
+        makes it easy to accomodate these
+        common representations of
+        &true; or &false;.
+
+        </para>
+
+        <para>
+
+        The &BoolVariable; function takes three arguments:
+        the name of the build variable,
+        the default value of the build variable,
+        and the help string for the variable.
+        It then returns appropriate information for
+        passing to the &Add; method of a &Variables; object, like so:
+
+        </para>
+
+        <scons_example name="BoolVariable">
+          <file name="SConstruct" printme="1">
+             vars = Variables('custom.py')
+             vars.Add(BoolVariable('RELEASE', 'Set to build for release', 0))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'RELEASE_BUILD' : '${RELEASE}'})
+             env.Program('foo.c')
+          </file>
+          <file name="foo.c">
+          foo.c
+          </file>
+        </scons_example>
+
+        <para>
+
+        With this build variable,
+        the &RELEASE; variable can now be enabled by
+        setting it to the value <literal>yes</literal>
+        or <literal>t</literal>:
+
+        </para>
+
+        <scons_output example="BoolVariable">
+          <scons_output_command>scons -Q RELEASE=yes foo.o</scons_output_command>
+        </scons_output>
+
+        <scons_output example="BoolVariable">
+          <scons_output_command>scons -Q RELEASE=t foo.o</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        Other values that equate to &true; include
+        <literal>y</literal>,
+        <literal>1</literal>,
+        <literal>on</literal>
+        and
+        <literal>all</literal>.
+
+        </para>
+
+        <para>
+
+        Conversely, &RELEASE; may now be given a &false;
+        value by setting it to
+        <literal>no</literal>
+        or
+        <literal>f</literal>:
+
+        </para>
+
+        <scons_output example="BoolVariable">
+          <scons_output_command>scons -Q RELEASE=no foo.o</scons_output_command>
+        </scons_output>
+
+        <scons_output example="BoolVariable">
+          <scons_output_command>scons -Q RELEASE=f foo.o</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        Other values that equate to &false; include
+        <literal>n</literal>,
+        <literal>0</literal>,
+        <literal>off</literal>
+        and
+        <literal>none</literal>.
+
+        </para>
+
+        <para>
+
+        Lastly, if a user tries to specify
+        any other value,
+        &SCons; supplies an appropriate error message:
+
+        </para>
+
+        <scons_output example="BoolVariable">
+          <scons_output_command>scons -Q RELEASE=bad_value foo.o</scons_output_command>
+        </scons_output>
+
+      </section>
+
+      <section>
+      <title>Single Value From a List:  the &EnumVariable; Build Variable Function</title>
+
+        <para>
+
+        Suppose that we want a user to be able to
+        set a &COLOR; variable
+        that selects a background color to be
+        displayed by an application,
+        but that we want to restrict the
+        choices to a specific set of allowed colors.
+        This can be set up quite easily
+        using the &EnumVariable;,
+        which takes a list of &allowed_values
+        in addition to the variable name,
+        default value,
+        and help text arguments:
+
+        </para>
+
+        <scons_example name="EnumVariable">
+          <file name="SConstruct" printme="1">
+             vars = Variables('custom.py')
+             vars.Add(EnumVariable('COLOR', 'Set background color', 'red',
+                                 allowed_values=('red', 'green', 'blue')))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'COLOR' : '"${COLOR}"'})
+             env.Program('foo.c')
+          </file>
+          <file name="foo.c">
+          foo.c
+          </file>
+        </scons_example>
+
+        <para>
+
+        The user can now explicity set the &COLOR; build variable
+        to any of the specified allowed values:
+
+        </para>
+
+        <scons_output example="EnumVariable">
+          <scons_output_command>scons -Q COLOR=red foo.o</scons_output_command>
+          <scons_output_command>scons -Q COLOR=blue foo.o</scons_output_command>
+          <scons_output_command>scons -Q COLOR=green foo.o</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        But, almost more importantly,
+        an attempt to set &COLOR;
+        to a value that's not in the list
+        generates an error message:
+
+        </para>
+
+        <scons_output example="EnumVariable">
+          <scons_output_command>scons -Q COLOR=magenta foo.o</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        The &EnumVariable; function also supports a way
+        to map alternate names to allowed values.
+        Suppose, for example,
+        that we want to allow the user
+        to use the word <literal>navy</literal> as a synonym for
+        <literal>blue</literal>.
+        We do this by adding a &map; dictionary
+        that will map its key values
+        to the desired legal value:
+
+        </para>
+
+        <scons_example name="EnumVariable_map">
+          <file name="SConstruct" printme="1">
+             vars = Variables('custom.py')
+             vars.Add(EnumVariable('COLOR', 'Set background color', 'red',
+                                 allowed_values=('red', 'green', 'blue'),
+                                 map={'navy':'blue'}))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'COLOR' : '"${COLOR}"'})
+             env.Program('foo.c')
+          </file>
+          <file name="foo.c">
+          foo.c
+          </file>
+        </scons_example>
+
+        <para>
+
+        As desired, the user can then use
+        <literal>navy</literal> on the command line,
+        and &SCons; will translate it into <literal>blue</literal>
+        when it comes time to use the &COLOR;
+        variable to build a target:
+
+        </para>
+
+        <scons_output example="EnumVariable_map">
+          <scons_output_command>scons -Q COLOR=navy foo.o</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        By default, when using the &EnumVariable; function,
+        arguments that differ
+        from the legal values
+        only in case
+        are treated as illegal values:
+
+        </para>
+
+        <scons_output example="EnumVariable">
+          <scons_output_command>scons -Q COLOR=Red foo.o</scons_output_command>
+          <scons_output_command>scons -Q COLOR=BLUE foo.o</scons_output_command>
+          <scons_output_command>scons -Q COLOR=nAvY foo.o</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        The &EnumVariable; function can take an additional
+        &ignorecase; keyword argument that,
+        when set to <literal>1</literal>,
+        tells &SCons; to allow case differences
+        when the values are specified:
+
+        </para>
+
+        <scons_example name="EnumVariable_ic1">
+          <file name="SConstruct" printme="1">
+             vars = Variables('custom.py')
+             vars.Add(EnumVariable('COLOR', 'Set background color', 'red',
+                                 allowed_values=('red', 'green', 'blue'),
+                                 map={'navy':'blue'},
+                                 ignorecase=1))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'COLOR' : '"${COLOR}"'})
+             env.Program('foo.c')
+          </file>
+          <file name="foo.c">
+          foo.c
+          </file>
+        </scons_example>
+
+        <para>
+
+        Which yields the output:
+
+        </para>
+
+        <scons_output example="EnumVariable_ic1">
+          <scons_output_command>scons -Q COLOR=Red foo.o</scons_output_command>
+          <scons_output_command>scons -Q COLOR=BLUE foo.o</scons_output_command>
+          <scons_output_command>scons -Q COLOR=nAvY foo.o</scons_output_command>
+          <scons_output_command>scons -Q COLOR=green foo.o</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        Notice that an &ignorecase; value of <literal>1</literal>
+        preserves the case-spelling that the user supplied.
+        If you want &SCons; to translate the names
+        into lower-case,
+        regardless of the case used by the user,
+        specify an &ignorecase; value of <literal>2</literal>:
+
+        </para>
+
+        <scons_example name="EnumVariable_ic2">
+          <file name="SConstruct" printme="1">
+             vars = Variables('custom.py')
+             vars.Add(EnumVariable('COLOR', 'Set background color', 'red',
+                                 allowed_values=('red', 'green', 'blue'),
+                                 map={'navy':'blue'},
+                                 ignorecase=2))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'COLOR' : '"${COLOR}"'})
+             env.Program('foo.c')
+          </file>
+          <file name="foo.c">
+          foo.c
+          </file>
+        </scons_example>
+
+        <para>
+
+        Now &SCons; will use values of
+        <literal>red</literal>,
+        <literal>green</literal> or
+        <literal>blue</literal>
+        regardless of how the user spells
+        those values on the command line:
+
+        </para>
+
+        <scons_output example="EnumVariable_ic2">
+          <scons_output_command>scons -Q COLOR=Red foo.o</scons_output_command>
+          <scons_output_command>scons -Q COLOR=nAvY foo.o</scons_output_command>
+          <scons_output_command>scons -Q COLOR=GREEN foo.o</scons_output_command>
+        </scons_output>
+
+      </section>
+
+      <section>
+      <title>Multiple Values From a List:  the &ListVariable; Build Variable Function</title>
+
+        <para>
+
+        Another way in which you might want to allow users
+        to control a build variable is to
+        specify a list of one or more legal values.
+        &SCons; supports this through the &ListVariable; function.
+        If, for example, we want a user to be able to set a
+        &COLORS; variable to one or more of the legal list of values:
+
+        </para>
+
+        <scons_example name="ListVariable">
+          <file name="SConstruct" printme="1">
+             vars = Variables('custom.py')
+             vars.Add(ListVariable('COLORS', 'List of colors', 0,
+                                 ['red', 'green', 'blue']))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'COLORS' : '"${COLORS}"'})
+             env.Program('foo.c')
+          </file>
+          <file name="foo.c">
+          foo.c
+          </file>
+        </scons_example>
+
+        <para>
+
+        A user can now specify a comma-separated list
+        of legal values,
+        which will get translated into a space-separated
+        list for passing to the any build commands:
+
+        </para>
+
+        <scons_output example="ListVariable">
+          <scons_output_command>scons -Q COLORS=red,blue foo.o</scons_output_command>
+          <scons_output_command>scons -Q COLORS=blue,green,red foo.o</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        In addition, the &ListVariable; function
+        allows the user to specify explicit keywords of
+        &all; or &none;
+        to select all of the legal values,
+        or none of them, respectively:
+
+        </para>
+
+        <scons_output example="ListVariable">
+          <scons_output_command>scons -Q COLORS=all foo.o</scons_output_command>
+          <scons_output_command>scons -Q COLORS=none foo.o</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        And, of course, an illegal value
+        still generates an error message:
+
+        </para>
+
+        <scons_output example="ListVariable">
+          <scons_output_command>scons -Q COLORS=magenta foo.o</scons_output_command>
+        </scons_output>
+
+      </section>
+
+      <section>
+      <title>Path Names:  the &PathVariable; Build Variable Function</title>
+
+        <para>
+
+        &SCons; supports a &PathVariable; function
+        to make it easy to create a build variable
+        to control an expected path name.
+        If, for example, you need to
+        define a variable in the preprocessor
+        that controls the location of a
+        configuration file:
+
+        </para>
+
+        <scons_example name="PathVariable">
+          <file name="SConstruct" printme="1">
+             vars = Variables('custom.py')
+             vars.Add(PathVariable('CONFIG',
+                                 'Path to configuration file',
+                                 '__ROOT__/etc/my_config'))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'CONFIG_FILE' : '"$CONFIG"'})
+             env.Program('foo.c')
+          </file>
+          <file name="foo.c">
+          foo.c
+          </file>
+          <file name="__ROOT__/etc/my_config">
+          /opt/location
+          </file>
+          <file name="__ROOT__/usr/local/etc/other_config">
+          /opt/location
+          </file>
+        </scons_example>
+
+        <para>
+
+        This then allows the user to
+        override the &CONFIG; build variable
+        on the command line as necessary:
+
+        </para>
+
+        <scons_output example="PathVariable">
+          <scons_output_command>scons -Q foo.o</scons_output_command>
+          <scons_output_command>scons -Q CONFIG=__ROOT__/usr/local/etc/other_config foo.o</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        By default, &PathVariable; checks to make sure
+        that the specified path exists and generates an error if it
+        doesn't:
+
+        </para>
+
+        <scons_output example="PathVariable">
+          <scons_output_command>scons -Q CONFIG=__ROOT__/does/not/exist foo.o</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        &PathVariable; provides a number of methods
+        that you can use to change this behavior.
+        If you want to ensure that any specified paths are,
+        in fact, files and not directories,
+        use the &PathVariable_PathIsFile; method:
+
+        </para>
+
+        <scons_example name="PathIsFile">
+          <file name="SConstruct" printme="1">
+             vars = Variables('custom.py')
+             vars.Add(PathVariable('CONFIG',
+                                 'Path to configuration file',
+                                 '__ROOT__/etc/my_config',
+                                 PathVariable.PathIsFile))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'CONFIG_FILE' : '"$CONFIG"'})
+             env.Program('foo.c')
+          </file>
+          <file name="foo.c">
+          foo.c
+          </file>
+          <file name="__ROOT__/etc/my_config">
+          /opt/location
+          </file>
+        </scons_example>
+
+        <para>
+
+        Conversely, to ensure that any specified paths are
+        directories and not files,
+        use the &PathVariable_PathIsDir; method:
+
+        </para>
+
+        <scons_example name="PathIsDir">
+          <file name="SConstruct" printme="1">
+             vars = Variables('custom.py')
+             vars.Add(PathVariable('DBDIR',
+                                 'Path to database directory',
+                                 '__ROOT__/var/my_dbdir',
+                                 PathVariable.PathIsDir))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'DBDIR' : '"$DBDIR"'})
+             env.Program('foo.c')
+          </file>
+          <file name="foo.c">
+          foo.c
+          </file>
+          <file name="__ROOT__/var/my_dbdir">
+          /opt/location
+          </file>
+        </scons_example>
+
+        <para>
+
+        If you want to make sure that any specified paths
+        are directories,
+        and you would like the directory created
+        if it doesn't already exist,
+        use the &PathVariable_PathIsDirCreate; method:
+
+        </para>
+
+        <scons_example name="PathIsDirCreate">
+          <file name="SConstruct" printme="1">
+             vars = Variables('custom.py')
+             vars.Add(PathVariable('DBDIR',
+                                 'Path to database directory',
+                                 '__ROOT__/var/my_dbdir',
+                                 PathVariable.PathIsDirCreate))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'DBDIR' : '"$DBDIR"'})
+             env.Program('foo.c')
+          </file>
+          <file name="foo.c">
+          foo.c
+          </file>
+          <file name="__ROOT__/var/my_dbdir">
+          /opt/location
+          </file>
+        </scons_example>
+
+        <para>
+
+        Lastly, if you don't care whether the path exists,
+        is a file, or a directory,
+        use the &PathVariable_PathAccept; method
+        to accept any path that the user supplies:
+
+        </para>
+
+        <scons_example name="PathAccept">
+          <file name="SConstruct" printme="1">
+             vars = Variables('custom.py')
+             vars.Add(PathVariable('OUTPUT',
+                                 'Path to output file or directory',
+                                 None,
+                                 PathVariable.PathAccept))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'OUTPUT' : '"$OUTPUT"'})
+             env.Program('foo.c')
+          </file>
+          <file name="foo.c">
+          foo.c
+          </file>
+        </scons_example>
+
+      </section>
+
+      <section>
+      <title>Enabled/Disabled Path Names: the &PackageVariable; Build Variable Function</title>
+
+        <para>
+
+        Sometimes you want to give users
+        even more control over a path name variable,
+        allowing them to explicitly enable or
+        disable the path name
+        by using <literal>yes</literal> or <literal>no</literal> keywords,
+        in addition to allow them
+        to supply an explicit path name.
+        &SCons; supports the &PackageVariable;
+        function to support this:
+
+        </para>
+
+        <scons_example name="PackageVariable">
+          <file name="SConstruct" printme="1">
+             vars = Variables('custom.py')
+             vars.Add(PackageVariable('PACKAGE',
+                                    'Location package',
+                                    '__ROOT__/opt/location'))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'PACKAGE' : '"$PACKAGE"'})
+             env.Program('foo.c')
+          </file>
+          <file name="foo.c">
+          foo.c
+          </file>
+          <file name="__ROOT__/opt/location">
+          /opt/location
+          </file>
+          <file name="__ROOT__/usr/local/location">
+          /opt/location
+          </file>
+        </scons_example>
+
+        <para>
+
+        When the &SConscript; file uses the &PackageVariable; funciton,
+        user can now still use the default
+        or supply an overriding path name,
+        but can now explicitly set the
+        specified variable to a value
+        that indicates the package should be enabled
+        (in which case the default should be used)
+        or disabled:
+
+        </para>
+
+        <scons_output example="PackageVariable">
+          <scons_output_command>scons -Q foo.o</scons_output_command>
+          <scons_output_command>scons -Q PACKAGE=__ROOT__/usr/local/location foo.o</scons_output_command>
+          <scons_output_command>scons -Q PACKAGE=yes foo.o</scons_output_command>
+          <scons_output_command>scons -Q PACKAGE=no foo.o</scons_output_command>
+        </scons_output>
+
+      </section>
+
+    </section>
+
+    <section>
+    <title>Adding Multiple Command-Line Build Variables at Once</title>
+
+      <para>
+
+      Lastly, &SCons; provides a way to add
+      multiple build variables to a &Variables; object at once.
+      Instead of having to call the &Add; method
+      multiple times,
+      you can call the &AddVariables;
+      method with a list of build variables
+      to be added to the object.
+      Each build variable is specified
+      as either a tuple of arguments,
+      just like you'd pass to the &Add; method itself,
+      or as a call to one of the pre-defined
+      functions for pre-packaged command-line build variables.
+      in any order:
+
+      </para>
+
+      <scons_example name="AddVariables_1">
+        <file name="SConstruct" printme="1">
+          vars = Variables()
+          vars.AddVariables(
+              ('RELEASE', 'Set to 1 to build for release', 0),
+              ('CONFIG', 'Configuration file', '/etc/my_config'),
+              BoolVariable('warnings', 'compilation with -Wall and similiar', 1),
+              EnumVariable('debug', 'debug output and symbols', 'no',
+                         allowed_values=('yes', 'no', 'full'),
+                         map={}, ignorecase=0),  # case sensitive
+              ListVariable('shared',
+                         'libraries to build as shared libraries',
+                         'all',
+                         names = list_of_libs),
+              PackageVariable('x11',
+                            'use X11 installed here (yes = search some places)',
+                            'yes'),
+              PathVariable('qtdir', 'where the root of Qt is installed', qtdir),
+          )
+        </file>
+      </scons_example>
+
+      <para>
+      </para>
+
+    </section>
+
+    <section>
+    <title>Handling Unknown Command-Line Build Variables:  the &UnknownVariables; Function</title>
+
+      <para>
+
+      Users may, of course,
+      occasionally misspell variable names in their command-line settings.
+      &SCons; does not generate an error or warning
+      for any unknown variables the users specifies on the command line.
+      (This is in no small part because you may be
+      processing the arguments directly using the &ARGUMENTS; dictionary,
+      and therefore &SCons; can't know in the general case
+      whether a given "misspelled" variable is
+      really unknown and a potential problem,
+      or something that your &SConscript; file
+      will handle directly with some Python code.)
+
+      </para>
+
+      <para>
+
+      If, however, you're using a &Variables; object to
+      define a specific set of command-line build variables
+      that you expect users to be able to set,
+      you may want to provide an error
+      message or warning of your own
+      if the user supplies a variable setting
+      that is <emphasis>not</emphasis> among
+      the defined list of variable names known to the &Variables; object.
+      You can do this by calling the &UnknownVariables;
+      method of the &Variables; object:
+
+      </para>
+
+      <scons_example name="UnknownVariables">
+        <file name="SConstruct" printme="1">
+           vars = Variables(None)
+           vars.Add('RELEASE', 'Set to 1 to build for release', 0)
+           env = Environment(variables = vars,
+                             CPPDEFINES={'RELEASE_BUILD' : '${RELEASE}'})
+           unknown = vars.UnknownVariables()
+           if unknown:
+               print "Unknown variables:", unknown.keys()
+               Exit(1)
+           env.Program('foo.c')
+        </file>
+        <file name="foo.c">
+        foo.c
+        </file>
+      </scons_example>
+
+      <para>
+
+      The &UnknownVariables; method returns a dictionary
+      containing the keywords and values
+      of any variables the user specified on the command line
+      that are <emphasis>not</emphasis>
+      among the variables known to the &Variables; object
+      (from having been specified using
+      the &Variables; object's&Add; method).
+      In the examble above,
+      we check for whether the dictionary
+      returned by the &UnknownVariables; is non-empty,
+      and if so print the Python list
+      containing the names of the unknwown variables
+      and then call the &Exit; function
+      to terminate &SCons;:
+
+      </para>
+
+      <scons_output example="UnknownVariables">
+        <scons_output_command>scons -Q NOT_KNOWN=foo</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Of course, you can process the items in the
+      dictionary returned by the &UnknownVariables; function
+      in any way appropriate to your build configuration,
+      including just printing a warning message
+      but not exiting,
+      logging an error somewhere,
+      etc.
+
+      </para>
+
+      <para>
+
+      Note that you must delay the call of &UnknownVariables;
+      until after you have applied the &Variables; object
+      to a construction environment
+      with the <literal>variables=</literal>
+      keyword argument of an &Environment; call.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <section id="sect-command-line-targets">
+  <title>Command-Line Targets</title>
+
+    <section>
+    <title>Fetching Command-Line Targets: the &COMMAND_LINE_TARGETS; Variable</title>
+
+      <para>
+
+      &SCons; supports a &COMMAND_LINE_TARGETS; variable
+      that lets you fetch the list of targets that the
+      user specified on the command line.
+      You can use the targets to manipulate the
+      build in any way you wish.
+      As a simple example,
+      suppose that you want to print a reminder
+      to the user whenever a specific program is built.
+      You can do this by checking for the
+      target in the &COMMAND_LINE_TARGETS; list:
+
+      </para>
+
+      <scons_example name="COMMAND_LINE_TARGETS">
+        <file name="SConstruct" printme="1">
+        if 'bar' in COMMAND_LINE_TARGETS:
+            print "Don't forget to copy `bar' to the archive!"
+        Default(Program('foo.c'))
+        Program('bar.c')
+        </file>
+        <file name="foo.c">
+        foo.c
+        </file>
+        <file name="bar.c">
+        foo.c
+        </file>
+      </scons_example>
+
+      <para>
+
+      Then, running &SCons; with the default target
+      works as it always does,
+      but explicity specifying the &bar; target
+      on the command line generates the warning message:
+
+      </para>
+
+      <scons_output example="COMMAND_LINE_TARGETS">
+        <scons_output_command>scons -Q</scons_output_command>
+        <scons_output_command>scons -Q bar</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Another practical use for the &COMMAND_LINE_TARGETS; variable
+      might be to speed up a build
+      by only reading certain subsidiary &SConscript;
+      files if a specific target is requested.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Controlling the Default Targets:  the &Default; Function</title>
+
+      <para>
+
+      One of the most basic things you can control
+      is which targets &SCons; will build by default--that is,
+      when there are no targets specified on the command line.
+      As mentioned previously,
+      &SCons; will normally build every target
+      in or below the current directory
+      by default--that is, when you don't
+      explicitly specify one or more targets
+      on the command line.
+      Sometimes, however, you may want
+      to specify explicitly that only
+      certain programs, or programs in certain directories,
+      should be built by default.
+      You do this with the &Default; function:
+
+      </para>
+
+      <scons_example name="Default1">
+         <file name="SConstruct" printme="1">
+         env = Environment()
+         hello = env.Program('hello.c')
+         env.Program('goodbye.c')
+         Default(hello)
+         </file>
+         <file name="hello.c">
+         hello.c
+         </file>
+         <file name="goodbye.c">
+         goodbye.c
+         </file>
+      </scons_example>
+
+      <para>
+
+      This &SConstruct; file knows how to build two programs,
+      &hello; and &goodbye;,
+      but only builds the
+      &hello; program by default:
+
+      </para>
+
+      <scons_output example="Default1">
+         <scons_output_command>scons -Q</scons_output_command>
+         <scons_output_command>scons -Q</scons_output_command>
+         <scons_output_command>scons -Q goodbye</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Note that, even when you use the &Default;
+      function in your &SConstruct; file,
+      you can still explicitly specify the current directory
+      (<literal>.</literal>) on the command line
+      to tell &SCons; to build
+      everything in (or below) the current directory:
+
+      </para>
+
+      <scons_output example="Default1">
+         <scons_output_command>scons -Q .</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      You can also call the &Default;
+      function more than once,
+      in which case each call
+      adds to the list of targets to be built by default:
+
+      </para>
+
+      <scons_example name="Default2">
+         <file name="SConstruct" printme="1">
+         env = Environment()
+         prog1 = env.Program('prog1.c')
+         Default(prog1)
+         prog2 = env.Program('prog2.c')
+         prog3 = env.Program('prog3.c')
+         Default(prog3)
+         </file>
+         <file name="prog1.c">
+         prog1.c
+         </file>
+         <file name="prog2.c">
+         prog2.c
+         </file>
+         <file name="prog3.c">
+         prog3.c
+         </file>
+      </scons_example>
+
+      <para>
+
+      Or you can specify more than one target
+      in a single call to the &Default; function:
+
+      </para>
+
+      <programlisting>
+         env = Environment()
+         prog1 = env.Program('prog1.c')
+         prog2 = env.Program('prog2.c')
+         prog3 = env.Program('prog3.c')
+         Default(prog1, prog3)
+      </programlisting>
+
+      <para>
+
+      Either of these last two examples
+      will build only the
+      <application>prog1</application>
+      and
+      <application>prog3</application>
+      programs by default:
+
+      </para>
+
+      <scons_output example="Default2">
+         <scons_output_command>scons -Q</scons_output_command>
+         <scons_output_command>scons -Q .</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      You can list a directory as
+      an argument to &Default;:
+
+      </para>
+
+      <scons_example name="Default3">
+         <file name="SConstruct" printme="1">
+         env = Environment()
+         env.Program(['prog1/main.c', 'prog1/foo.c'])
+         env.Program(['prog2/main.c', 'prog2/bar.c'])
+         Default('prog1')
+         </file>
+         <directory name="prog1"></directory>
+         <directory name="prog2"></directory>
+         <file name="prog1/main.c">
+         int main() { printf("prog1/main.c\n"); }
+         </file>
+         <file name="prog1/foo.c">
+         int foo() { printf("prog1/foo.c\n"); }
+         </file>
+         <file name="prog2/main.c">
+         int main() { printf("prog2/main.c\n"); }
+         </file>
+         <file name="prog2/bar.c">
+         int bar() { printf("prog2/bar.c\n"); }
+         </file>
+      </scons_example>
+
+      <para>
+
+      In which case only the target(s) in that
+      directory will be built by default:
+
+      </para>
+
+      <scons_output example="Default3">
+         <scons_output_command>scons -Q</scons_output_command>
+         <scons_output_command>scons -Q</scons_output_command>
+         <scons_output_command>scons -Q .</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Lastly, if for some reason you don't want
+      any targets built by default,
+      you can use the Python <literal>None</literal>
+      variable:
+
+      </para>
+
+      <scons_example name="Default4">
+         <file name="SConstruct" printme="1">
+         env = Environment()
+         prog1 = env.Program('prog1.c')
+         prog2 = env.Program('prog2.c')
+         Default(None)
+         </file>
+         <file name="prog1.c">
+         prog1.c
+         </file>
+         <file name="prog2.c">
+         prog2.c
+         </file>
+      </scons_example>
+
+      <para>
+
+      Which would produce build output like:
+
+      </para>
+
+      <scons_output example="Default4">
+         <scons_output_command>scons -Q</scons_output_command>
+         <scons_output_command>scons -Q .</scons_output_command>
+      </scons_output>
+
+      <section>
+      <title>Fetching the List of Default Targets: the &DEFAULT_TARGETS; Variable</title>
+
+        <para>
+
+        &SCons; supports a &DEFAULT_TARGETS; variable
+        that lets you get at the current list of default targets.
+        The &DEFAULT_TARGETS variable has
+        two important differences from the &COMMAND_LINE_TARGETS; variable.
+        First, the &DEFAULT_TARGETS; variable is a list of
+        internal &SCons; nodes,
+        so you need to convert the list elements to strings
+        if you want to print them or look for a specific target name.
+        Fortunately, you can do this easily
+        by using the Python <function>map</function> function
+        to run the list through <function>str</function>:
+
+        </para>
+
+        <scons_example name="DEFAULT_TARGETS_1">
+           <file name="SConstruct" printme="1">
+           prog1 = Program('prog1.c')
+           Default(prog1)
+           print "DEFAULT_TARGETS is", map(str, DEFAULT_TARGETS)
+           </file>
+           <file name="prog1.c">
+           prog1.c
+           </file>
+        </scons_example>
+
+        <para>
+
+        (Keep in mind that all of the manipulation of the
+        &DEFAULT_TARGETS; list takes place during the
+        first phase when &SCons; is reading up the &SConscript; files,
+        which is obvious if
+        we leave off the <literal>-Q</literal> flag when we run &SCons;:)
+
+        </para>
+
+        <scons_output example="DEFAULT_TARGETS_1">
+           <scons_output_command>scons</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        Second,
+        the contents of the &DEFAULT_TARGETS; list change
+        in response to calls to the &Default: function,
+        as you can see from the following &SConstruct; file:
+
+        </para>
+
+        <scons_example name="DEFAULT_TARGETS_2">
+           <file name="SConstruct" printme="1">
+           prog1 = Program('prog1.c')
+           Default(prog1)
+           print "DEFAULT_TARGETS is now", map(str, DEFAULT_TARGETS)
+           prog2 = Program('prog2.c')
+           Default(prog2)
+           print "DEFAULT_TARGETS is now", map(str, DEFAULT_TARGETS)
+           </file>
+           <file name="prog1.c">
+           prog1.c
+           </file>
+           <file name="prog2.c">
+           prog2.c
+           </file>
+        </scons_example>
+
+        <para>
+
+        Which yields the output:
+
+        </para>
+
+        <scons_output example="DEFAULT_TARGETS_2">
+           <scons_output_command>scons</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        In practice, this simply means that you
+        need to pay attention to the order in
+        which you call the &Default; function
+        and refer to the &DEFAULT_TARGETS; list,
+        to make sure that you don't examine the
+        list before you've added the default targets
+        you expect to find in it.
+
+        </para>
+
+      </section>
+
+    </section>
+
+    <section>
+    <title>Fetching the List of Build Targets, Regardless of Origin: the &BUILD_TARGETS; Variable</title>
+
+      <para>
+
+      We've already been introduced to the
+      &COMMAND_LINE_TARGETS; variable,
+      which contains a list of targets specified on the command line,
+      and the &DEFAULT_TARGETS; variable,
+      which contains a list of targets specified
+      via calls to the &Default; method or function.
+      Sometimes, however,
+      you want a list of whatever targets
+      &SCons; will try to build,
+      regardless of whether the targets came from the
+      command line or a &Default; call.
+      You could code this up by hand, as follows:
+
+      </para>
+
+      <sconstruct>
+        if COMMAND_LINE_TARGETS:
+            targets = COMMAND_LINE_TARGETS
+        else:
+            targets = DEFAULT_TARGETS
+      </sconstruct>
+
+      <para>
+
+      &SCons;, however, provides a convenient
+      &BUILD_TARGETS; variable
+      that eliminates the need for this by-hand manipulation.
+      Essentially, the &BUILD_TARGETS; variable
+      contains a list of the command-line targets,
+      if any were specified,
+      and if no command-line targets were specified,
+      it contains a list of the targets specified
+      via the &Default; method or function.
+
+      </para>
+
+      <para>
+
+      Because &BUILD_TARGETS; may contain a list of &SCons; nodes,
+      you must convert the list elements to strings
+      if you want to print them or look for a specific target name,
+      just like the &DEFAULT_TARGETS; list:
+
+      </para>
+
+      <scons_example name="BUILD_TARGETS_1">
+        <file name="SConstruct" printme="1">
+        prog1 = Program('prog1.c')
+        Program('prog2.c')
+        Default(prog1)
+        print "BUILD_TARGETS is", map(str, BUILD_TARGETS)
+        </file>
+        <file name="prog1.c">
+        prog1.c
+        </file>
+        <file name="prog2.c">
+        prog2.c
+        </file>
+      </scons_example>
+
+      <para>
+
+      Notice how the value of &BUILD_TARGETS;
+      changes depending on whether a target is
+      specified on the command line:
+
+      </para>
+
+      <scons_output example="BUILD_TARGETS_1">
+        <scons_output_command>scons -Q</scons_output_command>
+        <scons_output_command>scons -Q prog2</scons_output_command>
+        <scons_output_command>scons -Q -c .</scons_output_command>
+      </scons_output>
+
+    </section>
+
+  </section>
diff --git a/doc/user/command-line.xml b/doc/user/command-line.xml
new file mode 100644
index 0000000..630a9b2
--- /dev/null
+++ b/doc/user/command-line.xml
@@ -0,0 +1,2243 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  &SCons; provides a number of ways
+  for the writer of the &SConscript; files
+  to give the users who will run &SCons;
+  a great deal of control over the build execution.
+  The arguments that the user can specify on
+  the command line are broken down into three types:
+
+  </para>
+
+  <variablelist>
+
+    <varlistentry>
+    <term>Options</term>
+
+    <listitem>
+    <para>
+
+    Command-line options always begin with
+    one or two <literal>-</literal> (hyphen) characters.
+    &SCons; provides ways for you to examine
+    and set options values from within your &SConscript; files,
+    as well as the ability to define your own
+    custom options.
+    See <xref linkend="sect-command-line-options"></xref>, below.
+
+    </para>
+    </listitem>
+    </varlistentry>
+
+    <varlistentry>
+    <term>Variables</term>
+
+    <listitem>
+    <para>
+
+    Any command-line argument containing an <literal>=</literal>
+    (equal sign) is considered a variable setting with the form
+    <varname>variable</varname>=<varname>value</varname>
+    &SCons; provides direct access to
+    all of the command-line variable settings,
+    the ability to apply command-line variable settings
+    to construction environments,
+    and functions for configuring 
+    specific types of variables
+    (Boolean values, path names, etc.)
+    with automatic validation of the user's specified values.
+    See <xref linkend="sect-command-line-variables"></xref>, below.
+
+    </para>
+    </listitem>
+    </varlistentry>
+
+    <varlistentry>
+    <term>Targets</term>
+
+    <listitem>
+    <para>
+
+    Any command-line argument that is not an option
+    or a variable setting
+    (does not begin with a hyphen
+    and does not contain an equal sign)
+    is considered a target that the user
+    (presumably) wants &SCons; to build.
+    A list of Node objects representing
+    the target or targets to build.
+    &SCons; provides access to the list of specified targets,
+    as well as ways to set the default list of targets
+    from within the &SConscript; files.
+    See <xref linkend="sect-command-line-targets"></xref>, below.
+
+    </para>
+    </listitem>
+    </varlistentry>
+
+  </variablelist>
+
+  <section id="sect-command-line-options">
+  <title>Command-Line Options</title>
+
+    <para>
+
+    &SCons; has many <emphasis>command-line options</emphasis>
+    that control its behavior.
+    A &SCons; <emphasis>command-line option</emphasis>
+    always begins with one or two <literal>-</literal> (hyphen)
+    characters.
+
+    </para>
+
+    <section>
+    <title>Not Having to Specify Command-Line Options Each Time:  the &SCONSFLAGS; Environment Variable</title>
+
+      <para>
+
+      Users may find themselves supplying
+      the same command-line options every time
+      they run &SCons;.
+      For example, you might find it saves time
+      to specify a value of <literal>-j 2</literal>
+      to have &SCons; run up to two build commands in parallel.
+      To avoid having to type <literal>-j 2</literal> by hand
+      every time,
+      you can set the external environment variable
+      &SCONSFLAGS; to a string containing
+      command-line options that you want &SCons; to use.
+
+      </para>
+
+      <para>
+
+      If, for example,
+      you're using a POSIX shell that's
+      compatible with the Bourne shell,
+      and you always want &SCons; to use the
+      <literal>-Q</literal> option,
+      you can set the &SCONSFLAGS;
+      environment as follows:
+
+      </para>
+
+      
+
+      <screen>
+        % <userinput>scons</userinput>
+        scons: Reading SConscript files ...
+        scons: done reading SConscript files.
+        scons: Building targets ...
+            ... [build output] ...
+        scons: done building targets.
+        % <userinput>export SCONSFLAGS="-Q"</userinput>
+        % <userinput>scons</userinput>
+            ... [build output] ...
+      </screen>
+
+      <para>
+
+      Users of &csh;-style shells on POSIX systems
+      can set the &SCONSFLAGS; environment as follows:
+
+      </para>
+
+      <screen>
+        $ <userinput>setenv SCONSFLAGS "-Q"</userinput>
+      </screen>
+
+      <para>
+
+      Windows users may typically want to set the
+      &SCONSFLAGS; in the appropriate tab of the
+      <literal>System Properties</literal> window.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Getting Values Set by Command-Line Options:  the &GetOption; Function</title>
+
+      <para>
+
+      &SCons; provides the &GetOption; function
+      to get the values set by the various command-line options.
+      One common use of this is to check whether or not
+      the <literal>-h</literal> or <literal>--help</literal> option
+      has been specified.
+      Normally, &SCons; does not print its help text
+      until after it has read all of the &SConscript; files,
+      because it's possible that help text has been added
+      by some subsidiary &SConscript; file deep in the
+      source tree hierarchy.
+      Of course, reading all of the &SConscript; files
+      takes extra time.
+
+      </para>
+
+      <para>
+
+      If you know that your configuration does not define
+      any additional help text in subsidiary &SConscript; files,
+      you can speed up the command-line help available to users
+      by using the &GetOption; function to load the
+      subsidiary &SConscript; files only if the
+      the user has <emphasis>not</emphasis> specified
+      the <literal>-h</literal> or <literal>--help</literal> option,
+      like so:
+
+      </para>
+
+      <programlisting></programlisting>
+
+      <para>
+
+      In general, the string that you pass to the
+      &GetOption; function to fetch the value of a command-line
+      option setting is the same as the "most common" long option name
+      (beginning with two hyphen characters),
+      although there are some exceptions.
+      The list of &SCons; command-line options
+      and the &GetOption; strings for fetching them,
+      are available in the
+      <xref linkend="sect-command-line-option-strings"></xref> section,
+      below.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Setting Values of Command-Line Options:  the &SetOption; Function</title>
+
+      <para>
+
+      You can also set the values of &SCons;
+      command-line options from within the &SConscript; files
+      by using the &SetOption; function.
+      The strings that you use to set the values of &SCons;
+      command-line options are available in the
+      <xref linkend="sect-command-line-option-strings"></xref> section,
+      below.
+
+      </para>
+
+      <para>
+
+      One use of the &SetOption; function is to
+      specify a value for the <literal>-j</literal>
+      or <literal>--jobs</literal> option,
+      so that users get the improved performance
+      of a parallel build without having to specify the option by hand.
+      A complicating factor is that a good value
+      for the <literal>-j</literal> option is
+      somewhat system-dependent.
+      One rough guideline is that the more processors
+      your system has,
+      the higher you want to set the
+      <literal>-j</literal> value,
+      in order to take advantage of the number of CPUs.
+
+      </para>
+
+      <para>
+
+      For example, suppose the administrators
+      of your development systems
+      have standardized on setting a
+      <varname>NUM_CPU</varname> environment variable
+      to the number of processors on each system.
+      A little bit of Python code
+      to access the environment variable
+      and the &SetOption; function
+      provide the right level of flexibility:
+
+      </para>
+
+      <programlisting>
+        import os
+        num_cpu = int(os.environ.get('NUM_CPU', 2))
+        SetOption('num_jobs', num_cpu)
+        print "running with -j", GetOption('num_jobs')
+      </programlisting>
+
+      <para>
+
+      The above snippet of code
+      sets the value of the <literal>--jobs</literal> option
+      to the value specified in the
+      <varname>$NUM_CPU</varname> environment variable.
+      (This is one of the exception cases
+      where the string is spelled differently from
+      the from command-line option.
+      The string for fetching or setting the <literal>--jobs</literal>
+      value is <literal>num_jobs</literal>
+      for historical reasons.)
+      The code in this example prints the <literal>num_jobs</literal>
+      value for illustrative purposes.
+      It uses a default value of <literal>2</literal>
+      to provide some minimal parallelism even on
+      single-processor systems:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q</userinput>
+        running with -j 2
+        scons: `.' is up to date.
+      </screen>
+
+      <para>
+
+      But if the <varname>$NUM_CPU</varname>
+      environment variable is set,
+      then we use that for the default number of jobs:
+
+      </para>
+
+      <screen>
+        % <userinput>export NUM_CPU="4"</userinput>
+        % <userinput>scons -Q</userinput>
+        running with -j 4
+        scons: `.' is up to date.
+      </screen>
+
+      <para>
+
+      But any explicit
+      <literal>-j</literal> or <literal>--jobs</literal>
+      value the user specifies an the command line is used first,
+      regardless of whether or not
+      the <varname>$NUM_CPU</varname> environment
+      variable is set:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q -j 7</userinput>
+        running with -j 7
+        scons: `.' is up to date.
+        % <userinput>export NUM_CPU="4"</userinput>
+        % <userinput>scons -Q -j 3</userinput>
+        running with -j 3
+        scons: `.' is up to date.
+      </screen>
+
+    </section>
+
+    <section id="sect-command-line-option-strings">
+    <title>Strings for Getting or Setting Values of &SCons; Command-Line Options</title>
+
+      <para>
+
+      The strings that you can pass to the &GetOption;
+      and &SetOption; functions usually correspond to the
+      first long-form option name
+      (beginning with two hyphen characters:  <literal>--</literal>),
+      after replacing any remaining hyphen characters
+      with underscores.
+
+      </para>
+
+      <para>
+
+      The full list of strings and the variables they
+      correspond to is as follows:
+
+      </para>
+
+      <informaltable>
+      <tgroup cols="2" align="left">
+
+      <thead>
+
+      <row>
+      <entry>String for &GetOption; and &SetOption;</entry>
+      <entry>Command-Line Option(s)</entry>
+      </row>
+
+      </thead>
+
+      <tbody>
+
+      <row>
+      <entry><literal>cache_debug</literal></entry>
+      <entry><option>--cache-debug</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>cache_disable</literal></entry>
+      <entry><option>--cache-disable</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>cache_force</literal></entry>
+      <entry><option>--cache-force</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>cache_show</literal></entry>
+      <entry><option>--cache-show</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>clean</literal></entry>
+      <entry><option>-c</option>,
+           <option>--clean</option>,
+           <option>--remove</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>config</literal></entry>
+      <entry><option>--config</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>directory</literal></entry>
+      <entry><option>-C</option>,
+             <option>--directory</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>diskcheck</literal></entry>
+      <entry><option>--diskcheck</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>duplicate</literal></entry>
+      <entry><option>--duplicate</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>file</literal></entry>
+      <entry><option>-f</option>,
+             <option>--file</option>,
+             <option>--makefile </option>,
+             <option>--sconstruct</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>help</literal></entry>
+      <entry><option>-h</option>,
+             <option>--help</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>ignore_errors</literal></entry>
+      <entry><option>--ignore-errors</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>implicit_cache</literal></entry>
+      <entry><option>--implicit-cache</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>implicit_deps_changed</literal></entry>
+      <entry><option>--implicit-deps-changed</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>implicit_deps_unchanged</literal></entry>
+      <entry><option>--implicit-deps-unchanged</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>interactive</literal></entry>
+      <entry><option>--interact</option>,
+             <option>--interactive</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>keep_going</literal></entry>
+      <entry><option>-k</option>,
+             <option>--keep-going</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>max_drift</literal></entry>
+      <entry><option>--max-drift</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>no_exec</literal></entry>
+      <entry><option>-n</option>,
+             <option>--no-exec</option>,
+             <option>--just-print</option>,
+             <option>--dry-run</option>,
+             <option>--recon</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>no_site_dir</literal></entry>
+      <entry><option>--no-site-dir</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>num_jobs</literal></entry>
+      <entry><option>-j</option>,
+             <option>--jobs</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>profile_file</literal></entry>
+      <entry><option>--profile</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>question</literal></entry>
+      <entry><option>-q</option>,
+             <option>--question</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>random</literal></entry>
+      <entry><option>--random</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>repository</literal></entry>
+      <entry><option>-Y</option>,
+             <option>--repository</option>,
+             <option>--srcdir</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>silent</literal></entry>
+      <entry><option>-s</option>,
+             <option>--silent</option>,
+             <option>--quiet</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>site_dir</literal></entry>
+      <entry><option>--site-dir</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>stack_size</literal></entry>
+      <entry><option>--stack-size</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>taskmastertrace_file</literal></entry>
+      <entry><option>--taskmastertrace</option></entry>
+      </row>
+
+      <row>
+      <entry><literal>warn</literal></entry>
+      <entry><option>--warn</option> <option>--warning</option></entry>
+      </row>
+
+      </tbody>
+
+      </tgroup>
+      </informaltable>
+
+    </section>
+
+    <section>
+    <title>Adding Custom Command-Line Options:  the &AddOption; Function</title>
+
+      <para>
+
+      &SCons; also allows you to define your own
+      command-line options with the &AddOption; function.
+      The &AddOption; function takes the same arguments
+      as the <function>optparse.add_option</function> function
+      from the standard Python library.
+      <footnote>
+      <para>
+      The &AddOption; function is,
+      in fact, implemented using a subclass
+      of the <classname>optparse.OptionParser</classname>.
+      </para>
+      </footnote>
+      Once you have added a custom command-line option
+      with the &AddOption; function,
+      the value of the option (if any) is immediately available
+      using the standard &GetOption; function.
+      (The value can also be set using &SetOption;,
+      although that's not very useful in practice
+      because a default value can be specified in
+      directly in the &AddOption; call.)
+
+      </para>
+
+      <para>
+
+      One useful example of using this functionality
+      is to provide a <option>--prefix</option> for users:
+
+      </para>
+
+      <programlisting>
+        AddOption('--prefix',
+                  dest='prefix',
+                  type='string',
+                  nargs=1,
+                  action='store',
+                  metavar='DIR',
+                  help='installation prefix')
+
+        env = Environment(PREFIX = GetOption('prefix'))
+
+        installed_foo = env.Install('$PREFIX/usr/bin', 'foo.in')
+        Default(installed_foo)
+      </programlisting>
+
+      <para>
+
+      The above code uses the &GetOption; function
+      to set the <varname>$PREFIX</varname>
+      construction variable to any
+      value that the user specifies with a command-line
+      option of <literal>--prefix</literal>.
+      Because <varname>$PREFIX</varname>
+      will expand to a null string if it's not initialized,
+      running &SCons; without the
+      option of <literal>--prefix</literal>
+      will install the file in the
+      <filename>/usr/bin/</filename> directory:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q -n</userinput>
+        Install file: "foo.in" as "/usr/bin/foo.in"
+      </screen>
+
+      <para>
+
+      But specifying <literal>--prefix=/tmp/install</literal>
+      on the command line causes the file to be installed in the
+      <filename>/tmp/install/usr/bin/</filename> directory:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q -n --prefix=/tmp/install</userinput>
+        Install file: "foo.in" as "/tmp/install/usr/bin/foo.in"
+      </screen>
+
+    </section>
+
+  </section>
+
+  <section id="sect-command-line-variables">
+  <title>Command-Line <varname>variable</varname>=<varname>value</varname> Build Variables</title>
+
+    <para>
+
+    You may want to control various aspects
+    of your build by allowing the user
+    to specify <varname>variable</varname>=<varname>value</varname>
+    values on the command line.
+    For example, suppose you
+    want users to be able to
+    build a debug version of a program
+    by running &SCons; as follows:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q debug=1</userinput>
+    </screen>
+
+    <para>
+
+    &SCons; provides an &ARGUMENTS; dictionary
+    that stores all of the
+    <varname>variable</varname>=<varname>value</varname>
+    assignments from the command line.
+    This allows you to modify
+    aspects of your build in response
+    to specifications on the command line.
+    (Note that unless you want to require
+    that users <emphasis>always</emphasis>
+    specify a variable,
+    you probably want to use
+    the Python
+    <literal>ARGUMENTS.get()</literal> function,
+    which allows you to specify a default value
+    to be used if there is no specification
+    on the command line.)
+
+    </para>
+
+    <para>
+
+    The following code sets the &cv-link-CCFLAGS; construction
+    variable in response to the <varname>debug</varname>
+    flag being set in the &ARGUMENTS; dictionary:
+
+    </para>
+
+    <programlisting>
+       env = Environment()
+       debug = ARGUMENTS.get('debug', 0)
+       if int(debug):
+           env.Append(CCFLAGS = '-g')
+       env.Program('prog.c')
+    </programlisting>
+
+    <para>
+
+    This results in the <varname>-g</varname>
+    compiler option being used when
+    <literal>debug=1</literal>
+    is used on the command line:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q debug=0</userinput>
+       cc -o prog.o -c prog.c
+       cc -o prog prog.o
+       % <userinput>scons -Q debug=0</userinput>
+       scons: `.' is up to date.
+       % <userinput>scons -Q debug=1</userinput>
+       scons: `.' is up to date.
+       % <userinput>scons -Q debug=1</userinput>
+       scons: `.' is up to date.
+    </screen>
+
+    <para>
+
+    Notice that &SCons; keeps track of
+    the last values used to build the object files,
+    and as a result correctly rebuilds
+    the object and executable files
+    only when the value of the <literal>debug</literal>
+    argument has changed.
+
+    </para>
+
+    <para>
+
+    The &ARGUMENTS; dictionary has two minor drawbacks.
+    First, because it is a dictionary,
+    it can only store one value for each specified keyword,
+    and thus only "remembers" the last setting
+    for each keyword on the command line.
+    This makes the &ARGUMENTS; dictionary
+    inappropriate if users should be able to
+    specify multiple values
+    on the command line for a given keyword.
+    Second, it does not preserve
+    the order in which the variable settings
+    were specified,
+    which is a problem if
+    you want the configuration to
+    behave differently in response
+    to the order in which the build
+    variable settings were specified on the command line.
+
+    </para>
+
+    <para>
+
+    To accomodate these requirements,
+    &SCons; provides an &ARGLIST; variable
+    that gives you direct access to
+    <varname>variable</varname>=<varname>value</varname>
+    settings on the command line,
+    in the exact order they were specified,
+    and without removing any duplicate settings.
+    Each element in the &ARGLIST; variable
+    is itself a two-element list
+    containing the keyword and the value
+    of the setting,
+    and you must loop through,
+    or otherwise select from,
+    the elements of &ARGLIST; to
+    process the specific settings you want
+    in whatever way is appropriate for your configuration.
+    For example,
+    the following code to let the user
+    add to the &CPPDEFINES; construction variable
+    by specifying multiple
+    <varname>define=</varname>
+    settings on the command line:
+
+    </para>
+
+    <programlisting>
+       cppdefines = []
+       for key, value in ARGLIST:
+           if key == 'define':
+               cppdefines.append(value)
+       env = Environment(CPPDEFINES = cppdefines)
+       env.Object('prog.c')
+    </programlisting>
+
+    <para>
+
+    Yields the following output:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q define=FOO</userinput>
+       cc -o prog.o -c -DFOO prog.c
+       % <userinput>scons -Q define=FOO define=BAR</userinput>
+       scons: `.' is up to date.
+    </screen>
+
+    <para>
+
+    Note that the &ARGLIST; and &ARGUMENTS;
+    variables do not interfere with each other,
+    but merely provide slightly different views
+    into how the user specified
+    <varname>variable</varname>=<varname>value</varname>
+    settings on the command line.
+    You can use both variables in the same
+    &SCons; configuration.
+    In general, the &ARGUMENTS; dictionary
+    is more convenient to use,
+    (since you can just fetch variable
+    settings through a dictionary access),
+    and the &ARGLIST; list
+    is more flexible
+    (since you can examine the
+    specific order in which
+    the user's command-line variabe settings).
+
+    </para>
+
+    <section>
+    <title>Controlling Command-Line Build Variables</title>
+
+      <para>
+
+      Being able to use a command-line build variable like
+      <literal>debug=1</literal> is handy,
+      but it can be a chore to write specific Python code
+      to recognize each such variable,
+      check for errors and provide appropriate messages,
+      and apply the values to a construction variable.
+      To help with this,
+      &SCons; supports a class to
+      define such build variables easily,
+      and a mechanism to apply the
+      build variables to a construction environment.
+      This allows you to control how the build variables affect
+      construction environments.
+
+      </para>
+
+      <para>
+
+      For example, suppose that you want users to set
+      a &RELEASE; construction variable on the
+      command line whenever the time comes to build
+      a program for release,
+      and that the value of this variable
+      should be added to the command line
+      with the appropriate <literal>-D</literal> option
+      (or other command line option)
+      to pass the value to the C compiler.
+      Here's how you might do that by setting
+      the appropriate value in a dictionary for the
+      &cv-link-CPPDEFINES; construction variable:
+
+      </para>
+
+      <programlisting>
+           vars = Variables()
+           vars.Add('RELEASE', 'Set to 1 to build for release', 0)
+           env = Environment(variables = vars,
+                             CPPDEFINES={'RELEASE_BUILD' : '${RELEASE}'})
+           env.Program(['foo.c', 'bar.c'])
+      </programlisting>
+
+      <para>
+
+      This &SConstruct; file first creates a &Variables; object
+      (the <literal>vars = Variables()</literal> call),
+      and then uses the object's &Add;
+      method to indicate that the &RELEASE;
+      variable can be set on the command line,
+      and that its default value will be <literal>0</literal>
+      (the third argument to the &Add; method).
+      The second argument is a line of help text;
+      we'll learn how to use it in the next section.
+
+      </para>
+
+      <para>
+
+      We then pass the created &Variables;
+      object as a &variables; keyword argument
+      to the &Environment; call
+      used to create the construction environment.
+      This then allows a user to set the
+      &RELEASE; build variable on the command line
+      and have the variable show up in
+      the command line used to build each object from
+      a C source file:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q RELEASE=1</userinput>
+        cc -o bar.o -c -DRELEASE_BUILD=1 bar.c
+        cc -o foo.o -c -DRELEASE_BUILD=1 foo.c
+        cc -o foo foo.o bar.o
+      </screen>
+
+      <para>
+
+      NOTE:  Before &SCons; release 0.98.1, these build variables
+      were known as "command-line build options."
+      The class was actually named the &Options; class,
+      and in the sections below,
+      the various functions were named
+      &BoolOption;, &EnumOption;, &ListOption;,
+      &PathOption;, &PackageOption; and &AddOptions;.
+      These older names still work,
+      and you may encounter them in older
+      &SConscript; fles,
+      but their use is discouraged
+      and will be officially deprecated some day.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Providing Help for Command-Line Build Variables</title>
+
+      <para>
+
+      To make command-line build variables most useful,
+      you ideally want to provide
+      some help text that will describe
+      the available variables
+      when the user runs <literal>scons -h</literal>.
+      You could write this text by hand,
+      but &SCons; provides an easier way.
+      &Variables; objects support a
+      &GenerateHelpText; method
+      that will, as its name suggests,
+      generate text that describes
+      the various variables that
+      have been added to it.
+      You then pass the output from this method to
+      the &Help; function:
+
+      </para>
+
+      <programlisting>
+           vars = Variables('custom.py')
+           vars.Add('RELEASE', 'Set to 1 to build for release', 0)
+           env = Environment(variables = vars)
+           Help(vars.GenerateHelpText(env))
+      </programlisting>
+
+      <para>
+
+      &SCons; will now display some useful text
+      when the <literal>-h</literal> option is used:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q -h</userinput>
+        
+        RELEASE: Set to 1 to build for release
+            default: 0
+            actual: 0
+        
+        Use scons -H for help about command-line options.
+      </screen>
+
+      <para>
+
+      Notice that the help output shows the default value,
+      and the current actual value of the build variable.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Reading Build Variables From a File</title>
+
+      <para>
+
+      Giving the user a way to specify the
+      value of a build variable on the command line
+      is useful,
+      but can still be tedious
+      if users must specify the variable
+      every time they run &SCons;.
+      We can let users provide customized build variable settings
+      in a local file by providing a
+      file name when we create the
+      &Variables; object:
+
+      </para>
+
+      <programlisting>
+           vars = Variables('custom.py')
+           vars.Add('RELEASE', 'Set to 1 to build for release', 0)
+           env = Environment(variables = vars,
+                             CPPDEFINES={'RELEASE_BUILD' : '${RELEASE}'})
+           env.Program(['foo.c', 'bar.c'])
+           Help(vars.GenerateHelpText(env))
+      </programlisting>
+
+      <para>
+
+      This then allows the user to control the &RELEASE;
+      variable by setting it in the &custom_py; file:
+
+      </para>
+
+      <programlisting>
+        RELEASE = 1
+        </programlisting>
+
+      <para>
+
+      Note that this file is actually executed
+      like a Python script.
+      Now when we run &SCons;:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q</userinput>
+        cc -o bar.o -c -DRELEASE_BUILD=1 bar.c
+        cc -o foo.o -c -DRELEASE_BUILD=1 foo.c
+        cc -o foo foo.o bar.o
+      </screen>
+
+      <para>
+
+      And if we change the contents of &custom_py; to:
+
+      </para>
+
+      <programlisting>
+        RELEASE = 0
+      </programlisting>
+
+      <para>
+
+      The object files are rebuilt appropriately
+      with the new variable:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q</userinput>
+        cc -o bar.o -c -DRELEASE_BUILD=0 bar.c
+        cc -o foo.o -c -DRELEASE_BUILD=0 foo.c
+        cc -o foo foo.o bar.o
+      </screen>
+
+    </section>
+
+    <section>
+    <title>Pre-Defined Build Variable Functions</title>
+
+      <para>
+
+      &SCons; provides a number of functions
+      that provide ready-made behaviors
+      for various types of command-line build variables.
+
+      </para>
+
+      <section>
+      <title>True/False Values:  the &BoolVariable; Build Variable Function</title>
+
+        <para>
+
+        It's often handy to be able to specify a
+        variable that controls a simple Boolean variable
+        with a &true; or &false; value.
+        It would be even more handy to accomodate
+        users who have different preferences for how to represent
+        &true; or &false; values.
+        The &BoolVariable; function
+        makes it easy to accomodate these
+        common representations of
+        &true; or &false;.
+
+        </para>
+
+        <para>
+
+        The &BoolVariable; function takes three arguments:
+        the name of the build variable,
+        the default value of the build variable,
+        and the help string for the variable.
+        It then returns appropriate information for
+        passing to the &Add; method of a &Variables; object, like so:
+
+        </para>
+
+        <programlisting>
+             vars = Variables('custom.py')
+             vars.Add(BoolVariable('RELEASE', 'Set to build for release', 0))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'RELEASE_BUILD' : '${RELEASE}'})
+             env.Program('foo.c')
+        </programlisting>
+
+        <para>
+
+        With this build variable,
+        the &RELEASE; variable can now be enabled by
+        setting it to the value <literal>yes</literal>
+        or <literal>t</literal>:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q RELEASE=yes foo.o</userinput>
+          cc -o foo.o -c -DRELEASE_BUILD=True foo.c
+        </screen>
+
+        <screen>
+          % <userinput>scons -Q RELEASE=t foo.o</userinput>
+          cc -o foo.o -c -DRELEASE_BUILD=True foo.c
+        </screen>
+
+        <para>
+
+        Other values that equate to &true; include
+        <literal>y</literal>,
+        <literal>1</literal>,
+        <literal>on</literal>
+        and
+        <literal>all</literal>.
+
+        </para>
+
+        <para>
+
+        Conversely, &RELEASE; may now be given a &false;
+        value by setting it to
+        <literal>no</literal>
+        or
+        <literal>f</literal>:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q RELEASE=no foo.o</userinput>
+          cc -o foo.o -c -DRELEASE_BUILD=False foo.c
+        </screen>
+
+        <screen>
+          % <userinput>scons -Q RELEASE=f foo.o</userinput>
+          cc -o foo.o -c -DRELEASE_BUILD=False foo.c
+        </screen>
+
+        <para>
+
+        Other values that equate to &false; include
+        <literal>n</literal>,
+        <literal>0</literal>,
+        <literal>off</literal>
+        and
+        <literal>none</literal>.
+
+        </para>
+
+        <para>
+
+        Lastly, if a user tries to specify
+        any other value,
+        &SCons; supplies an appropriate error message:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q RELEASE=bad_value foo.o</userinput>
+          
+          scons: *** Error converting option: RELEASE
+          Invalid value for boolean option: bad_value
+          File "/home/my/project/SConstruct", line 4, in ?
+        </screen>
+
+      </section>
+
+      <section>
+      <title>Single Value From a List:  the &EnumVariable; Build Variable Function</title>
+
+        <para>
+
+        Suppose that we want a user to be able to
+        set a &COLOR; variable
+        that selects a background color to be
+        displayed by an application,
+        but that we want to restrict the
+        choices to a specific set of allowed colors.
+        This can be set up quite easily
+        using the &EnumVariable;,
+        which takes a list of &allowed_values
+        in addition to the variable name,
+        default value,
+        and help text arguments:
+
+        </para>
+
+        <programlisting>
+             vars = Variables('custom.py')
+             vars.Add(EnumVariable('COLOR', 'Set background color', 'red',
+                                 allowed_values=('red', 'green', 'blue')))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'COLOR' : '"${COLOR}"'})
+             env.Program('foo.c')
+        </programlisting>
+
+        <para>
+
+        The user can now explicity set the &COLOR; build variable
+        to any of the specified allowed values:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q COLOR=red foo.o</userinput>
+          cc -o foo.o -c -DCOLOR="red" foo.c
+          % <userinput>scons -Q COLOR=blue foo.o</userinput>
+          scons: `foo.o' is up to date.
+          % <userinput>scons -Q COLOR=green foo.o</userinput>
+          scons: `foo.o' is up to date.
+        </screen>
+
+        <para>
+
+        But, almost more importantly,
+        an attempt to set &COLOR;
+        to a value that's not in the list
+        generates an error message:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q COLOR=magenta foo.o</userinput>
+          
+          scons: *** Invalid value for option COLOR: magenta
+          File "/home/my/project/SConstruct", line 5, in ?
+        </screen>
+
+        <para>
+
+        The &EnumVariable; function also supports a way
+        to map alternate names to allowed values.
+        Suppose, for example,
+        that we want to allow the user
+        to use the word <literal>navy</literal> as a synonym for
+        <literal>blue</literal>.
+        We do this by adding a &map; dictionary
+        that will map its key values
+        to the desired legal value:
+
+        </para>
+
+        <programlisting>
+             vars = Variables('custom.py')
+             vars.Add(EnumVariable('COLOR', 'Set background color', 'red',
+                                 allowed_values=('red', 'green', 'blue'),
+                                 map={'navy':'blue'}))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'COLOR' : '"${COLOR}"'})
+             env.Program('foo.c')
+        </programlisting>
+
+        <para>
+
+        As desired, the user can then use
+        <literal>navy</literal> on the command line,
+        and &SCons; will translate it into <literal>blue</literal>
+        when it comes time to use the &COLOR;
+        variable to build a target:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q COLOR=navy foo.o</userinput>
+          cc -o foo.o -c -DCOLOR="blue" foo.c
+        </screen>
+
+        <para>
+
+        By default, when using the &EnumVariable; function,
+        arguments that differ
+        from the legal values
+        only in case
+        are treated as illegal values:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q COLOR=Red foo.o</userinput>
+          
+          scons: *** Invalid value for option COLOR: Red
+          File "/home/my/project/SConstruct", line 5, in ?
+          % <userinput>scons -Q COLOR=BLUE foo.o</userinput>
+          
+          scons: *** Invalid value for option COLOR: BLUE
+          File "/home/my/project/SConstruct", line 5, in ?
+          % <userinput>scons -Q COLOR=nAvY foo.o</userinput>
+          
+          scons: *** Invalid value for option COLOR: nAvY
+          File "/home/my/project/SConstruct", line 5, in ?
+        </screen>
+
+        <para>
+
+        The &EnumVariable; function can take an additional
+        &ignorecase; keyword argument that,
+        when set to <literal>1</literal>,
+        tells &SCons; to allow case differences
+        when the values are specified:
+
+        </para>
+
+        <programlisting>
+             vars = Variables('custom.py')
+             vars.Add(EnumVariable('COLOR', 'Set background color', 'red',
+                                 allowed_values=('red', 'green', 'blue'),
+                                 map={'navy':'blue'},
+                                 ignorecase=1))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'COLOR' : '"${COLOR}"'})
+             env.Program('foo.c')
+        </programlisting>
+
+        <para>
+
+        Which yields the output:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q COLOR=Red foo.o</userinput>
+          cc -o foo.o -c -DCOLOR="Red" foo.c
+          % <userinput>scons -Q COLOR=BLUE foo.o</userinput>
+          scons: `foo.o' is up to date.
+          % <userinput>scons -Q COLOR=nAvY foo.o</userinput>
+          scons: `foo.o' is up to date.
+          % <userinput>scons -Q COLOR=green foo.o</userinput>
+          scons: `foo.o' is up to date.
+        </screen>
+
+        <para>
+
+        Notice that an &ignorecase; value of <literal>1</literal>
+        preserves the case-spelling that the user supplied.
+        If you want &SCons; to translate the names
+        into lower-case,
+        regardless of the case used by the user,
+        specify an &ignorecase; value of <literal>2</literal>:
+
+        </para>
+
+        <programlisting>
+             vars = Variables('custom.py')
+             vars.Add(EnumVariable('COLOR', 'Set background color', 'red',
+                                 allowed_values=('red', 'green', 'blue'),
+                                 map={'navy':'blue'},
+                                 ignorecase=2))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'COLOR' : '"${COLOR}"'})
+             env.Program('foo.c')
+        </programlisting>
+
+        <para>
+
+        Now &SCons; will use values of
+        <literal>red</literal>,
+        <literal>green</literal> or
+        <literal>blue</literal>
+        regardless of how the user spells
+        those values on the command line:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q COLOR=Red foo.o</userinput>
+          cc -o foo.o -c -DCOLOR="red" foo.c
+          % <userinput>scons -Q COLOR=nAvY foo.o</userinput>
+          scons: `foo.o' is up to date.
+          % <userinput>scons -Q COLOR=GREEN foo.o</userinput>
+          scons: `foo.o' is up to date.
+        </screen>
+
+      </section>
+
+      <section>
+      <title>Multiple Values From a List:  the &ListVariable; Build Variable Function</title>
+
+        <para>
+
+        Another way in which you might want to allow users
+        to control a build variable is to
+        specify a list of one or more legal values.
+        &SCons; supports this through the &ListVariable; function.
+        If, for example, we want a user to be able to set a
+        &COLORS; variable to one or more of the legal list of values:
+
+        </para>
+
+        <programlisting>
+             vars = Variables('custom.py')
+             vars.Add(ListVariable('COLORS', 'List of colors', 0,
+                                 ['red', 'green', 'blue']))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'COLORS' : '"${COLORS}"'})
+             env.Program('foo.c')
+        </programlisting>
+
+        <para>
+
+        A user can now specify a comma-separated list
+        of legal values,
+        which will get translated into a space-separated
+        list for passing to the any build commands:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q COLORS=red,blue foo.o</userinput>
+          cc -o foo.o -c -DCOLORS="red blue" foo.c
+          % <userinput>scons -Q COLORS=blue,green,red foo.o</userinput>
+          scons: `foo.o' is up to date.
+        </screen>
+
+        <para>
+
+        In addition, the &ListVariable; function
+        allows the user to specify explicit keywords of
+        &all; or &none;
+        to select all of the legal values,
+        or none of them, respectively:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q COLORS=all foo.o</userinput>
+          cc -o foo.o -c -DCOLORS="red green blue" foo.c
+          % <userinput>scons -Q COLORS=none foo.o</userinput>
+          scons: `foo.o' is up to date.
+        </screen>
+
+        <para>
+
+        And, of course, an illegal value
+        still generates an error message:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q COLORS=magenta foo.o</userinput>
+          
+          scons: *** Error converting option: COLORS
+          Invalid value(s) for option: magenta
+          File "/home/my/project/SConstruct", line 5, in ?
+        </screen>
+
+      </section>
+
+      <section>
+      <title>Path Names:  the &PathVariable; Build Variable Function</title>
+
+        <para>
+
+        &SCons; supports a &PathVariable; function
+        to make it easy to create a build variable
+        to control an expected path name.
+        If, for example, you need to
+        define a variable in the preprocessor
+        that controls the location of a
+        configuration file:
+
+        </para>
+
+        <programlisting>
+             vars = Variables('custom.py')
+             vars.Add(PathVariable('CONFIG',
+                                 'Path to configuration file',
+                                 '/etc/my_config'))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'CONFIG_FILE' : '"$CONFIG"'})
+             env.Program('foo.c')
+        </programlisting>
+
+        <para>
+
+        This then allows the user to
+        override the &CONFIG; build variable
+        on the command line as necessary:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q foo.o</userinput>
+          cc -o foo.o -c -DCONFIG_FILE="/etc/my_config" foo.c
+          % <userinput>scons -Q CONFIG=/usr/local/etc/other_config foo.o</userinput>
+          scons: `foo.o' is up to date.
+        </screen>
+
+        <para>
+
+        By default, &PathVariable; checks to make sure
+        that the specified path exists and generates an error if it
+        doesn't:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q CONFIG=/does/not/exist foo.o</userinput>
+          
+          scons: *** Path for option CONFIG does not exist: /does/not/exist
+          File "/home/my/project/SConstruct", line 6, in ?
+        </screen>
+
+        <para>
+
+        &PathVariable; provides a number of methods
+        that you can use to change this behavior.
+        If you want to ensure that any specified paths are,
+        in fact, files and not directories,
+        use the &PathVariable_PathIsFile; method:
+
+        </para>
+
+        <programlisting>
+             vars = Variables('custom.py')
+             vars.Add(PathVariable('CONFIG',
+                                 'Path to configuration file',
+                                 '/etc/my_config',
+                                 PathVariable.PathIsFile))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'CONFIG_FILE' : '"$CONFIG"'})
+             env.Program('foo.c')
+        </programlisting>
+
+        <para>
+
+        Conversely, to ensure that any specified paths are
+        directories and not files,
+        use the &PathVariable_PathIsDir; method:
+
+        </para>
+
+        <programlisting>
+             vars = Variables('custom.py')
+             vars.Add(PathVariable('DBDIR',
+                                 'Path to database directory',
+                                 '/var/my_dbdir',
+                                 PathVariable.PathIsDir))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'DBDIR' : '"$DBDIR"'})
+             env.Program('foo.c')
+        </programlisting>
+
+        <para>
+
+        If you want to make sure that any specified paths
+        are directories,
+        and you would like the directory created
+        if it doesn't already exist,
+        use the &PathVariable_PathIsDirCreate; method:
+
+        </para>
+
+        <programlisting>
+             vars = Variables('custom.py')
+             vars.Add(PathVariable('DBDIR',
+                                 'Path to database directory',
+                                 '/var/my_dbdir',
+                                 PathVariable.PathIsDirCreate))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'DBDIR' : '"$DBDIR"'})
+             env.Program('foo.c')
+        </programlisting>
+
+        <para>
+
+        Lastly, if you don't care whether the path exists,
+        is a file, or a directory,
+        use the &PathVariable_PathAccept; method
+        to accept any path that the user supplies:
+
+        </para>
+
+        <programlisting>
+             vars = Variables('custom.py')
+             vars.Add(PathVariable('OUTPUT',
+                                 'Path to output file or directory',
+                                 None,
+                                 PathVariable.PathAccept))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'OUTPUT' : '"$OUTPUT"'})
+             env.Program('foo.c')
+        </programlisting>
+
+      </section>
+
+      <section>
+      <title>Enabled/Disabled Path Names: the &PackageVariable; Build Variable Function</title>
+
+        <para>
+
+        Sometimes you want to give users
+        even more control over a path name variable,
+        allowing them to explicitly enable or
+        disable the path name
+        by using <literal>yes</literal> or <literal>no</literal> keywords,
+        in addition to allow them
+        to supply an explicit path name.
+        &SCons; supports the &PackageVariable;
+        function to support this:
+
+        </para>
+
+        <programlisting>
+             vars = Variables('custom.py')
+             vars.Add(PackageVariable('PACKAGE',
+                                    'Location package',
+                                    '/opt/location'))
+             env = Environment(variables = vars,
+                               CPPDEFINES={'PACKAGE' : '"$PACKAGE"'})
+             env.Program('foo.c')
+        </programlisting>
+
+        <para>
+
+        When the &SConscript; file uses the &PackageVariable; funciton,
+        user can now still use the default
+        or supply an overriding path name,
+        but can now explicitly set the
+        specified variable to a value
+        that indicates the package should be enabled
+        (in which case the default should be used)
+        or disabled:
+
+        </para>
+
+        <screen>
+          % <userinput>scons -Q foo.o</userinput>
+          cc -o foo.o -c -DPACKAGE="/opt/location" foo.c
+          % <userinput>scons -Q PACKAGE=/usr/local/location foo.o</userinput>
+          scons: `foo.o' is up to date.
+          % <userinput>scons -Q PACKAGE=yes foo.o</userinput>
+          scons: `foo.o' is up to date.
+          % <userinput>scons -Q PACKAGE=no foo.o</userinput>
+          scons: `foo.o' is up to date.
+        </screen>
+
+      </section>
+
+    </section>
+
+    <section>
+    <title>Adding Multiple Command-Line Build Variables at Once</title>
+
+      <para>
+
+      Lastly, &SCons; provides a way to add
+      multiple build variables to a &Variables; object at once.
+      Instead of having to call the &Add; method
+      multiple times,
+      you can call the &AddVariables;
+      method with a list of build variables
+      to be added to the object.
+      Each build variable is specified
+      as either a tuple of arguments,
+      just like you'd pass to the &Add; method itself,
+      or as a call to one of the pre-defined
+      functions for pre-packaged command-line build variables.
+      in any order:
+
+      </para>
+
+      <programlisting>
+          vars = Variables()
+          vars.AddVariables(
+              ('RELEASE', 'Set to 1 to build for release', 0),
+              ('CONFIG', 'Configuration file', '/etc/my_config'),
+              BoolVariable('warnings', 'compilation with -Wall and similiar', 1),
+              EnumVariable('debug', 'debug output and symbols', 'no',
+                         allowed_values=('yes', 'no', 'full'),
+                         map={}, ignorecase=0),  # case sensitive
+              ListVariable('shared',
+                         'libraries to build as shared libraries',
+                         'all',
+                         names = list_of_libs),
+              PackageVariable('x11',
+                            'use X11 installed here (yes = search some places)',
+                            'yes'),
+              PathVariable('qtdir', 'where the root of Qt is installed', qtdir),
+          )
+      </programlisting>
+
+      <para>
+      </para>
+
+    </section>
+
+    <section>
+    <title>Handling Unknown Command-Line Build Variables:  the &UnknownVariables; Function</title>
+
+      <para>
+
+      Users may, of course,
+      occasionally misspell variable names in their command-line settings.
+      &SCons; does not generate an error or warning
+      for any unknown variables the users specifies on the command line.
+      (This is in no small part because you may be
+      processing the arguments directly using the &ARGUMENTS; dictionary,
+      and therefore &SCons; can't know in the general case
+      whether a given "misspelled" variable is
+      really unknown and a potential problem,
+      or something that your &SConscript; file
+      will handle directly with some Python code.)
+
+      </para>
+
+      <para>
+
+      If, however, you're using a &Variables; object to
+      define a specific set of command-line build variables
+      that you expect users to be able to set,
+      you may want to provide an error
+      message or warning of your own
+      if the user supplies a variable setting
+      that is <emphasis>not</emphasis> among
+      the defined list of variable names known to the &Variables; object.
+      You can do this by calling the &UnknownVariables;
+      method of the &Variables; object:
+
+      </para>
+
+      <programlisting>
+           vars = Variables(None)
+           vars.Add('RELEASE', 'Set to 1 to build for release', 0)
+           env = Environment(variables = vars,
+                             CPPDEFINES={'RELEASE_BUILD' : '${RELEASE}'})
+           unknown = vars.UnknownVariables()
+           if unknown:
+               print "Unknown variables:", unknown.keys()
+               Exit(1)
+           env.Program('foo.c')
+      </programlisting>
+
+      <para>
+
+      The &UnknownVariables; method returns a dictionary
+      containing the keywords and values
+      of any variables the user specified on the command line
+      that are <emphasis>not</emphasis>
+      among the variables known to the &Variables; object
+      (from having been specified using
+      the &Variables; object's&Add; method).
+      In the examble above,
+      we check for whether the dictionary
+      returned by the &UnknownVariables; is non-empty,
+      and if so print the Python list
+      containing the names of the unknwown variables
+      and then call the &Exit; function
+      to terminate &SCons;:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q NOT_KNOWN=foo</userinput>
+        Unknown variables: ['NOT_KNOWN']
+      </screen>
+
+      <para>
+
+      Of course, you can process the items in the
+      dictionary returned by the &UnknownVariables; function
+      in any way appropriate to your build configuration,
+      including just printing a warning message
+      but not exiting,
+      logging an error somewhere,
+      etc.
+
+      </para>
+
+      <para>
+
+      Note that you must delay the call of &UnknownVariables;
+      until after you have applied the &Variables; object
+      to a construction environment
+      with the <literal>variables=</literal>
+      keyword argument of an &Environment; call.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <section id="sect-command-line-targets">
+  <title>Command-Line Targets</title>
+
+    <section>
+    <title>Fetching Command-Line Targets: the &COMMAND_LINE_TARGETS; Variable</title>
+
+      <para>
+
+      &SCons; supports a &COMMAND_LINE_TARGETS; variable
+      that lets you fetch the list of targets that the
+      user specified on the command line.
+      You can use the targets to manipulate the
+      build in any way you wish.
+      As a simple example,
+      suppose that you want to print a reminder
+      to the user whenever a specific program is built.
+      You can do this by checking for the
+      target in the &COMMAND_LINE_TARGETS; list:
+
+      </para>
+
+      <programlisting>
+        if 'bar' in COMMAND_LINE_TARGETS:
+            print "Don't forget to copy `bar' to the archive!"
+        Default(Program('foo.c'))
+        Program('bar.c')
+      </programlisting>
+
+      <para>
+
+      Then, running &SCons; with the default target
+      works as it always does,
+      but explicity specifying the &bar; target
+      on the command line generates the warning message:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q</userinput>
+        cc -o foo.o -c foo.c
+        cc -o foo foo.o
+        % <userinput>scons -Q bar</userinput>
+        Don't forget to copy `bar' to the archive!
+        cc -o bar.o -c bar.c
+        cc -o bar bar.o
+      </screen>
+
+      <para>
+
+      Another practical use for the &COMMAND_LINE_TARGETS; variable
+      might be to speed up a build
+      by only reading certain subsidiary &SConscript;
+      files if a specific target is requested.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Controlling the Default Targets:  the &Default; Function</title>
+
+      <para>
+
+      One of the most basic things you can control
+      is which targets &SCons; will build by default--that is,
+      when there are no targets specified on the command line.
+      As mentioned previously,
+      &SCons; will normally build every target
+      in or below the current directory
+      by default--that is, when you don't
+      explicitly specify one or more targets
+      on the command line.
+      Sometimes, however, you may want
+      to specify explicitly that only
+      certain programs, or programs in certain directories,
+      should be built by default.
+      You do this with the &Default; function:
+
+      </para>
+
+      <programlisting>
+         env = Environment()
+         hello = env.Program('hello.c')
+         env.Program('goodbye.c')
+         Default(hello)
+      </programlisting>
+
+      <para>
+
+      This &SConstruct; file knows how to build two programs,
+      &hello; and &goodbye;,
+      but only builds the
+      &hello; program by default:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+         % <userinput>scons -Q</userinput>
+         scons: `hello' is up to date.
+         % <userinput>scons -Q goodbye</userinput>
+         cc -o goodbye.o -c goodbye.c
+         cc -o goodbye goodbye.o
+      </screen>
+
+      <para>
+
+      Note that, even when you use the &Default;
+      function in your &SConstruct; file,
+      you can still explicitly specify the current directory
+      (<literal>.</literal>) on the command line
+      to tell &SCons; to build
+      everything in (or below) the current directory:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q .</userinput>
+         cc -o goodbye.o -c goodbye.c
+         cc -o goodbye goodbye.o
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+      </screen>
+
+      <para>
+
+      You can also call the &Default;
+      function more than once,
+      in which case each call
+      adds to the list of targets to be built by default:
+
+      </para>
+
+      <programlisting>
+         env = Environment()
+         prog1 = env.Program('prog1.c')
+         Default(prog1)
+         prog2 = env.Program('prog2.c')
+         prog3 = env.Program('prog3.c')
+         Default(prog3)
+      </programlisting>
+
+      <para>
+
+      Or you can specify more than one target
+      in a single call to the &Default; function:
+
+      </para>
+
+      <programlisting>
+         env = Environment()
+         prog1 = env.Program('prog1.c')
+         prog2 = env.Program('prog2.c')
+         prog3 = env.Program('prog3.c')
+         Default(prog1, prog3)
+      </programlisting>
+
+      <para>
+
+      Either of these last two examples
+      will build only the
+      <application>prog1</application>
+      and
+      <application>prog3</application>
+      programs by default:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         cc -o prog1.o -c prog1.c
+         cc -o prog1 prog1.o
+         cc -o prog3.o -c prog3.c
+         cc -o prog3 prog3.o
+         % <userinput>scons -Q .</userinput>
+         cc -o prog2.o -c prog2.c
+         cc -o prog2 prog2.o
+      </screen>
+
+      <para>
+
+      You can list a directory as
+      an argument to &Default;:
+
+      </para>
+
+      <programlisting>
+         env = Environment()
+         env.Program(['prog1/main.c', 'prog1/foo.c'])
+         env.Program(['prog2/main.c', 'prog2/bar.c'])
+         Default('prog1')
+      </programlisting>
+
+      <para>
+
+      In which case only the target(s) in that
+      directory will be built by default:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         cc -o prog1/foo.o -c prog1/foo.c
+         cc -o prog1/main.o -c prog1/main.c
+         cc -o prog1/main prog1/main.o prog1/foo.o
+         % <userinput>scons -Q</userinput>
+         scons: `prog1' is up to date.
+         % <userinput>scons -Q .</userinput>
+         cc -o prog2/bar.o -c prog2/bar.c
+         cc -o prog2/main.o -c prog2/main.c
+         cc -o prog2/main prog2/main.o prog2/bar.o
+      </screen>
+
+      <para>
+
+      Lastly, if for some reason you don't want
+      any targets built by default,
+      you can use the Python <literal>None</literal>
+      variable:
+
+      </para>
+
+      <programlisting>
+         env = Environment()
+         prog1 = env.Program('prog1.c')
+         prog2 = env.Program('prog2.c')
+         Default(None)
+      </programlisting>
+
+      <para>
+
+      Which would produce build output like:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         scons: *** No targets specified and no Default() targets found.  Stop.
+         % <userinput>scons -Q .</userinput>
+         cc -o prog1.o -c prog1.c
+         cc -o prog1 prog1.o
+         cc -o prog2.o -c prog2.c
+         cc -o prog2 prog2.o
+      </screen>
+
+      <section>
+      <title>Fetching the List of Default Targets: the &DEFAULT_TARGETS; Variable</title>
+
+        <para>
+
+        &SCons; supports a &DEFAULT_TARGETS; variable
+        that lets you get at the current list of default targets.
+        The &DEFAULT_TARGETS variable has
+        two important differences from the &COMMAND_LINE_TARGETS; variable.
+        First, the &DEFAULT_TARGETS; variable is a list of
+        internal &SCons; nodes,
+        so you need to convert the list elements to strings
+        if you want to print them or look for a specific target name.
+        Fortunately, you can do this easily
+        by using the Python <function>map</function> function
+        to run the list through <function>str</function>:
+
+        </para>
+
+        <programlisting>
+           prog1 = Program('prog1.c')
+           Default(prog1)
+           print "DEFAULT_TARGETS is", map(str, DEFAULT_TARGETS)
+        </programlisting>
+
+        <para>
+
+        (Keep in mind that all of the manipulation of the
+        &DEFAULT_TARGETS; list takes place during the
+        first phase when &SCons; is reading up the &SConscript; files,
+        which is obvious if
+        we leave off the <literal>-Q</literal> flag when we run &SCons;:)
+
+        </para>
+
+        <screen>
+           % <userinput>scons</userinput>
+           scons: Reading SConscript files ...
+           DEFAULT_TARGETS is ['prog1']
+           scons: done reading SConscript files.
+           scons: Building targets ...
+           cc -o prog1.o -c prog1.c
+           cc -o prog1 prog1.o
+           scons: done building targets.
+        </screen>
+
+        <para>
+
+        Second,
+        the contents of the &DEFAULT_TARGETS; list change
+        in response to calls to the &Default;: function,
+        as you can see from the following &SConstruct; file:
+
+        </para>
+
+        <programlisting>
+           prog1 = Program('prog1.c')
+           Default(prog1)
+           print "DEFAULT_TARGETS is now", map(str, DEFAULT_TARGETS)
+           prog2 = Program('prog2.c')
+           Default(prog2)
+           print "DEFAULT_TARGETS is now", map(str, DEFAULT_TARGETS)
+        </programlisting>
+
+        <para>
+
+        Which yields the output:
+
+        </para>
+
+        <screen>
+           % <userinput>scons</userinput>
+           scons: Reading SConscript files ...
+           DEFAULT_TARGETS is now ['prog1']
+           DEFAULT_TARGETS is now ['prog1', 'prog2']
+           scons: done reading SConscript files.
+           scons: Building targets ...
+           cc -o prog1.o -c prog1.c
+           cc -o prog1 prog1.o
+           cc -o prog2.o -c prog2.c
+           cc -o prog2 prog2.o
+           scons: done building targets.
+        </screen>
+
+        <para>
+
+        In practice, this simply means that you
+        need to pay attention to the order in
+        which you call the &Default; function
+        and refer to the &DEFAULT_TARGETS; list,
+        to make sure that you don't examine the
+        list before you've added the default targets
+        you expect to find in it.
+
+        </para>
+
+      </section>
+
+    </section>
+
+    <section>
+    <title>Fetching the List of Build Targets, Regardless of Origin: the &BUILD_TARGETS; Variable</title>
+
+      <para>
+
+      We've already been introduced to the
+      &COMMAND_LINE_TARGETS; variable,
+      which contains a list of targets specified on the command line,
+      and the &DEFAULT_TARGETS; variable,
+      which contains a list of targets specified
+      via calls to the &Default; method or function.
+      Sometimes, however,
+      you want a list of whatever targets
+      &SCons; will try to build,
+      regardless of whether the targets came from the
+      command line or a &Default; call.
+      You could code this up by hand, as follows:
+
+      </para>
+
+      <programlisting>
+        if COMMAND_LINE_TARGETS:
+            targets = COMMAND_LINE_TARGETS
+        else:
+            targets = DEFAULT_TARGETS
+      </programlisting>
+
+      <para>
+
+      &SCons;, however, provides a convenient
+      &BUILD_TARGETS; variable
+      that eliminates the need for this by-hand manipulation.
+      Essentially, the &BUILD_TARGETS; variable
+      contains a list of the command-line targets,
+      if any were specified,
+      and if no command-line targets were specified,
+      it contains a list of the targets specified
+      via the &Default; method or function.
+
+      </para>
+
+      <para>
+
+      Because &BUILD_TARGETS; may contain a list of &SCons; nodes,
+      you must convert the list elements to strings
+      if you want to print them or look for a specific target name,
+      just like the &DEFAULT_TARGETS; list:
+
+      </para>
+
+      <programlisting>
+        prog1 = Program('prog1.c')
+        Program('prog2.c')
+        Default(prog1)
+        print "BUILD_TARGETS is", map(str, BUILD_TARGETS)
+      </programlisting>
+
+      <para>
+
+      Notice how the value of &BUILD_TARGETS;
+      changes depending on whether a target is
+      specified on the command line:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q</userinput>
+        BUILD_TARGETS is ['prog1']
+        cc -o prog1.o -c prog1.c
+        cc -o prog1 prog1.o
+        % <userinput>scons -Q prog2</userinput>
+        BUILD_TARGETS is ['prog2']
+        cc -o prog2.o -c prog2.c
+        cc -o prog2 prog2.o
+        % <userinput>scons -Q -c .</userinput>
+        BUILD_TARGETS is ['.']
+        Removed prog1.o
+        Removed prog1
+        Removed prog2.o
+        Removed prog2
+      </screen>
+
+    </section>
+
+  </section>
diff --git a/doc/user/cons.pl b/doc/user/cons.pl
new file mode 100644
index 0000000..8afbfec
--- /dev/null
+++ b/doc/user/cons.pl
@@ -0,0 +1,720 @@
+=head1 Introduction
+
+B<Cons> is a system for constructing, primarily, software, but is quite
+different from previous software construction systems. Cons was designed
+from the ground up to deal easily with the construction of software spread
+over multiple source directories. Cons makes it easy to create build scripts
+that are simple, understandable and maintainable. Cons ensures that complex
+software is easily and accurately reproducible.
+
+Cons uses a number of techniques to accomplish all of this. Construction
+scripts are just Perl scripts, making them both easy to comprehend and very
+flexible. Global scoping of variables is replaced with an import/export
+mechanism for sharing information between scripts, significantly improving
+the readability and maintainability of each script. B<Construction
+environments> are introduced: these are Perl objects that capture the
+information required for controlling the build process. Multiple
+environments are used when different semantics are required for generating
+products in the build tree. Cons implements automatic dependency analysis
+and uses this to globally sequence the entire build. Variant builds are
+easily produced from a single source tree. Intelligent build subsetting is
+possible, when working on localized changes. Overrides can be setup to
+easily override build instructions without modifying any scripts. MD5
+cryptographic B<signatures> are associated with derived files, and are used
+to accurately determine whether a given file needs to be rebuilt.
+
+While offering all of the above, and more, Cons remains simple and easy to
+use. This will, hopefully, become clear as you read the remainder of this
+document.
+
+
+
+=head2 Automatic global build sequencing
+
+Because Cons does full and accurate dependency analysis, and does this
+globally, for the entire build, Cons is able to use this information to take
+full control of the B<sequencing> of the build. This sequencing is evident
+in the above examples, and is equivalent to what you would expect for make,
+given a full set of dependencies. With Cons, this extends trivially to
+larger, multi-directory builds. As a result, all of the complexity involved
+in making sure that a build is organized correctly--including multi-pass
+hierarchical builds--is eliminated. We'll discuss this further in the next
+sections.
+
+
+
+=head1 A Model for sharing files
+
+
+=head2 Some simple conventions
+
+In any complex software system, a method for sharing build products needs to
+be established. We propose a simple set of conventions which are trivial to
+implement with Cons, but very effective.
+
+The basic rule is to require that all build products which need to be shared
+between directories are shared via an intermediate directory. We have
+typically called this F<export>, and, in a C environment, provided
+conventional sub-directories of this directory, such as F<include>, F<lib>,
+F<bin>, etc.
+
+These directories are defined by the top-level F<Construct> file. A simple
+F<Construct> file for a B<Hello, World!> application, organized using
+multiple directories, might look like this:
+
+  # Construct file for Hello, World!
+
+  # Where to put all our shared products.
+  $EXPORT = '#export';
+
+  Export qw( CONS INCLUDE LIB BIN );
+
+  # Standard directories for sharing products.
+  $INCLUDE = "$EXPORT/include";
+  $LIB = "$EXPORT/lib";
+  $BIN = "$EXPORT/bin";
+
+  # A standard construction environment.
+  $CONS = new cons (
+	CPPPATH => $INCLUDE,	# Include path for C Compilations
+	LIBPATH => $LIB,	# Library path for linking programs
+	LIBS => '-lworld',	# List of standard libraries
+  );
+
+  Build qw(
+	hello/Conscript
+	world/Conscript
+  );
+
+The F<world> directory's F<Conscript> file looks like this:
+
+  # Conscript file for directory world
+  Import qw( CONS INCLUDE LIB );
+
+  # Install the products of this directory
+  Install $CONS $LIB, 'libworld.a';
+  Install $CONS $INCLUDE, 'world.h';
+
+  # Internal products
+  Library $CONS 'libworld.a', 'world.c';
+
+and the F<hello> directory's F<Conscript> file looks like this:
+
+  # Conscript file for directory hello
+  Import qw( CONS BIN );
+
+  # Exported products
+  Install $CONS $BIN, 'hello';
+
+  # Internal products
+  Program $CONS 'hello', 'hello.c';
+
+To construct a B<Hello, World!> program with this directory structure, go to
+the top-level directory, and invoke C<cons> with the appropriate
+arguments. In the following example, we tell Cons to build the directory
+F<export>. To build a directory, Cons recursively builds all known products
+within that directory (only if they need rebuilding, of course). If any of
+those products depend upon other products in other directories, then those
+will be built, too.
+
+  % cons export
+  Install world/world.h as export/include/world.h
+  cc -Iexport/include -c hello/hello.c -o hello/hello.o
+  cc -Iexport/include -c world/world.c -o world/world.o
+  ar r world/libworld.a world/world.o
+  ar: creating world/libworld.a
+  ranlib world/libworld.a
+  Install world/libworld.a as export/lib/libworld.a
+  cc -o hello/hello hello/hello.o -Lexport/lib -lworld
+  Install hello/hello as export/bin/hello
+
+
+=head2 Clean, understandable, location-independent scripts
+
+You'll note that the two F<Conscript> files are very clean and
+to-the-point. They simply specify products of the directory and how to build
+those products. The build instructions are minimal: they specify which
+construction environment to use, the name of the product, and the name of
+the inputs. Note also that the scripts are location-independent: if you wish
+to reorganize your source tree, you are free to do so: you only have to
+change the F<Construct> file (in this example), to specify the new locations
+of the F<Conscript> files. The use of an export tree makes this goal easy.
+
+Note, too, how Cons takes care of little details for you. All the F<export>
+directories, for example, were made automatically. And the installed files
+were really hard-linked into the respective export directories, to save
+space and time. This attention to detail saves considerable work, and makes
+it even easier to produce simple, maintainable scripts.
+
+
+
+=head1 Signatures
+
+Cons uses file B<signatures> to decide if a derived file is out-of-date
+and needs rebuilding.  In essence, if the contents of a file change,
+or the manner in which the file is built changes, the file's signature
+changes as well.  This allows Cons to decide with certainty when a file
+needs rebuilding, because Cons can detect, quickly and reliably, whether
+any of its dependency files have been changed.
+
+
+=head2 MD5 content and build signatures
+
+Cons uses the B<MD5> (B<Message Digest 5>) algorithm to compute file
+signatures.  The MD5 algorithm computes a strong cryptographic checksum
+for any given input string.  Cons can, based on configuration, use two
+different MD5 signatures for a given file:
+
+The B<content signature> of a file is an MD5 checksum of the file's
+contents.  Consequently, when the contents of a file change, its content
+signature changes as well.
+
+The B<build signature> of a file is a combined MD5 checksum of:
+
+=over 4
+
+the signatures of all the input files used to build the file
+
+the signatures of all dependency files discovered by source scanners
+(for example, C<.h> files)
+
+the signatures of all dependency files specified explicitly via the
+C<Depends> method)
+
+the command-line string used to build the file
+
+=back
+
+The build signature is, in effect, a digest of all the dependency
+information for the specified file.  Consequently, a file's build
+signature changes whenever any part of its dependency information
+changes: a new file is added, the contents of a file on which it depends
+change, there's a change to the command line used to build the file (or
+any of its dependency files), etc.
+
+For example, in the previous section, the build signature of the
+F<world.o> file will include:
+
+=over 4
+
+the signature of the F<world.c> file
+
+the signatures of any header files that Cons detects are included,
+directly or indirectly, by F<world.c>
+
+the text of the actual command line was used to generate F<world.o>
+
+=back
+
+Similarly, the build signature of the F<libworld.a> file will include
+all the signatures of its constituents (and hence, transitively, the
+signatures of B<their> constituents), as well as the command line that
+created the file.
+
+Note that there is no need for a derived file to depend upon any
+particular F<Construct> or F<Conscript> file.  If changes to these files
+affect a file, then this will be automatically reflected in its build
+signature, since relevant parts of the command line are included in the
+signature. Unrelated F<Construct> or F<Conscript> changes will have no
+effect.
+
+
+=head2 Storing signatures in .consign files
+
+Before Cons exits, it stores the calculated signatures for all of the
+files it built or examined in F<.consign> files, one per directory.
+Cons uses this stored information on later invocations to decide if
+derived files need to be rebuilt.
+
+After the previous example was compiled, the F<.consign> file in the
+F<build/peach/world> directory looked like this:
+
+  world.h:985533370 - d181712f2fdc07c1f05d97b16bfad904
+  world.o:985533372 2a0f71e0766927c0532977b0d2158981
+  world.c:985533370 - c712f77189307907f4189b5a7ab62ff3
+  libworld.a:985533374 69e568fc5241d7d25be86d581e1fb6aa
+
+After the file name and colon, the first number is a timestamp of the
+file's modification time (on UNIX systems, this is typically the number
+of seconds since January 1st, 1970).  The second value is the build
+signature of the file (or ``-'' in the case of files with no build
+signature--that is, source files).  The third value, if any, is the
+content signature of the file.
+
+
+=head2 Using build signatures to decide when to rebuild files
+
+When Cons is deciding whether to build or rebuild a derived file, it
+first computes the file's current build signature.  If the file doesn't
+exist, it must obviously be built.
+
+If, however, the file already exists, Cons next compares the
+modification timestamp of the file against the timestamp value in
+the F<.consign> file.  If the timestamps match, Cons compares the
+newly-computed build signature against the build signature in the
+F<.consign> file.  If the timestamps do not match or the build
+signatures do not match, the derived file is rebuilt.
+
+After the file is built or rebuilt, Cons arranges to store the
+newly-computed build signature in the F<.consign> file when it exits.
+
+
+=head2 Signature example
+
+The use of these signatures is an extremely simple, efficient, and
+effective method of improving--dramatically--the reproducibility of a
+system.
+
+We'll demonstrate this with a simple example:
+
+  # Simple "Hello, World!" Construct file
+  $CFLAGS = '-g' if $ARG{DEBUG} eq 'on';
+  $CONS = new cons(CFLAGS => $CFLAGS);
+  Program $CONS 'hello', 'hello.c';
+
+Notice how Cons recompiles at the appropriate times:
+
+  % cons hello
+  cc -c hello.c -o hello.o
+  cc -o hello hello.o
+  % cons hello
+  cons: "hello" is up-to-date.
+  % cons DEBUG=on hello
+  cc -g -c hello.c -o hello.o
+  cc -o hello hello.o
+  % cons DEBUG=on hello
+  cons: "hello" is up-to-date.
+  % cons hello
+  cc -c hello.c -o hello.o
+  cc -o hello hello.o
+
+
+=head2 Source-file signature configuration
+
+Cons provides a C<SourceSignature> method that allows you to configure
+how the signature should be calculated for any source file when its
+signature is being used to decide if a dependent file is up-to-date.
+The arguments to the C<SourceSignature> method consist of one or more
+pairs of strings:
+
+  SourceSignature 'auto/*.c' => 'content',
+		  '*' => 'stored-content';
+
+The first string in each pair is a pattern to match against derived file
+path names. The pattern is a file-globbing pattern, not a Perl regular
+expression; the pattern <*.l> will match all Lex source files.  The C<*>
+wildcard will match across directory separators; the pattern C<foo/*.c>
+would match all C source files in any subdirectory underneath the C<foo>
+subdirectory.
+
+The second string in each pair contains one of the following keywords to
+specify how signatures should be calculated for source files that match
+the pattern.  The available keywords are:
+
+=over 4
+
+=item content
+
+Use the content signature of the source file when calculating signatures
+of files that depend on it.  This guarantees correct calculation of the
+file's signature for all builds, by telling Cons to read the contents of
+a source file to calculate its content signature each time it is run.
+
+=item stored-content
+
+Use the source file's content signature as stored in the F<.consign>
+file, provided the file's timestamp matches the cached timestamp value
+in the F<.consign> file.  This optimizes performance, with the slight
+risk of an incorrect build if a source file's contents have been changed
+so quickly after its previous update that the timestamp still matches
+the stored timestamp in the F<.consign> file even though the contents
+have changed.
+
+=back
+
+The Cons default behavior of always calculating a source file's
+signature from the file's contents is equivalent to specifying:
+
+  SourceSignature '*' => 'content';
+
+The C<*> will match all source files.  The C<content> keyword
+specifies that Cons will read the contents of a source file to calculate
+its signature each time it is run.
+
+A useful global performance optimization is:
+
+  SourceSignature '*' => 'stored-content';
+
+This specifies that Cons will use pre-computed content signatures
+from F<.consign> files, when available, rather than re-calculating a
+signature from the the source file's contents each time Cons is run.  In
+practice, this is safe for most build situations, and only a problem
+when source files are changed automatically (by scripts, for example).
+The Cons default, however, errs on the side of guaranteeing a correct
+build in all situations.
+
+Cons tries to match source file path names against the patterns in the
+order they are specified in the C<SourceSignature> arguments:
+
+  SourceSignature '/usr/repository/objects/*' => 'stored-content',
+		  '/usr/repository/*' => 'content',
+		  '*.y' => 'content',
+		  '*' => 'stored-content';
+
+In this example, all source files under the F</usr/repository/objects>
+directory will use F<.consign> file content signatures, source files
+anywhere else underneath F</usr/repository> will not use F<.consign>
+signature values, all Yacc source files (C<*.y>) anywhere else will not
+use F<.consign> signature values, and any other source file will use
+F<.consign> signature values.
+
+
+=head2 Derived-file signature configuration
+
+Cons provides a C<SIGNATURE> construction variable that allows you to
+configure how signatures are calculated for any derived file when its
+signature is being used to decide if a dependent file is up-to-date.
+The value of the C<SIGNATURE> construction variable is a Perl array
+reference that holds one or more pairs of strings, like the arguments to
+the C<SourceSignature> method.
+
+The first string in each pair is a pattern to match against derived file
+path names. The pattern is a file-globbing pattern, not a Perl regular
+expression; the pattern `*.obj' will match all (Win32) object files.
+The C<*> wildcard will match across directory separators; the pattern
+`foo/*.a' would match all (UNIX) library archives in any subdirectory
+underneath the foo subdirectory.
+
+The second string in each pair contains one of the following keywords
+to specify how signatures should be calculated for derived files that
+match the pattern.  The available keywords are the same as for the
+C<SourceSignature> method, with an additional keyword:
+
+=over 4
+
+=item build
+
+Use the build signature of the derived file when calculating signatures
+of files that depend on it.  This guarantees correct builds by forcing
+Cons to rebuild any and all files that depend on the derived file.
+
+=item content
+
+Use the content signature of the derived file when calculating signatures
+of files that depend on it.  This guarantees correct calculation of the
+file's signature for all builds, by telling Cons to read the contents of
+a derived file to calculate its content signature each time it is run.
+
+=item stored-content
+
+Use the derived file's content signature as stored in the F<.consign>
+file, provided the file's timestamp matches the cached timestamp value
+in the F<.consign> file.  This optimizes performance, with the slight
+risk of an incorrect build if a derived file's contents have been
+changed so quickly after a Cons build that the file's timestamp still
+matches the stored timestamp in the F<.consign> file.
+
+=back
+
+The Cons default behavior (as previously described) for using
+derived-file signatures is equivalent to:
+
+  $env = new cons(SIGNATURE => ['*' => 'build']);
+
+The C<*> will match all derived files.  The C<build> keyword specifies
+that all derived files' build signatures will be used when calculating
+whether a dependent file is up-to-date.
+
+A useful alternative default C<SIGNATURE> configuration for many sites:
+
+  $env = new cons(SIGNATURE => ['*' => 'content']);
+
+In this configuration, derived files have their signatures calculated
+from the file contents.  This adds slightly to Cons' workload, but has
+the useful effect of "stopping" further rebuilds if a derived file is
+rebuilt to exactly the same file contents as before, which usually
+outweighs the additional computation Cons must perform.
+
+For example, changing a comment in a C file and recompiling should
+generate the exact same object file (assuming the compiler doesn't
+insert a timestamp in the object file's header).  In that case,
+specifying C<content> or C<stored-content> for the signature calculation
+will cause Cons to recognize that the object file did not actually
+change as a result of being rebuilt, and libraries or programs that
+include the object file will not be rebuilt.  When C<build> is
+specified, however, Cons will only "know" that the object file was
+rebuilt, and proceed to rebuild any additional files that include the
+object file.
+
+Note that Cons tries to match derived file path names against the
+patterns in the order they are specified in the C<SIGNATURE> array
+reference:
+
+  $env = new cons(SIGNATURE => ['foo/*.o' => 'build',
+				'*.o' => 'content',
+				'*.a' => 'stored-content',
+				'*' => 'content']);
+
+In this example, all object files underneath the F<foo> subdirectory
+will use build signatures, all other object files (including object
+files underneath other subdirectories!) will use F<.consign> file
+content signatures, libraries will use F<.consign> file build
+signatures, and all other derived files will use content signatures.
+
+
+=head2 Debugging signature calculation
+
+Cons provides a C<-S> option that can be used to specify what internal
+Perl package Cons should use to calculate signatures.  The default Cons
+behavior is equivalent to specifying C<-S md5> on the command line.
+
+The only other package (currently) available is an C<md5::debug>
+package that prints out detailed information about the MD5 signature
+calculations performed by Cons:
+
+  % cons -S md5::debug hello
+  sig::md5::srcsig(hello.c)
+          => |52d891204c62fe93ecb95281e1571938|
+  sig::md5::collect(52d891204c62fe93ecb95281e1571938)
+          => |fb0660af4002c40461a2f01fbb5ffd03|
+  sig::md5::collect(52d891204c62fe93ecb95281e1571938,
+                    fb0660af4002c40461a2f01fbb5ffd03,
+                    cc   -c %< -o %>)
+          => |f7128da6c3fe3c377dc22ade70647b39|
+  sig::md5::current(||
+                 eq |f7128da6c3fe3c377dc22ade70647b39|)
+  cc -c hello.c -o hello.o
+  sig::md5::collect()
+          => |d41d8cd98f00b204e9800998ecf8427e|
+  sig::md5::collect(f7128da6c3fe3c377dc22ade70647b39,
+                    d41d8cd98f00b204e9800998ecf8427e,
+                    cc  -o %> %<  )
+          => |a0bdce7fd09e0350e7efbbdb043a00b0|
+  sig::md5::current(||
+                 eq |a0bdce7fd09e0350e7efbbdb043a00b0|)
+  cc -o hello, hello.o
+
+
+
+
+
+
+
+=head1 Temporary overrides
+
+Cons provides a very simple mechanism for overriding aspects of a build. The
+essence is that you write an override file containing one or more
+C<Override> commands, and you specify this on the command line, when you run
+C<cons>:
+
+  % cons -o over export
+
+will build the F<export> directory, with all derived files subject to the
+overrides present in the F<over> file. If you leave out the C<-o> option,
+then everything necessary to remove all overrides will be rebuilt.
+
+
+=head2 Overriding environment variables
+
+The override file can contain two types of overrides. The first is incoming
+environment variables. These are normally accessible by the F<Construct>
+file from the C<%ENV> hash variable. These can trivially be overridden in
+the override file by setting the appropriate elements of C<%ENV> (these
+could also be overridden in the user's environment, of course).
+
+
+=head2 The Override command
+
+The second type of override is accomplished with the C<Override> command,
+which looks like this:
+
+  Override <regexp>, <var1> => <value1>, <var2> => <value2>, ...;
+
+The regular expression I<regexp> is matched against every derived file that
+is a candidate for the build. If the derived file matches, then the
+variable/value pairs are used to override the values in the construction
+environment associated with the derived file.
+
+Let's suppose that we have a construction environment like this:
+
+  $CONS = new cons(
+	COPT => '',
+	CDBG => '-g',
+	CFLAGS => '%COPT %CDBG',
+  );
+
+Then if we have an override file F<over> containing this command:
+
+  Override '\.o$', COPT => '-O', CDBG => '';
+
+then any C<cons> invocation with C<-o over> that creates F<.o> files via
+this environment will cause them to be compiled with C<-O >and no C<-g>. The
+override could, of course, be restricted to a single directory by the
+appropriate selection of a regular expression.
+
+Here's the original version of the Hello, World! program, built with this
+environment. Note that Cons rebuilds the appropriate pieces when the
+override is applied or removed:
+
+  % cons hello
+  cc -g -c hello.c -o hello.o
+  cc -o hello hello.o
+  % cons -o over hello
+  cc -O -c hello.c -o hello.o
+  cc -o hello hello.o
+  % cons -o over hello
+  cons: "hello" is up-to-date.
+  % cons hello
+  cc -g -c hello.c -o hello.o
+  cc -o hello hello.o
+
+It's important that the C<Override> command only be used for temporary,
+on-the-fly overrides necessary for development because the overrides are not
+platform independent and because they rely too much on intimate knowledge of
+the workings of the scripts. For temporary use, however, they are exactly
+what you want.
+
+Note that it is still useful to provide, say, the ability to create a fully
+optimized version of a system for production use--from the F<Construct> and
+F<Conscript> files. This way you can tailor the optimized system to the
+platform. Where optimizer trade-offs need to be made (particular files may
+not be compiled with full optimization, for example), then these can be
+recorded for posterity (and reproducibility) directly in the scripts.
+
+
+
+=head2 The C<Module> method
+
+The C<Module> method is a combination of the C<Program> and C<Command>
+methods. Rather than generating an executable program directly, this command
+allows you to specify your own command to actually generate a module. The
+method is invoked as follows:
+
+  Module $env <module name>, <source or object files>, <construction command>;
+
+This command is useful in instances where you wish to create, for example,
+dynamically loaded modules, or statically linked code libraries.
+
+
+
+
+=head2 The C<RuleSet> method
+
+The C<RuleSet> method returns the construction variables for building
+various components with one of the rule sets supported by Cons.  The
+currently supported rule sets are:
+
+=over 4
+
+=item msvc
+
+Rules for the Microsoft Visual C++ compiler suite.
+
+=item unix
+
+Generic rules for most UNIX-like compiler suites.
+
+=back
+
+On systems with more than one available compiler suite, this allows you
+to easily create side-by-side environments for building software with
+multiple tools:
+
+    $msvcenv = new cons(RuleSet("msvc"));
+    $cygnusenv = new cons(RuleSet("unix"));
+
+In the future, this could also be extended to other platforms that
+have different default rule sets.
+
+
+=head2 The C<DefaultRules> method
+
+The C<DefaultRules> method sets the default construction variables that
+will be returned by the C<new> method to the specified arguments:
+
+  DefaultRules(CC     => 'gcc',
+	       CFLAGS => '',
+	       CCCOM  => '%CC %CFLAGS %_IFLAGS -c %< -o %>');
+  $env = new cons();
+  # $env now contains *only* the CC, CFLAGS,
+  # and CCCOM construction variables
+
+Combined with the C<RuleSet> method, this also provides an easy way
+to set explicitly the default build environment to use some supported
+toolset other than the Cons defaults:
+
+    # use a UNIX-like tool suite (like cygwin) on Win32
+    DefaultRules(RuleSet('unix'));
+    $env = new cons();
+
+Note that the C<DefaultRules> method completely replaces the default
+construction environment with the specified arguments, it does not
+simply override the existing defaults.  To override one or more
+variables in a supported C<RuleSet>, append the variables and values:
+
+  DefaultRules(RuleSet('unix'), CFLAGS => '-O3');
+  $env1 = new cons();
+  $env2 = new cons();
+  # both $env1 and $env2 have 'unix' defaults
+  # with CFLAGS set to '-O3'
+
+
+
+
+
+
+
+
+=head2 The C<SourcePath> method
+
+The C<SourcePath> mathod returns the real source path name of a file,
+as opposed to the path name within a build directory.  It is invoked
+as follows:
+
+  $path = SourcePath <buildpath>;
+
+
+=head2 The C<ConsPath> method
+
+The C<ConsPath> method returns true if the supplied path is a derivable
+file, and returns undef (false) otherwise.
+It is invoked as follows:
+
+  $result = ConsPath <path>;
+
+
+=head2 The C<SplitPath> method
+
+The C<SplitPath> method looks up multiple path names in a string separated
+by the default path separator for the operating system (':' on UNIX
+systems, ';' on Windows NT), and returns the fully-qualified names.
+It is invoked as follows:
+
+  @paths = SplitPath <pathlist>;
+
+The C<SplitPath> method will convert  names prefixed '#' to the
+appropriate top-level build name (without the '#') and will convert
+relative names to top-level names.
+
+
+=head2 The C<DirPath> method
+
+The C<DirPath> method returns the build path name(s) of a directory or
+list of directories.  It is invoked as follows:
+
+  $cwd = DirPath <paths>;
+
+The most common use for the C<DirPath> method is:
+
+  $cwd = DirPath '.';
+
+to fetch the path to the current directory of a subsidiary F<Conscript>
+file.
+
+
+=head2 The C<FilePath> method
+
+The C<FilePath> method returns the build path name(s) of a file or
+list of files.  It is invoked as follows:
+
+  $file = FilePath <path>;
diff --git a/doc/user/copyright.in b/doc/user/copyright.in
new file mode 100644
index 0000000..341698d
--- /dev/null
+++ b/doc/user/copyright.in
@@ -0,0 +1,32 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<blockquote>
+ <para>
+
+  SCons User's Guide Copyright (c) 2004, 2005, 2006, 2007 Steven Knight
+
+ </para>
+</blockquote>
diff --git a/doc/user/copyright.xml b/doc/user/copyright.xml
new file mode 100644
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+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<blockquote>
+ <para>
+
+  SCons User's Guide Copyright (c) 2004, 2005, 2006, 2007 Steven Knight
+
+ </para>
+</blockquote>
diff --git a/doc/user/depends.in b/doc/user/depends.in
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+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  So far we've seen how &SCons; handles one-time builds.
+  But one of the main functions of a build tool like &SCons;
+  is to rebuild only what is necessary
+  when source files change--or, put another way,
+  &SCons; should <emphasis>not</emphasis>
+  waste time rebuilding things that don't need to be rebuilt.
+  You can see this at work simply by re-invoking &SCons;
+  after building our simple &hello; example:
+
+  </para>
+
+  <scons_example name="ex1">
+    <file name="SConstruct">
+    Program('hello.c')
+    </file>
+    <file name="hello.c">
+    int main() { printf("Hello, world!\n"); }
+    </file>
+  </scons_example>
+
+  <scons_output example="ex1" os="posix">
+     <scons_output_command>scons -Q</scons_output_command>
+     <scons_output_command>scons -Q</scons_output_command>
+  </scons_output>
+
+  <para>
+
+  The second time it is executed,
+  &SCons; realizes that the &hello; program
+  is up-to-date with respect to the current &hello_c; source file,
+  and avoids rebuilding it.
+  You can see this more clearly by naming
+  the &hello; program explicitly on the command line:
+
+  </para>
+
+  <scons_output example="ex1" os="posix">
+     <scons_output_command>scons -Q hello</scons_output_command>
+     <scons_output_command>scons -Q hello</scons_output_command>
+  </scons_output>
+
+  <para>
+
+  Note that &SCons; reports <literal>"...is up to date"</literal>
+  only for target files named explicitly on the command line,
+  to avoid cluttering the output.
+
+  </para>
+
+  <section>
+  <title>Deciding When an Input File Has Changed:  the &Decider; Function</title>
+
+    <para>
+
+    Another aspect of avoiding unnecessary rebuilds
+    is the fundamental build tool behavior
+    of <emphasis>rebuilding</emphasis>
+    things when an input file changes,
+    so that the built software is up to date.
+    By default,
+    &SCons; keeps track of this through an
+    MD5 &signature;, or checksum, of the contents of each file,
+    although you can easily configure
+    &SCons; to use the
+    modification times (or time stamps)
+    instead.
+    You can even specify your own Python function
+    for deciding if an input file has changed.
+
+    </para>
+
+    <section>
+    <title>Using MD5 Signatures to Decide if a File Has Changed</title>
+
+      <para>
+
+      By default,
+      &SCons; keeps track of whether a file has changed
+      based on an MD5 checksum of the file's contents,
+      not the file's modification time.
+      This means that you may be surprised by the
+      default &SCons; behavior if you are used to the
+      &Make; convention of forcing
+      a rebuild by updating the file's modification time
+      (using the &touch; command, for example):
+
+      </para>
+
+      <scons_output example="ex1" os="posix">
+         <scons_output_command>scons -Q hello</scons_output_command>
+         <scons_output_command>touch hello.c</scons_output_command>
+         <scons_output_command>scons -Q hello</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Even though the file's modification time has changed,
+      &SCons; realizes that the contents of the
+      &hello_c; file have <emphasis>not</emphasis> changed,
+      and therefore that the &hello; program
+      need not be rebuilt.
+      This avoids unnecessary rebuilds when,
+      for example, someone rewrites the
+      contents of a file without making a change.
+      But if the contents of the file really do change,
+      then &SCons; detects the change
+      and rebuilds the program as required:
+
+      </para>
+
+      <scons_output example="ex1" os="posix">
+         <scons_output_command>scons -Q hello</scons_output_command>
+         <scons_output_command output="    [CHANGE THE CONTENTS OF hello.c]">edit hello.c</scons_output_command>
+         <scons_output_command>scons -Q hello</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Note that you can, if you wish,
+      specify this default behavior
+      (MD5 signatures) explicitly
+      using the &Decider; function as follows:
+
+      </para>
+
+      <sconstruct>
+        Program('hello.c')
+        Decider('MD5')
+      </sconstruct>
+
+      <para>
+
+      You can also use the string <literal>'content'</literal>
+      as a synonym for <literal>'MD5'</literal>
+      when calling the &Decider; function.
+
+      </para>
+
+      <section>
+      <title>Ramifications of Using MD5 Signatures</title>
+
+        <para>
+
+        Using MD5 signatures to decide if an input file has changed
+        has one surprising benefit:
+        if a source file has been changed
+        in such a way that the contents of the
+        rebuilt target file(s)
+        will be exactly the same as the last time
+        the file was built,
+        then any "downstream" target files
+        that depend on the rebuilt-but-not-changed target
+        file actually need not be rebuilt.
+
+        </para>
+
+        <para>
+
+        So if, for example,
+        a user were to only change a comment in a &hello_c; file,
+        then the rebuilt &hello_o; file
+        would be exactly the same as the one previously built
+        (assuming the compiler doesn't put any build-specific
+        information in the object file).
+        &SCons; would then realize that it would not
+        need to rebuild the &hello; program as follows:
+
+        </para>
+
+        <scons_output example="ex1" os="posix">
+           <scons_output_command>scons -Q hello</scons_output_command>
+           <scons_output_command output="  [CHANGE A COMMENT IN hello.c]" edit="STRIP CCCOM line">edit hello.c</scons_output_command>
+           <scons_output_command>scons -Q hello</scons_output_command>
+        </scons_output>
+
+        <para>
+
+        In essence, &SCons;
+        "short-circuits" any dependent builds
+        when it realizes that a target file
+        has been rebuilt to exactly the same file as the last build.
+        This does take some extra processing time
+        to read the contents of the target (&hello_o;) file,
+        but often saves time when the rebuild that was avoided
+        would have been time-consuming and expensive.
+
+        </para>
+
+      </section>
+
+    </section>
+
+    <section>
+    <title>Using Time Stamps to Decide If a File Has Changed</title>
+
+      <para>
+
+      If you prefer, you can
+      configure &SCons; to use the modification time
+      of a file, not the file contents,
+      when deciding if a target needs to be rebuilt.
+      &SCons; gives you two ways to use time stamps
+      to decide if an input file has changed
+      since the last time a target has been built.
+
+      </para>
+
+      <para>
+
+      The most familiar way to use time stamps
+      is the way &Make; does:
+      that is, have &SCons; decide
+      that a target must be rebuilt
+      if a source file's modification time is
+      <emphasis>newer</emphasis>
+      than the target file.
+      To do this, call the &Decider;
+      function as follows:
+
+      </para>
+
+      <scons_example name="newer">
+        <file name="SConstruct" printme="1">
+        Program('hello.c')
+        Decider('timestamp-newer')
+        </file>
+        <file name="hello.c">
+        int main() { printf("Hello, world!\n"); }
+        </file>
+      </scons_example>
+
+      <para>
+
+      This makes &SCons; act like &Make;
+      when a file's modification time is updated
+      (using the &touch; command, for example):
+
+      </para>
+
+      <scons_output example="newer" os="posix">
+         <scons_output_command>scons -Q hello</scons_output_command>
+         <scons_output_command>touch hello.c</scons_output_command>
+         <scons_output_command>scons -Q hello</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      And, in fact, because this behavior is the same
+      as the behavior of &Make;,
+      you can also use the string <literal>'make'</literal>
+      as a synonym for <literal>'timestamp-newer'</literal>
+      when calling the &Decider; function:
+
+      </para>
+
+      <sconstruct>
+        Program('hello.c')
+        Decider('make')
+      </sconstruct>
+
+      <para>
+
+      One drawback to using times stamps exactly like &Make;
+      is that if an input file's modification time suddenly
+      becomes <emphasis>older</emphasis> than a target file,
+      the target file will not be rebuilt.
+      This can happen if an old copy of a source file is restored
+      from a backup archive, for example.
+      The contents of the restored file will likely be different
+      than they were the last time a dependent target was built,
+      but the target won't be rebuilt
+      because the modification time of the source file
+      is not newer than the target.
+
+      </para>
+
+      <para>
+
+      Because &SCons; actually stores information
+      about the source files' time stamps whenever a target is built,
+      it can handle this situation by checking for
+      an exact match of the source file time stamp,
+      instead of just whether or not the source file
+      is newer than the target file.
+      To do this, specify the argument
+      <literal>'timestamp-match'</literal>
+      when calling the &Decider; function:
+
+      </para>
+
+      <scons_example name="match">
+        <file name="SConstruct" printme="1">
+        Program('hello.c')
+        Decider('timestamp-match')
+        </file>
+        <file name="hello.c">
+        int main() { printf("Hello, world!\n"); }
+        </file>
+      </scons_example>
+
+      <para>
+
+      When configured this way,
+      &SCons; will rebuild a target whenever
+      a source file's modification time has changed.
+      So if we use the <literal>touch -t</literal>
+      option to change the modification time of
+      &hello_c; to an old date (January 1, 1989),
+      &SCons; will still rebuild the target file:
+
+      </para>
+
+      <scons_output example="match" os="posix">
+         <scons_output_command>scons -Q hello</scons_output_command>
+         <scons_output_command>touch -t 198901010000 hello.c</scons_output_command>
+         <scons_output_command>scons -Q hello</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      In general, the only reason to prefer
+      <literal>timestamp-newer</literal>
+      instead of
+      <literal>timestamp-match</literal>,
+      would be if you have some specific reason
+      to require this &Make;-like behavior of 
+      not rebuilding a target when an otherwise-modified
+      source file is older.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Deciding If a File Has Changed Using Both MD Signatures and Time Stamps</title>
+
+      <para>
+
+      As a performance enhancement,
+      &SCons; provides a way to use
+      MD5 checksums of file contents
+      but to read those contents
+      only when the file's timestamp has changed.
+      To do this, call the &Decider;
+      function with <literal>'MD5-timestamp'</literal>
+      argument as follows:
+
+      </para>
+
+      <scons_example name="MD5-timestamp">
+        <file name="SConstruct" printme="1">
+        Program('hello.c')
+        Decider('MD5-timestamp')
+        </file>
+        <file name="hello.c">
+        int main() { printf("Hello, world!\n"); }
+        </file>
+      </scons_example>
+
+      <para>
+
+      So configured, &SCons will still behave like
+      it does when using <literal>Decider('MD5')</literal>:
+
+      </para>
+
+      <!--
+
+      We want to generate the output as follows,
+      but our "surrogate" system for generating the
+      output seems to get this wrong.
+      Just in-line the output for now.
+
+      <scons_output example="MD5-timestamp" os="posix">
+         <scons_output_command>scons -Q hello</scons_output_command>
+         <scons_output_command>touch hello.c</scons_output_command>
+         <scons_output_command>scons -Q hello</scons_output_command>
+       <scons_output_command output="    [CHANGE THE CONTENTS OF hello.c]">edit hello.c</scons_output_command>
+         <scons_output_command>scons -Q hello</scons_output_command>
+      </scons_output>
+
+      -->
+
+      <screen>
+         % <userinput>scons -Q hello</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+         % <userinput>touch hello.c</userinput>
+         % <userinput>scons -Q hello</userinput>
+         scons: `hello' is up to date.
+         % <userinput>edit hello.c</userinput>
+             [CHANGE THE CONTENTS OF hello.c]
+         % <userinput>scons -Q hello</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+      </screen>
+
+      <para>
+
+      However, the second call to &SCons; in the above output,
+      when the build is up-to-date,
+      will have been performed by simply looking at the
+      modification time of the &hello_c; file,
+      not by opening it and performing
+      an MD5 checksum calcuation on its contents.
+      This can significantly speed up many up-to-date builds.
+
+      </para>
+
+      <para>
+
+      The only drawback to using
+      <literal>Decider('MD5-timestamp')</literal>
+      is that &SCons; will <emphasis>not</emphasis>
+      rebuild a target file if a source file was modified
+      within one second of the last time &SCons; built the file.
+      While most developers are programming,
+      this isn't a problem in practice,
+      since it's unlikely that someone will have built
+      and then thought quickly enough to make a substantive
+      change to a source file within one second.
+      Certain build scripts or
+      continuous integration tools may, however,
+      rely on the ability to apply changes to files
+      automatically and then rebuild as quickly as possible,
+      in which case use of
+      <literal>Decider('MD5-timestamp')</literal>
+      may not be appropriate.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Writing Your Own Custom &Decider; Function</title>
+
+      <para>
+
+      The different string values that we've passed to
+      the &Decider; function are essentially used by &SCons;
+      to pick one of several specific internal functions
+      that implement various ways of deciding if a dependency
+      (usually a source file)
+      has changed since a target file has been built.
+      As it turns out,
+      you can also supply your own function
+      to decide if a dependency has changed.
+
+      </para>
+
+      <para>
+
+      For example, suppose we have an input file
+      that contains a lot of data,
+      in some specific regular format,
+      that is used to rebuild a lot of different target files,
+      but each target file really only depends on
+      one particular section of the input file.
+      We'd like to have each target file depend on
+      only its section of the input file.
+      However, since the input file may contain a lot of data,
+      we want to open the input file only if its timestamp has changed.
+      This could done with a custom
+      &Decider; function that might look something like this:
+
+      </para>
+
+      <scons_example name="function">
+        <file name="SConstruct" printme="1">
+        Program('hello.c')
+        def decide_if_changed(dependency, target, prev_ni):
+            if self.get_timestamp() != prev_ni.timestamp:
+                dep = str(dependency)
+                tgt = str(target)
+                if specific_part_of_file_has_changed(dep, tgt):
+                    return True
+            return False
+        Decider(decide_if_changed)
+        </file>
+        <file name="hello.c">
+        int main() { printf("Hello, world!\n"); }
+        </file>
+      </scons_example>
+
+      <para>
+
+      Note that in the function definition,
+      the <varname>dependency</varname>
+      (input file) is the first argument,
+      and then the &target;.
+      Both of these are passed to the functions as
+      SCons &Node; objects,
+      which we convert to strings using the Python
+      <function>str()</function>.
+
+      </para>
+
+      <para>
+
+      The third argument, <varname>prev_ni</varname>,
+      is an object that holds the
+      signature or timestamp information
+      that was recorded about the dependency
+      the last time the target was built.
+      A <varname>prev_ni</varname> object can hold
+      different information,
+      depending on the type of thing that the
+      <varname>dependency</varname> argument represents.
+      For normal files,
+      the <varname>prev_ni</varname> object
+      has the following attributes:
+
+      </para>
+
+      <variablelist>
+
+        <varlistentry>
+        <term>.csig</term>
+
+        <listitem>
+        <para>
+        The <emphasis>content signature</emphasis>,
+        or MD5 checksum, of the contents of the
+        <varname>dependency</varname>
+        file the list time the &target; was built.
+        </para>
+        </listitem>
+
+        </varlistentry>
+
+        <varlistentry>
+        <term>.size</term>
+
+        <listitem>
+        <para>
+        The size in bytes of the <varname>dependency</varname>
+        file the list time the target was built.
+        </para>
+        </listitem>
+
+        </varlistentry>
+
+        <varlistentry>
+        <term>.timestamp</term>
+
+        <listitem>
+        <para>
+        The modification time of the <varname>dependency</varname>
+        file the list time the &target; was built.
+        </para>
+        </listitem>
+
+        </varlistentry>
+
+      </variablelist>
+
+      <para>
+
+      Note that ignoring some of the arguments
+      in your custom &Decider; function
+      is a perfectly normal thing to do,
+      if they don't impact the way you want to
+      decide if the dependency file has changed.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Mixing Different Ways of Deciding If a File Has Changed</title>
+
+      <para>
+
+      The previous examples have all demonstrated calling
+      the global &Decider; function
+      to configure all dependency decisions that &SCons; makes.
+      Sometimes, however, you want to be able to configure
+      different decision-making for different targets.
+      When that's necessary, you can use the
+      <function>env.Decider</function>
+      method to affect only the configuration
+      decisions for targets built with a
+      specific construction environment.
+
+      </para>
+
+      <para>
+
+      For example, if we arbitrarily want to build
+      one program using MD5 checkums
+      and another using file modification times
+      from the same source
+      we might configure it this way:
+
+      </para>
+
+      <scons_example name="mixing">
+        <file name="SConstruct" printme="1">
+        env1 = Environment(CPPPATH = ['.'])
+        env2 = env1.Clone()
+        env2.Decider('timestamp-match')
+        env1.Program('prog-MD5', 'program1.c')
+        env2.Program('prog-timestamp', 'program2.c')
+        </file>
+        <file name="program1.c">
+        #include "inc.h"
+        int main() { printf("Hello, world!\n"); }
+        </file>
+        <file name="program2.c">
+        #include "inc.h"
+        int main() { printf("Hello, world!\n"); }
+        </file>
+        <file name="inc.h">
+        #define INC     1
+        </file>
+      </scons_example>
+
+      <para>
+
+      If both of the programs include the same
+      <filename>inc.h</filename> file,
+      then updating the modification time of
+      <filename>inc.h</filename>
+      (using the &touch; command)
+      will cause only <filename>prog-timestamp</filename>
+      to be rebuilt:
+
+      </para>
+
+      <scons_output example="mixing" os="posix">
+         <scons_output_command>scons -Q</scons_output_command>
+         <scons_output_command>touch inc.h</scons_output_command>
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Older Functions for Deciding When an Input File Has Changed</title>
+
+    <para>
+
+    &SCons; still supports two functions that used to be the
+    primary methods for configuring the
+    decision about whether or not an input file has changed.
+    Although they're not officially deprecated yet,
+    their use is discouraged,
+    mainly because they rely on a somewhat
+    confusing distinction between how
+    source files and target files are handled.
+    These functions are documented here mainly in case you
+    encounter them in existing &SConscript; files.
+
+    </para>
+  
+    <section>
+    <title>The &SourceSignatures; Function</title>
+
+      <para>
+
+      The &SourceSignatures; function is fairly straightforward,
+      and supports two different argument values
+      to configure whether source file changes should be decided
+      using MD5 signatures:
+
+      </para>
+
+      <sconstruct>
+        Program('hello.c')
+        SourceSignatures('MD5')
+      </sconstruct>
+
+      <para>
+
+      Or using time stamps:
+
+      </para>
+
+      <sconstruct>
+        Program('hello.c')
+        SourceSignatures('timestamp')
+      </sconstruct>
+
+      <para>
+
+      These are roughly equivalent to specifying
+      <function>Decider('MD5')</function>
+      or
+      <function>Decider('timestamp-match')</function>,
+      respectively,
+      although it only affects how SCons makes
+      decisions about dependencies on
+      <emphasis>source</emphasis> files--that is,
+      files that are not built from any other files.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &TargetSignatures; Function</title>
+
+      <para>
+
+      The &TargetSignatures; function
+      specifies how &SCons; decides
+      when a target file has changed
+      <emphasis>when it is used as a
+      dependency of (input to) another target</emphasis>--that is,
+      the &TargetSignatures; function configures
+      how the signatures of "intermediate" target files
+      are used when deciding if a "downstream" target file
+      must be rebuilt.
+      <footnote><para>
+      This easily-overlooked distinction between
+      how &SCons; decides if the target itself must be rebuilt
+      and how the target is then used to decide if a different
+      target must be rebuilt is one of the confusing
+      things that has led to the &TargetSignatures;
+      and &SourceSignatures; functions being
+      replaced by the simpler &Decider; function.
+      </para></footnote>
+
+      </para>
+
+      <para>
+
+      The &TargetSignatures; function supports the same
+      <literal>'MD5'</literal> and <literal>'timestamp'</literal>
+      argument values that are supported by the &SourceSignatures;,
+      with the same meanings, but applied to target files.
+      That is, in the example:
+
+      </para>
+
+      <sconstruct>
+        Program('hello.c')
+        TargetSignatures('MD5')
+      </sconstruct>
+
+      <para>
+
+      The MD5 checksum of the &hello_o; target file
+      will be used to decide if it has changed since the last
+      time the "downstream" &hello; target file was built.
+      And in the example:
+      
+      </para>
+
+      <sconstruct>
+        Program('hello.c')
+        TargetSignatures('timestamp')
+      </sconstruct>
+
+      <para>
+
+      The modification time of the &hello_o; target file
+      will be used to decide if it has changed since the last
+      time the "downstream" &hello; target file was built.
+
+      </para>
+
+      <para>
+
+      The &TargetSignatures; function supports
+      two additional argument values:
+      <literal>'source'</literal> and <literal>'build'</literal>.
+      The <literal>'source'</literal> argument
+      specifies that decisions involving
+      whether target files have changed
+      since a previous build
+      should use the same behavior
+      for the decisions configured for source files
+      (using the &SourceSignatures; function).
+      So in the example:
+
+      </para>
+
+      <sconstruct>
+        Program('hello.c')
+        TargetSignatures('source')
+        SourceSignatures('timestamp')
+      </sconstruct>
+
+      <para>
+
+      All files, both targets and sources,
+      will use modification times
+      when deciding if an input file
+      has changed since the last
+      time a target was built.
+
+      </para>
+
+      <para>
+
+      Lastly, the <literal>'build'</literal> argument
+      specifies that &SCons; should examine
+      the build status of a target file
+      and always rebuild a "downstream" target
+      if the target file was itself rebuilt,
+      without re-examining the contents or timestamp
+      of the newly-built target file.
+      If the target file was not rebuilt during
+      this &scons; invocation,
+      then the target file will be examined
+      the same way as configured by
+      the &SourceSignature; call
+      to decide if it has changed.
+
+      </para>
+
+      <para>
+
+      This mimics the behavior of
+      <literal>build signatures</literal>
+      in earlier versions of &SCons;.
+      A &buildsignature; re-combined
+      signatures of all the input files
+      that went into making the target file,
+      so that the target file itself
+      did not need to have its contents read
+      to compute an MD5 signature.
+      This can improve performance for some configurations,
+      but is generally not as effective as using
+      <literal>Decider('MD5-timestamp')</literal>.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Implicit Dependencies:  The &cv-CPPPATH; Construction Variable</title>
+
+    <para>
+
+    Now suppose that our "Hello, World!" program
+    actually has an <literal>#include</literal> line
+    to include the &hello_h; file in the compilation:
+
+    </para>
+
+    <scons_example name="include">
+      <file name="SConstruct">
+       Program('hello.c', CPPPATH = '.')
+      </file>
+      <file name="hello.c" printme="1">
+       #include &lt;hello.h&gt;
+       int
+       main()
+       {
+           printf("Hello, %s!\n", string);
+       }
+      </file>
+      <file name="hello.h">
+       #define string    "world"
+      </file>
+    </scons_example>
+
+    <para>
+
+    And, for completeness, the &hello_h; file looks like this:
+
+    </para>
+
+    <scons_example_file example="include"  name="hello.h">
+    </scons_example_file>
+
+    <para>
+
+    In this case, we want &SCons; to recognize that,
+    if the contents of the &hello_h; file change,
+    the &hello; program must be recompiled.
+    To do this, we need to modify the
+    &SConstruct; file like so:
+
+    </para>
+
+    <scons_example_file example="include"  name="SConstruct">
+    </scons_example_file>
+
+    <para>
+
+    The &cv-link-CPPPATH; value
+    tells &SCons; to look in the current directory
+    (<literal>'.'</literal>)
+    for any files included by C source files
+    (<filename>.c</filename> or <filename>.h</filename> files).
+    With this assignment in the &SConstruct; file:
+
+    </para>
+
+    <scons_output example="include" os="posix">
+       <scons_output_command>scons -Q hello</scons_output_command>
+       <scons_output_command>scons -Q hello</scons_output_command>
+       <scons_output_command output="    [CHANGE THE CONTENTS OF hello.h]">edit hello.h</scons_output_command>
+       <scons_output_command>scons -Q hello</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    First, notice that &SCons;
+    added the <literal>-I.</literal> argument
+    from the &cv-CPPPATH; variable
+    so that the compilation would find the
+    &hello_h; file in the local directory.
+
+    </para>
+
+    <para>
+
+    Second, realize that &SCons; knows that the &hello;
+    program must be rebuilt
+    because it scans the contents of
+    the &hello_c; file
+    for the <literal>#include</literal> lines that indicate
+    another file is being included in the compilation.
+    &SCons; records these as
+    <emphasis>implicit dependencies</emphasis>
+    of the target file,
+    Consequently,
+    when the &hello_h; file changes,
+    &SCons; realizes that the &hello_c; file includes it,
+    and rebuilds the resulting &hello; program
+    that depends on both the &hello_c; and &hello_h; files.
+
+    </para>
+
+    <para>
+
+    Like the &cv-link-LIBPATH; variable,
+    the &cv-CPPPATH; variable
+    may be a list of directories,
+    or a string separated by
+    the system-specific path separation character
+    (':' on POSIX/Linux, ';' on Windows).
+    Either way, &SCons; creates the
+    right command-line options
+    so that the following example:
+
+    </para>
+
+    <scons_example name="ex5">
+      <file name="SConstruct" printme="1">
+       Program('hello.c', CPPPATH = ['include', '/home/project/inc'])
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Will look like this on POSIX or Linux:
+
+    </para>
+
+    <scons_output example="ex5" os="posix">
+       <scons_output_command>scons -Q hello</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    And like this on Windows:
+
+    </para>
+
+    <scons_output example="ex5" os="win32">
+       <scons_output_command>scons -Q hello.exe</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Caching Implicit Dependencies</title>
+
+    <para>
+
+    Scanning each file for <literal>#include</literal> lines
+    does take some extra processing time.
+    When you're doing a full build of a large system,
+    the scanning time is usually a very small percentage
+    of the overall time spent on the build.
+    You're most likely to notice the scanning time,
+    however, when you <emphasis>rebuild</emphasis>
+    all or part of a large system:
+    &SCons; will likely take some extra time to "think about"
+    what must be built before it issues the
+    first build command
+    (or decides that everything is up to date
+    and nothing must be rebuilt).
+
+ <!--
+ Isn't this expensive? The answer is, it depends. If you do a full build of a
+ large system, the scanning time is insignificant. If you do a rebuild of a
+ large system, then Cons will spend a fair amount of time thinking about it
+ before it decides that nothing has to be done (although not necessarily more
+ time than make!). The good news is that Cons makes it very easy to
+ intelligently subset your build, when you are working on localized changes.
+ -->
+
+    </para>
+
+    <para>
+
+    In practice, having &SCons; scan files saves time
+    relative to the amount of potential time
+    lost to tracking down subtle problems
+    introduced by incorrect dependencies.
+    Nevertheless, the "waiting time"
+    while &SCons; scans files can annoy
+    individual developers waiting for their builds to finish.
+    Consequently, &SCons; lets you cache
+    the implicit dependencies
+    that its scanners find,
+    for use by later builds.
+    You can do this by specifying the
+    &implicit-cache; option on the command line:
+
+    </para>
+
+    <scons_output example="ex1">
+       <scons_output_command>scons -Q --implicit-cache hello</scons_output_command>
+       <scons_output_command>scons -Q hello</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    If you don't want to specify &implicit-cache;
+    on the command line each time,
+    you can make it the default behavior for your build
+    by setting the &implicit_cache; option
+    in an &SConscript; file:
+
+    </para>
+
+    <sconstruct>
+       SetOption('implicit_cache', 1)
+    </sconstruct>
+
+    <para>
+
+    &SCons; does not cache implicit dependencies like this by default
+    because the &implicit-cache; causes &SCons; to simply use the implicit
+    dependencies stored during the last run, without any checking
+    for whether or not those dependencies are still correct.
+    Specifically, this means &implicit-cache; instructs &SCons;
+    to <emphasis>not</emphasis> rebuild "correctly" in the
+    following cases:
+
+
+    </para>
+
+    <itemizedlist>
+
+      <listitem>
+        <para>
+
+        When &implicit-cache; is used, &SCons; will ignore any changes that
+        may have been made to search paths
+        (like &cv-CPPPATH; or &cv-LIBPATH;,).
+        This can lead to &SCons; not rebuilding a file if a change to
+        &cv-CPPPATH; would normally cause a different, same-named file from
+        a different directory to be used.
+
+        </para>
+      </listitem>
+
+      <listitem>
+        <para>
+
+        When &implicit-cache; is used, &SCons; will not detect if a
+        same-named file has been added to a directory that is earlier in
+        the search path than the directory in which the file was found
+        last time.
+
+        </para>
+      </listitem>
+
+    </itemizedlist>
+
+    <section>
+    <title>The &implicit-deps-changed; Option</title>
+
+      <para>
+
+      When using cached implicit dependencies,
+      sometimes you want to "start fresh"
+      and have &SCons; re-scan the files
+      for which it previously cached the dependencies.
+      For example,
+      if you have recently installed a new version of
+      external code that you use for compilation,
+      the external header files will have changed
+      and the previously-cached implicit dependencies
+      will be out of date.
+      You can update them by
+      running &SCons; with the &implicit-deps-changed; option:
+
+      </para>
+
+      <scons_output example="ex1">
+         <scons_output_command>scons -Q --implicit-deps-changed hello</scons_output_command>
+         <scons_output_command>scons -Q hello</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      In this case, &SCons; will re-scan all of the implicit dependencies
+      and cache updated copies of the information.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &implicit-deps-unchanged; Option</title>
+
+      <para>
+
+      By default when caching dependencies,
+      &SCons; notices when a file has been modified
+      and re-scans the file for any updated
+      implicit dependency information.
+      Sometimes, however, you may want
+      to force &SCons; to use the cached implicit dependencies,
+      even if the source files changed.
+      This can speed up a build for example,
+      when you have changed your source files
+      but know that you haven't changed
+      any <literal>#include</literal> lines.
+      In this case,
+      you can use the &implicit-deps-unchanged; option:
+
+      </para>
+
+      <scons_output example="ex1">
+         <scons_output_command>scons -Q --implicit-deps-unchanged hello</scons_output_command>
+         <scons_output_command>scons -Q hello</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      In this case,
+      &SCons; will assume that the cached implicit
+      dependencies are correct and
+      will not bother to re-scan changed files.
+      For typical builds after small,
+      incremental changes to source files,
+      the savings may not be very big,
+      but sometimes every bit of
+      improved performance counts.
+
+      </para>
+
+    </section>
+
+    <!--
+
+    <section>
+    <title>XXX max drift</title>
+
+      XXX SetOption('max_drift')
+
+    </section>
+
+    -->
+
+  </section>
+
+  <section>
+  <title>Explicit Dependencies:  the &Depends; Function</title>
+
+    <para>
+
+    Sometimes a file depends on another file
+    that is not detected by an &SCons; scanner.
+    For this situation,
+    &SCons; allows you to specific explicitly that one file
+    depends on another file,
+    and must be rebuilt whenever that file changes.
+    This is specified using the &Depends; method:
+
+    </para>
+
+    <programlisting>
+       hello = Program('hello.c')
+       Depends(hello, 'other_file')
+    </programlisting>
+
+    <!-- XXX mention that you can use arrays for target and source? -->
+
+    <screen>
+       % <userinput>scons -Q hello</userinput>
+       cc -c hello.c -o hello.o
+       cc -o hello hello.o
+       % <userinput>scons -Q hello</userinput>
+       scons: `hello' is up to date.
+       % <userinput>edit other_file</userinput>
+           [CHANGE THE CONTENTS OF other_file]
+       % <userinput>scons -Q hello</userinput>
+       cc -c hello.c -o hello.o
+       cc -o hello hello.o
+    </screen>
+
+    <para>
+
+    Note that the dependency
+    (the second argument to &Depends;)
+    may also be a list of Node objects
+    (for example, as returned by a call to a Builder):
+
+    </para>
+
+    <programlisting>
+       hello = Program('hello.c')
+       goodbye = Program('goodbye.c')
+       Depends(hello, goodbye)
+    </programlisting>
+
+    <para>
+
+    in which case the dependency or dependencies
+    will be built before the target(s):
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q hello</userinput>
+       cc -c goodbye.c -o goodbye.o
+       cc -o goodbye goodbye.o
+       cc -c hello.c -o hello.o
+       cc -o hello hello.o
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Dependencies From External Files:  the &ParseDepends;
+  Function</title>
+
+    <para>
+
+    &SCons; has built-in scanners for a number of languages. Sometimes
+    these scanners fail to extract certain implicit dependencies due
+    to limitations of the scanner implementation.
+
+    </para>
+
+    <para>
+
+    The following example illustrates a case where the built-in C
+    scanner is unable to extract the implicit dependency on a header
+    file.
+
+    </para>
+
+    <scons_example name="macroinc">
+      <file name="hello.c" printme="1">
+      #define FOO_HEADER &lt;foo.h&gt;
+      #include FOO_HEADER
+
+      int main() {
+          return FOO;
+      }
+      </file>
+      <file name="SConstruct">
+      Program('hello', 'hello.c', CPPPATH='.')
+      </file>
+      <file name="foo.h">
+      #define FOO 42
+      </file>
+    </scons_example>
+
+    <scons_output example="macroinc" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command output="   [CHANGE CONTENTS OF foo.h]"
+      >edit foo.h</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Apparently, the scanner does not know about the header dependency.
+    Being not a full-fledged C preprocessor, the scanner does not
+    expand the macro.
+
+    </para>
+
+    <para>
+
+    In these cases, you may also use the compiler to extract the
+    implicit dependencies. &ParseDepends; can parse the contents of
+    the compiler output in the style of &Make;, and explicitly
+    establish all of the listed dependencies.
+
+    </para>
+
+    <para>
+
+    The following example uses &ParseDepends; to process a compiler
+    generated dependency file which is generated as a side effect
+    during compilation of the object file:
+
+    </para>
+
+    <!-- XXX The ParseDepends example below fakes proper working by a
+    priori specification of the dependency file. The produced hello.d
+    file is not found (or used) for unknown reasons. -->
+
+    <scons_example name="parsedep">
+      <file name="hello.c">
+      #define FOO_HEADER &lt;foo.h&gt;
+      #include FOO_HEADER
+
+      int main() {
+          return FOO;
+      }
+      </file>
+      <file name="SConstruct" printme="1">
+      obj = Object('hello.c', CCFLAGS='-MD -MF hello.d', CPPPATH='.')
+      SideEffect('hello.d', obj)
+      ParseDepends('hello.d')
+      Program('hello', obj)
+      </file>
+      <file name="foo.h">
+      #define FOO 42
+      </file>
+      <file name="hello.d">
+      hello.o: hello.c foo.h
+      </file>
+    </scons_example>
+
+    <scons_output example="parsedep" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command output="   [CHANGE CONTENTS OF foo.h]"
+      >edit foo.h</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Parsing dependencies from a compiler-generated
+    <filename>.d</filename> file has a chicken-and-egg problem, that
+    causes unnecessary rebuilds:
+
+    </para>
+
+    <scons_example name="parsedeprebuild">
+      <file name="hello.c">
+      #define FOO_HEADER &lt;foo.h&gt;
+      #include FOO_HEADER
+
+      int main() {
+          return FOO;
+      }
+      </file>
+      <file name="SConstruct">
+      obj = Object('hello.c', CCFLAGS='-MD -MF hello.d', CPPPATH='.')
+      SideEffect('hello.d', obj)
+      ParseDepends('hello.d')
+      Program('hello', obj)
+      </file>
+      <file name="foo.h">
+      #define FOO 42
+      </file>
+    </scons_example>
+
+    <!--
+    <scons_output example="parsedeprebuild" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+    -->
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c -MD -MF hello.d -I. hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q --debug=explain</userinput>
+      scons: rebuilding `hello.o' because `foo.h' is a new dependency
+      cc -o hello.o -c -MD -MF hello.d -I. hello.c
+      % <userinput>scons -Q</userinput>
+      scons: `.' is up to date.
+    </screen>
+
+    <para>
+
+    In the first pass, the dependency file is generated while the
+    object file is compiled. At that time, &SCons; does not know about
+    the dependency on <filename>foo.h</filename>. In the second pass,
+    the object file is regenerated because <filename>foo.h</filename>
+    is detected as a new dependency.
+
+    </para>
+
+    <para>
+
+    &ParseDepends; immediately reads the specified file at invocation
+    time and just returns if the file does not exist. A dependency
+    file generated during the build process is not automatically
+    parsed again. Hence, the compiler-extracted dependencies are not
+    stored in the signature database during the same build pass. This
+    limitation of &ParseDepends; leads to unnecessary recompilations.
+    Therefore, &ParseDepends; should only be used if scanners are not
+    available for the employed language or not powerful enough for the
+    specific task.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Ignoring Dependencies:  the &Ignore; Function</title>
+
+    <para>
+
+    Sometimes it makes sense
+    to not rebuild a program,
+    even if a dependency file changes.
+    In this case,
+    you would tell &SCons; specifically
+    to ignore a dependency as follows:
+
+    </para>
+
+    <scons_example name="ignore">
+      <file name="SConstruct" printme="1">
+      hello = Program('hello.c')
+      Ignore(hello, 'hello.h')
+      </file>
+      <file name="hello.c">
+      #include "hello.h"
+      int main() { printf("Hello, %s!\n", string); }
+      </file>
+      <file name="hello.h">
+      #define string    "world"
+      </file>
+    </scons_example>
+
+    <!-- XXX mention that you can use lists for target and source? -->
+
+    <!--
+    <scons_output example="ignore">
+      <scons_output_command>scons -Q hello</scons_output_command>
+      <scons_output_command>scons -Q hello</scons_output_command>
+      <scons_output_command output="    [CHANGE THE CONTENTS OF hello.h]">edit hello.h</scons_output_command>
+      <scons_output_command>scons -Q hello</scons_output_command>
+      XXX THIS EXAMPLE SHOULD BE UP-TO-DATE! XXX
+    </scons_output>
+    -->
+
+    <screen>
+      % <userinput>scons -Q hello</userinput>
+      cc -c -o hello.o hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q hello</userinput>
+      scons: `hello' is up to date.
+      % <userinput>edit hello.h</userinput>
+        [CHANGE THE CONTENTS OF hello.h]
+      % <userinput>scons -Q hello</userinput>
+      scons: `hello' is up to date.
+    </screen>
+
+    <para>
+
+    Now, the above example is a little contrived,
+    because it's hard to imagine a real-world situation
+    where you wouldn't want to rebuild &hello;
+    if the &hello_h; file changed.
+    A more realistic example
+    might be if the &hello;
+    program is being built in a
+    directory that is shared between multiple systems
+    that have different copies of the
+    &stdio_h; include file.
+    In that case,
+    &SCons; would notice the differences between
+    the different systems' copies of &stdio_h;
+    and would rebuild &hello;
+    each time you change systems.
+    You could avoid these rebuilds as follows:
+
+    </para>
+
+    <programlisting>
+       hello = Program('hello.c', CPPPATH=['/usr/include'])
+       Ignore(hello, '/usr/include/stdio.h')
+    </programlisting>
+
+    <para>
+    &Ignore; can also be used to prevent a generated file from being built 
+    by default. This is due to the fact that directories depend on 
+    their contents.  So to ignore a generated file from the default build, 
+    you specify that the directory should ignore the generated file.
+    Note that the file will still be built if the user specifically 
+    requests the target on scons command line, or if the file is
+    a dependency of another file which is requested and/or is built
+    by default.
+    </para>
+
+    <scons_example name="ignore_explicit">
+      <file name="SConstruct" printme="1">
+      hello_obj=Object('hello.c')
+      hello = Program(hello_obj)
+      Ignore('.',[hello,hello_obj])
+      </file>
+      <file name="hello.c">
+      #include "stdio.h"
+      int main() { printf("Hello!\n"); }
+      </file>
+    </scons_example>
+
+    <scons_output example="ignore_explicit" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q hello</scons_output_command>
+      <scons_output_command>scons -Q hello</scons_output_command>
+    </scons_output>
+  </section>
+
+  <section>
+  <title>Order-Only Dependencies:  the &Requires; Function</title>
+
+    <para>
+
+    Occasionally,
+    it may be useful to specify that a certain
+    file or directory must, if necessary,
+    be built or created before some other target is built,
+    but that changes to that file or directory
+    do <emphasis>not</emphasis>
+    require that the target itself be rebuilt.
+    Such a relationship is called an
+    <emphasis>order-only dependency</emphasis>
+    because it only affects the order in which
+    things must be built--the dependency before the target--but
+    it is not a strict dependency relationship
+    because the target should not
+    change in response to changes in the dependent file.
+
+    </para>
+
+    <para>
+
+    For example, suppose that you want to create a file
+    every time you run a build
+    that identifies the time the build was performed,
+    the version number, etc.,
+    and which is included in every program that you build.
+    The version file's contents will change every build.
+    If you specify a normal dependency relationship,
+    then every program that depends on
+    that file would be rebuilt every time you ran &SCons;.
+    For example, we could use some Python code in
+    a &SConstruct; file to create a new <filename>version.c</filename> file
+    with a string containing the current date every time
+    we run &SCons;,
+    and then link a program with the resulting object file
+    by listing <filename>version.c</filename> in the sources:
+
+    </para>
+
+    <scons_example name="no-Requires">
+      <file name="SConstruct" printme="1">
+      import time
+
+      version_c_text = """
+      char *date = "%s";
+      """ % time.ctime(time.time())
+      open('version.c', 'w').write(version_c_text)
+
+      hello = Program(['hello.c', 'version.c'])
+      </file>
+      <file name="hello.c">
+      extern char *date;
+      int main() { printf("Hello, %s!  I was built: %s\n", date); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    If we list <filename>version.c</filename> as an actual source file,
+    though, then <filename>version.o</filename>
+    will get rebuilt every time we run &SCons;
+    (because the &SConstruct; file itself changes
+    the contents of <filename>version.c</filename>)
+    and the <filename>hello</filename> executable
+    will get re-linked every time
+    (because the <filename>version.o</filename> file changes):
+
+    </para>
+
+    <!--
+
+    <scons_output example="no-Requires">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      gcc -o hello.o -c hello.c
+      gcc -o version.o -c version.c
+      gcc -o hello hello.o version.o
+      % <userinput>scons -Q</userinput>
+      gcc -o version.o -c version.c
+      gcc -o hello hello.o version.o
+      % <userinput>scons -Q</userinput>
+      gcc -o version.o -c version.c
+      gcc -o hello hello.o version.o
+    </screen>
+
+    <para>
+
+    One solution is to use the &Requires; function
+    to specify that the <filename>version.o</filename>
+    must be rebuilt before it is used by the link step,
+    but that changes to <filename>version.o</filename>
+    should not actually cause the <filename>hello</filename>
+    executable to be re-linked:
+
+    </para>
+
+    <scons_example name="Requires">
+      <file name="SConstruct" printme="1">
+      import time
+
+      version_c_text = """
+      char *date = "%s";
+      """ % time.ctime(time.time())
+      open('version.c', 'w').write(version_c_text)
+
+      version_obj = Object('version.c')
+
+      hello = Program('hello.c',
+                      LINKFLAGS = str(version_obj[0]))
+
+      Requires(hello, version_obj)
+      </file>
+      <file name="hello.c">
+      extern char *date;
+      int main() { printf("Hello, %s!  I was built: %s\n", date); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Notice that because we can no longer list <filename>version.c</filename>
+    as one of the sources for the <filename>hello</filename> program,
+    we have to find some other way to get it into the link command line.
+    For this example, we're cheating a bit and stuffing the
+    object file name (extracted from <literal>version_obj</literal>
+    list returned by the &b-Object; call)
+    into the &cv-link-LINKFLAGS; variable,
+    because &cv-LINKFLAGS; is already included
+    in the &cv-link-LINKCOM; command line.
+
+    </para>
+
+    <para>
+
+    With these changes,
+    we get the desired behavior of
+    re-building the <filename>version.o</filename> file,
+    and therefore re-linking the <filename>hello</filename> executable,
+    only when the <filename>hello.c</filename> has changed:
+
+    </para>
+
+    <scons_output example="Requires">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command output="    [CHANGE THE CONTENTS OF hello.c]">edit hello.c</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>The &AlwaysBuild; Function</title>
+
+    <para>
+
+    How &SCons; handles dependencies can also be affected
+    by the &AlwaysBuild; method.
+    When a file is passed to the &AlwaysBuild; method,
+    like so:
+
+    </para>
+
+    <scons_example name="AlwaysBuild">
+      <file name="SConstruct" printme="1">
+      hello = Program('hello.c')
+      AlwaysBuild(hello)
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, %s!\n", string); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Then the specified target file (&hello; in our example)
+    will always be considered out-of-date and
+    rebuilt whenever that target file is evaluated
+    while walking the dependency graph:
+
+    </para>
+
+    <scons_output example="AlwaysBuild">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The &AlwaysBuild; function has a somewhat misleading name,
+    because it does not actually mean the target file will
+    be rebuilt every single time &SCons; is invoked.
+    Instead, it means that the target will, in fact,
+    be rebuilt whenever the target file is encountered
+    while evaluating the targets specified on
+    the command line (and their dependencies).
+    So specifying some other target on the command line,
+    a target that does <emphasis>not</emphasis>
+    itself depend on the &AlwaysBuild; target,
+    will still be rebuilt only if it's out-of-date
+    with respect to its dependencies:
+
+    </para>
+
+    <scons_output example="AlwaysBuild">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q hello.o</scons_output_command>
+    </scons_output>
+
+    <!--
+
+      XXX AlwaysBuild() and Alias Nodes
+
+      XXX AlwaysBuild() and Dir Nodes
+
+      XXX AlwaysBuild() with no sources
+
+    -->
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>The &Salt; Method</title>
+
+    <para>
+
+    XXX Salt() (are we going to implement this ?)
+
+        original Cons classic POD documentation:
+
+=head2 The C<Salt> method
+
+The C<Salt> method adds a constant value to the signature calculation
+for every derived file.  It is invoked as follows:
+
+  Salt $string;
+
+Changing the Salt value will force a complete rebuild of every derived
+file.  This can be used to force rebuilds in certain desired
+circumstances.  For example,
+
+  Salt `uname -s`;
+
+Would force a complete rebuild of every derived file whenever the
+operating system on which the build is performed (as reported by C<uname
+-s>) changes.
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/depends.xml b/doc/user/depends.xml
new file mode 100644
index 0000000..b72f41f
--- /dev/null
+++ b/doc/user/depends.xml
@@ -0,0 +1,1776 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  So far we've seen how &SCons; handles one-time builds.
+  But one of the main functions of a build tool like &SCons;
+  is to rebuild only what is necessary
+  when source files change--or, put another way,
+  &SCons; should <emphasis>not</emphasis>
+  waste time rebuilding things that don't need to be rebuilt.
+  You can see this at work simply by re-invoking &SCons;
+  after building our simple &hello; example:
+
+  </para>
+
+  
+
+  <screen>
+     % <userinput>scons -Q</userinput>
+     cc -o hello.o -c hello.c
+     cc -o hello hello.o
+     % <userinput>scons -Q</userinput>
+     scons: `.' is up to date.
+  </screen>
+
+  <para>
+
+  The second time it is executed,
+  &SCons; realizes that the &hello; program
+  is up-to-date with respect to the current &hello_c; source file,
+  and avoids rebuilding it.
+  You can see this more clearly by naming
+  the &hello; program explicitly on the command line:
+
+  </para>
+
+  <screen>
+     % <userinput>scons -Q hello</userinput>
+     cc -o hello.o -c hello.c
+     cc -o hello hello.o
+     % <userinput>scons -Q hello</userinput>
+     scons: `hello' is up to date.
+  </screen>
+
+  <para>
+
+  Note that &SCons; reports <literal>"...is up to date"</literal>
+  only for target files named explicitly on the command line,
+  to avoid cluttering the output.
+
+  </para>
+
+  <section>
+  <title>Deciding When an Input File Has Changed:  the &Decider; Function</title>
+
+    <para>
+
+    Another aspect of avoiding unnecessary rebuilds
+    is the fundamental build tool behavior
+    of <emphasis>rebuilding</emphasis>
+    things when an input file changes,
+    so that the built software is up to date.
+    By default,
+    &SCons; keeps track of this through an
+    MD5 &signature;, or checksum, of the contents of each file,
+    although you can easily configure
+    &SCons; to use the
+    modification times (or time stamps)
+    instead.
+    You can even specify your own Python function
+    for deciding if an input file has changed.
+
+    </para>
+
+    <section>
+    <title>Using MD5 Signatures to Decide if a File Has Changed</title>
+
+      <para>
+
+      By default,
+      &SCons; keeps track of whether a file has changed
+      based on an MD5 checksum of the file's contents,
+      not the file's modification time.
+      This means that you may be surprised by the
+      default &SCons; behavior if you are used to the
+      &Make; convention of forcing
+      a rebuild by updating the file's modification time
+      (using the &touch; command, for example):
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q hello</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+         % <userinput>touch hello.c</userinput>
+         % <userinput>scons -Q hello</userinput>
+         scons: `hello' is up to date.
+      </screen>
+
+      <para>
+
+      Even though the file's modification time has changed,
+      &SCons; realizes that the contents of the
+      &hello_c; file have <emphasis>not</emphasis> changed,
+      and therefore that the &hello; program
+      need not be rebuilt.
+      This avoids unnecessary rebuilds when,
+      for example, someone rewrites the
+      contents of a file without making a change.
+      But if the contents of the file really do change,
+      then &SCons; detects the change
+      and rebuilds the program as required:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q hello</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+         % <userinput>edit hello.c</userinput>
+             [CHANGE THE CONTENTS OF hello.c]
+         % <userinput>scons -Q hello</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+      </screen>
+
+      <para>
+
+      Note that you can, if you wish,
+      specify this default behavior
+      (MD5 signatures) explicitly
+      using the &Decider; function as follows:
+
+      </para>
+
+      <programlisting>
+        Program('hello.c')
+        Decider('MD5')
+      </programlisting>
+
+      <para>
+
+      You can also use the string <literal>'content'</literal>
+      as a synonym for <literal>'MD5'</literal>
+      when calling the &Decider; function.
+
+      </para>
+
+      <section>
+      <title>Ramifications of Using MD5 Signatures</title>
+
+        <para>
+
+        Using MD5 signatures to decide if an input file has changed
+        has one surprising benefit:
+        if a source file has been changed
+        in such a way that the contents of the
+        rebuilt target file(s)
+        will be exactly the same as the last time
+        the file was built,
+        then any "downstream" target files
+        that depend on the rebuilt-but-not-changed target
+        file actually need not be rebuilt.
+
+        </para>
+
+        <para>
+
+        So if, for example,
+        a user were to only change a comment in a &hello_c; file,
+        then the rebuilt &hello_o; file
+        would be exactly the same as the one previously built
+        (assuming the compiler doesn't put any build-specific
+        information in the object file).
+        &SCons; would then realize that it would not
+        need to rebuild the &hello; program as follows:
+
+        </para>
+
+        <screen>
+           % <userinput>scons -Q hello</userinput>
+           cc -o hello.o -c hello.c
+           cc -o hello hello.o
+           % <userinput>edit hello.c</userinput>
+             [CHANGE A COMMENT IN hello.c]
+           % <userinput>scons -Q hello</userinput>
+           cc -o hello.o -c hello.c
+           scons: `hello' is up to date.
+        </screen>
+
+        <para>
+
+        In essence, &SCons;
+        "short-circuits" any dependent builds
+        when it realizes that a target file
+        has been rebuilt to exactly the same file as the last build.
+        This does take some extra processing time
+        to read the contents of the target (&hello_o;) file,
+        but often saves time when the rebuild that was avoided
+        would have been time-consuming and expensive.
+
+        </para>
+
+      </section>
+
+    </section>
+
+    <section>
+    <title>Using Time Stamps to Decide If a File Has Changed</title>
+
+      <para>
+
+      If you prefer, you can
+      configure &SCons; to use the modification time
+      of a file, not the file contents,
+      when deciding if a target needs to be rebuilt.
+      &SCons; gives you two ways to use time stamps
+      to decide if an input file has changed
+      since the last time a target has been built.
+
+      </para>
+
+      <para>
+
+      The most familiar way to use time stamps
+      is the way &Make; does:
+      that is, have &SCons; decide
+      that a target must be rebuilt
+      if a source file's modification time is
+      <emphasis>newer</emphasis>
+      than the target file.
+      To do this, call the &Decider;
+      function as follows:
+
+      </para>
+
+      <programlisting>
+        Program('hello.c')
+        Decider('timestamp-newer')
+      </programlisting>
+
+      <para>
+
+      This makes &SCons; act like &Make;
+      when a file's modification time is updated
+      (using the &touch; command, for example):
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q hello</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+         % <userinput>touch hello.c</userinput>
+         % <userinput>scons -Q hello</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+      </screen>
+
+      <para>
+
+      And, in fact, because this behavior is the same
+      as the behavior of &Make;,
+      you can also use the string <literal>'make'</literal>
+      as a synonym for <literal>'timestamp-newer'</literal>
+      when calling the &Decider; function:
+
+      </para>
+
+      <programlisting>
+        Program('hello.c')
+        Decider('make')
+      </programlisting>
+
+      <para>
+
+      One drawback to using times stamps exactly like &Make;
+      is that if an input file's modification time suddenly
+      becomes <emphasis>older</emphasis> than a target file,
+      the target file will not be rebuilt.
+      This can happen if an old copy of a source file is restored
+      from a backup archive, for example.
+      The contents of the restored file will likely be different
+      than they were the last time a dependent target was built,
+      but the target won't be rebuilt
+      because the modification time of the source file
+      is not newer than the target.
+
+      </para>
+
+      <para>
+
+      Because &SCons; actually stores information
+      about the source files' time stamps whenever a target is built,
+      it can handle this situation by checking for
+      an exact match of the source file time stamp,
+      instead of just whether or not the source file
+      is newer than the target file.
+      To do this, specify the argument
+      <literal>'timestamp-match'</literal>
+      when calling the &Decider; function:
+
+      </para>
+
+      <programlisting>
+        Program('hello.c')
+        Decider('timestamp-match')
+      </programlisting>
+
+      <para>
+
+      When configured this way,
+      &SCons; will rebuild a target whenever
+      a source file's modification time has changed.
+      So if we use the <literal>touch -t</literal>
+      option to change the modification time of
+      &hello_c; to an old date (January 1, 1989),
+      &SCons; will still rebuild the target file:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q hello</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+         % <userinput>touch -t 198901010000 hello.c</userinput>
+         % <userinput>scons -Q hello</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+      </screen>
+
+      <para>
+
+      In general, the only reason to prefer
+      <literal>timestamp-newer</literal>
+      instead of
+      <literal>timestamp-match</literal>,
+      would be if you have some specific reason
+      to require this &Make;-like behavior of 
+      not rebuilding a target when an otherwise-modified
+      source file is older.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Deciding If a File Has Changed Using Both MD Signatures and Time Stamps</title>
+
+      <para>
+
+      As a performance enhancement,
+      &SCons; provides a way to use
+      MD5 checksums of file contents
+      but to read those contents
+      only when the file's timestamp has changed.
+      To do this, call the &Decider;
+      function with <literal>'MD5-timestamp'</literal>
+      argument as follows:
+
+      </para>
+
+      <programlisting>
+        Program('hello.c')
+        Decider('MD5-timestamp')
+      </programlisting>
+
+      <para>
+
+      So configured, &SCons; will still behave like
+      it does when using <literal>Decider('MD5')</literal>:
+
+      </para>
+
+      <!--
+
+      We want to generate the output as follows,
+      but our "surrogate" system for generating the
+      output seems to get this wrong.
+      Just in-line the output for now.
+
+      <scons_output example="MD5-timestamp" os="posix">
+         <scons_output_command>scons -Q hello</scons_output_command>
+         <scons_output_command>touch hello.c</scons_output_command>
+         <scons_output_command>scons -Q hello</scons_output_command>
+       <scons_output_command output="    [CHANGE THE CONTENTS OF hello.c]">edit hello.c</scons_output_command>
+         <scons_output_command>scons -Q hello</scons_output_command>
+      </scons_output>
+
+      -->
+
+      <screen>
+         % <userinput>scons -Q hello</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+         % <userinput>touch hello.c</userinput>
+         % <userinput>scons -Q hello</userinput>
+         scons: `hello' is up to date.
+         % <userinput>edit hello.c</userinput>
+             [CHANGE THE CONTENTS OF hello.c]
+         % <userinput>scons -Q hello</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+      </screen>
+
+      <para>
+
+      However, the second call to &SCons; in the above output,
+      when the build is up-to-date,
+      will have been performed by simply looking at the
+      modification time of the &hello_c; file,
+      not by opening it and performing
+      an MD5 checksum calcuation on its contents.
+      This can significantly speed up many up-to-date builds.
+
+      </para>
+
+      <para>
+
+      The only drawback to using
+      <literal>Decider('MD5-timestamp')</literal>
+      is that &SCons; will <emphasis>not</emphasis>
+      rebuild a target file if a source file was modified
+      within one second of the last time &SCons; built the file.
+      While most developers are programming,
+      this isn't a problem in practice,
+      since it's unlikely that someone will have built
+      and then thought quickly enough to make a substantive
+      change to a source file within one second.
+      Certain build scripts or
+      continuous integration tools may, however,
+      rely on the ability to apply changes to files
+      automatically and then rebuild as quickly as possible,
+      in which case use of
+      <literal>Decider('MD5-timestamp')</literal>
+      may not be appropriate.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Writing Your Own Custom &Decider; Function</title>
+
+      <para>
+
+      The different string values that we've passed to
+      the &Decider; function are essentially used by &SCons;
+      to pick one of several specific internal functions
+      that implement various ways of deciding if a dependency
+      (usually a source file)
+      has changed since a target file has been built.
+      As it turns out,
+      you can also supply your own function
+      to decide if a dependency has changed.
+
+      </para>
+
+      <para>
+
+      For example, suppose we have an input file
+      that contains a lot of data,
+      in some specific regular format,
+      that is used to rebuild a lot of different target files,
+      but each target file really only depends on
+      one particular section of the input file.
+      We'd like to have each target file depend on
+      only its section of the input file.
+      However, since the input file may contain a lot of data,
+      we want to open the input file only if its timestamp has changed.
+      This could done with a custom
+      &Decider; function that might look something like this:
+
+      </para>
+
+      <programlisting>
+        Program('hello.c')
+        def decide_if_changed(dependency, target, prev_ni):
+            if self.get_timestamp() != prev_ni.timestamp:
+                dep = str(dependency)
+                tgt = str(target)
+                if specific_part_of_file_has_changed(dep, tgt):
+                    return True
+            return False
+        Decider(decide_if_changed)
+      </programlisting>
+
+      <para>
+
+      Note that in the function definition,
+      the <varname>dependency</varname>
+      (input file) is the first argument,
+      and then the &target;.
+      Both of these are passed to the functions as
+      SCons &Node; objects,
+      which we convert to strings using the Python
+      <function>str()</function>.
+
+      </para>
+
+      <para>
+
+      The third argument, <varname>prev_ni</varname>,
+      is an object that holds the
+      signature or timestamp information
+      that was recorded about the dependency
+      the last time the target was built.
+      A <varname>prev_ni</varname> object can hold
+      different information,
+      depending on the type of thing that the
+      <varname>dependency</varname> argument represents.
+      For normal files,
+      the <varname>prev_ni</varname> object
+      has the following attributes:
+
+      </para>
+
+      <variablelist>
+
+        <varlistentry>
+        <term>.csig</term>
+
+        <listitem>
+        <para>
+        The <emphasis>content signature</emphasis>,
+        or MD5 checksum, of the contents of the
+        <varname>dependency</varname>
+        file the list time the &target; was built.
+        </para>
+        </listitem>
+
+        </varlistentry>
+
+        <varlistentry>
+        <term>.size</term>
+
+        <listitem>
+        <para>
+        The size in bytes of the <varname>dependency</varname>
+        file the list time the target was built.
+        </para>
+        </listitem>
+
+        </varlistentry>
+
+        <varlistentry>
+        <term>.timestamp</term>
+
+        <listitem>
+        <para>
+        The modification time of the <varname>dependency</varname>
+        file the list time the &target; was built.
+        </para>
+        </listitem>
+
+        </varlistentry>
+
+      </variablelist>
+
+      <para>
+
+      Note that ignoring some of the arguments
+      in your custom &Decider; function
+      is a perfectly normal thing to do,
+      if they don't impact the way you want to
+      decide if the dependency file has changed.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Mixing Different Ways of Deciding If a File Has Changed</title>
+
+      <para>
+
+      The previous examples have all demonstrated calling
+      the global &Decider; function
+      to configure all dependency decisions that &SCons; makes.
+      Sometimes, however, you want to be able to configure
+      different decision-making for different targets.
+      When that's necessary, you can use the
+      <function>env.Decider</function>
+      method to affect only the configuration
+      decisions for targets built with a
+      specific construction environment.
+
+      </para>
+
+      <para>
+
+      For example, if we arbitrarily want to build
+      one program using MD5 checkums
+      and another using file modification times
+      from the same source
+      we might configure it this way:
+
+      </para>
+
+      <programlisting>
+        env1 = Environment(CPPPATH = ['.'])
+        env2 = env1.Clone()
+        env2.Decider('timestamp-match')
+        env1.Program('prog-MD5', 'program1.c')
+        env2.Program('prog-timestamp', 'program2.c')
+      </programlisting>
+
+      <para>
+
+      If both of the programs include the same
+      <filename>inc.h</filename> file,
+      then updating the modification time of
+      <filename>inc.h</filename>
+      (using the &touch; command)
+      will cause only <filename>prog-timestamp</filename>
+      to be rebuilt:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         cc -o program1.o -c -I. program1.c
+         cc -o prog-MD5 program1.o
+         cc -o program2.o -c -I. program2.c
+         cc -o prog-timestamp program2.o
+         % <userinput>touch inc.h</userinput>
+         % <userinput>scons -Q</userinput>
+         cc -o program2.o -c -I. program2.c
+         cc -o prog-timestamp program2.o
+      </screen>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Older Functions for Deciding When an Input File Has Changed</title>
+
+    <para>
+
+    &SCons; still supports two functions that used to be the
+    primary methods for configuring the
+    decision about whether or not an input file has changed.
+    Although they're not officially deprecated yet,
+    their use is discouraged,
+    mainly because they rely on a somewhat
+    confusing distinction between how
+    source files and target files are handled.
+    These functions are documented here mainly in case you
+    encounter them in existing &SConscript; files.
+
+    </para>
+  
+    <section>
+    <title>The &SourceSignatures; Function</title>
+
+      <para>
+
+      The &SourceSignatures; function is fairly straightforward,
+      and supports two different argument values
+      to configure whether source file changes should be decided
+      using MD5 signatures:
+
+      </para>
+
+      <programlisting>
+        Program('hello.c')
+        SourceSignatures('MD5')
+      </programlisting>
+
+      <para>
+
+      Or using time stamps:
+
+      </para>
+
+      <programlisting>
+        Program('hello.c')
+        SourceSignatures('timestamp')
+      </programlisting>
+
+      <para>
+
+      These are roughly equivalent to specifying
+      <function>Decider('MD5')</function>
+      or
+      <function>Decider('timestamp-match')</function>,
+      respectively,
+      although it only affects how SCons makes
+      decisions about dependencies on
+      <emphasis>source</emphasis> files--that is,
+      files that are not built from any other files.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &TargetSignatures; Function</title>
+
+      <para>
+
+      The &TargetSignatures; function
+      specifies how &SCons; decides
+      when a target file has changed
+      <emphasis>when it is used as a
+      dependency of (input to) another target</emphasis>--that is,
+      the &TargetSignatures; function configures
+      how the signatures of "intermediate" target files
+      are used when deciding if a "downstream" target file
+      must be rebuilt.
+      <footnote><para>
+      This easily-overlooked distinction between
+      how &SCons; decides if the target itself must be rebuilt
+      and how the target is then used to decide if a different
+      target must be rebuilt is one of the confusing
+      things that has led to the &TargetSignatures;
+      and &SourceSignatures; functions being
+      replaced by the simpler &Decider; function.
+      </para></footnote>
+
+      </para>
+
+      <para>
+
+      The &TargetSignatures; function supports the same
+      <literal>'MD5'</literal> and <literal>'timestamp'</literal>
+      argument values that are supported by the &SourceSignatures;,
+      with the same meanings, but applied to target files.
+      That is, in the example:
+
+      </para>
+
+      <programlisting>
+        Program('hello.c')
+        TargetSignatures('MD5')
+      </programlisting>
+
+      <para>
+
+      The MD5 checksum of the &hello_o; target file
+      will be used to decide if it has changed since the last
+      time the "downstream" &hello; target file was built.
+      And in the example:
+      
+      </para>
+
+      <programlisting>
+        Program('hello.c')
+        TargetSignatures('timestamp')
+      </programlisting>
+
+      <para>
+
+      The modification time of the &hello_o; target file
+      will be used to decide if it has changed since the last
+      time the "downstream" &hello; target file was built.
+
+      </para>
+
+      <para>
+
+      The &TargetSignatures; function supports
+      two additional argument values:
+      <literal>'source'</literal> and <literal>'build'</literal>.
+      The <literal>'source'</literal> argument
+      specifies that decisions involving
+      whether target files have changed
+      since a previous build
+      should use the same behavior
+      for the decisions configured for source files
+      (using the &SourceSignatures; function).
+      So in the example:
+
+      </para>
+
+      <programlisting>
+        Program('hello.c')
+        TargetSignatures('source')
+        SourceSignatures('timestamp')
+      </programlisting>
+
+      <para>
+
+      All files, both targets and sources,
+      will use modification times
+      when deciding if an input file
+      has changed since the last
+      time a target was built.
+
+      </para>
+
+      <para>
+
+      Lastly, the <literal>'build'</literal> argument
+      specifies that &SCons; should examine
+      the build status of a target file
+      and always rebuild a "downstream" target
+      if the target file was itself rebuilt,
+      without re-examining the contents or timestamp
+      of the newly-built target file.
+      If the target file was not rebuilt during
+      this &scons; invocation,
+      then the target file will be examined
+      the same way as configured by
+      the &SourceSignature; call
+      to decide if it has changed.
+
+      </para>
+
+      <para>
+
+      This mimics the behavior of
+      <literal>build signatures</literal>
+      in earlier versions of &SCons;.
+      A &buildsignature; re-combined
+      signatures of all the input files
+      that went into making the target file,
+      so that the target file itself
+      did not need to have its contents read
+      to compute an MD5 signature.
+      This can improve performance for some configurations,
+      but is generally not as effective as using
+      <literal>Decider('MD5-timestamp')</literal>.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Implicit Dependencies:  The &cv-CPPPATH; Construction Variable</title>
+
+    <para>
+
+    Now suppose that our "Hello, World!" program
+    actually has an <literal>#include</literal> line
+    to include the &hello_h; file in the compilation:
+
+    </para>
+
+    <programlisting>
+       #include &lt;hello.h&gt;
+       int
+       main()
+       {
+           printf("Hello, %s!\n", string);
+       }
+    </programlisting>
+
+    <para>
+
+    And, for completeness, the &hello_h; file looks like this:
+
+    </para>
+
+    
+    <programlisting>
+       #define string    "world"
+      </programlisting>
+
+    <para>
+
+    In this case, we want &SCons; to recognize that,
+    if the contents of the &hello_h; file change,
+    the &hello; program must be recompiled.
+    To do this, we need to modify the
+    &SConstruct; file like so:
+
+    </para>
+
+    
+    <programlisting>
+       Program('hello.c', CPPPATH = '.')
+      </programlisting>
+
+    <para>
+
+    The &cv-link-CPPPATH; value
+    tells &SCons; to look in the current directory
+    (<literal>'.'</literal>)
+    for any files included by C source files
+    (<filename>.c</filename> or <filename>.h</filename> files).
+    With this assignment in the &SConstruct; file:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q hello</userinput>
+       cc -o hello.o -c -I. hello.c
+       cc -o hello hello.o
+       % <userinput>scons -Q hello</userinput>
+       scons: `hello' is up to date.
+       % <userinput>edit hello.h</userinput>
+           [CHANGE THE CONTENTS OF hello.h]
+       % <userinput>scons -Q hello</userinput>
+       cc -o hello.o -c -I. hello.c
+       cc -o hello hello.o
+    </screen>
+
+    <para>
+
+    First, notice that &SCons;
+    added the <literal>-I.</literal> argument
+    from the &cv-CPPPATH; variable
+    so that the compilation would find the
+    &hello_h; file in the local directory.
+
+    </para>
+
+    <para>
+
+    Second, realize that &SCons; knows that the &hello;
+    program must be rebuilt
+    because it scans the contents of
+    the &hello_c; file
+    for the <literal>#include</literal> lines that indicate
+    another file is being included in the compilation.
+    &SCons; records these as
+    <emphasis>implicit dependencies</emphasis>
+    of the target file,
+    Consequently,
+    when the &hello_h; file changes,
+    &SCons; realizes that the &hello_c; file includes it,
+    and rebuilds the resulting &hello; program
+    that depends on both the &hello_c; and &hello_h; files.
+
+    </para>
+
+    <para>
+
+    Like the &cv-link-LIBPATH; variable,
+    the &cv-CPPPATH; variable
+    may be a list of directories,
+    or a string separated by
+    the system-specific path separation character
+    (':' on POSIX/Linux, ';' on Windows).
+    Either way, &SCons; creates the
+    right command-line options
+    so that the following example:
+
+    </para>
+
+    <programlisting>
+       Program('hello.c', CPPPATH = ['include', '/home/project/inc'])
+    </programlisting>
+
+    <para>
+
+    Will look like this on POSIX or Linux:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q hello</userinput>
+       cc -o hello.o -c -Iinclude -I/home/project/inc hello.c
+       cc -o hello hello.o
+    </screen>
+
+    <para>
+
+    And like this on Windows:
+
+    </para>
+
+    <screen>
+       C:\><userinput>scons -Q hello.exe</userinput>
+       
+       scons: warning: No installed VCs
+       File "&lt;stdin&gt;", line 67, in __call__
+       
+       scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+       File "&lt;stdin&gt;", line 67, in __call__
+       cl /Fohello.obj /c hello.c /nologo /Iinclude /I\home\project\inc
+       link /nologo /OUT:hello.exe hello.obj
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Caching Implicit Dependencies</title>
+
+    <para>
+
+    Scanning each file for <literal>#include</literal> lines
+    does take some extra processing time.
+    When you're doing a full build of a large system,
+    the scanning time is usually a very small percentage
+    of the overall time spent on the build.
+    You're most likely to notice the scanning time,
+    however, when you <emphasis>rebuild</emphasis>
+    all or part of a large system:
+    &SCons; will likely take some extra time to "think about"
+    what must be built before it issues the
+    first build command
+    (or decides that everything is up to date
+    and nothing must be rebuilt).
+
+ <!--
+ Isn't this expensive? The answer is, it depends. If you do a full build of a
+ large system, the scanning time is insignificant. If you do a rebuild of a
+ large system, then Cons will spend a fair amount of time thinking about it
+ before it decides that nothing has to be done (although not necessarily more
+ time than make!). The good news is that Cons makes it very easy to
+ intelligently subset your build, when you are working on localized changes.
+ -->
+
+    </para>
+
+    <para>
+
+    In practice, having &SCons; scan files saves time
+    relative to the amount of potential time
+    lost to tracking down subtle problems
+    introduced by incorrect dependencies.
+    Nevertheless, the "waiting time"
+    while &SCons; scans files can annoy
+    individual developers waiting for their builds to finish.
+    Consequently, &SCons; lets you cache
+    the implicit dependencies
+    that its scanners find,
+    for use by later builds.
+    You can do this by specifying the
+    &implicit-cache; option on the command line:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q --implicit-cache hello</userinput>
+       cc -o hello.o -c hello.c
+       cc -o hello hello.o
+       % <userinput>scons -Q hello</userinput>
+       scons: `hello' is up to date.
+    </screen>
+
+    <para>
+
+    If you don't want to specify &implicit-cache;
+    on the command line each time,
+    you can make it the default behavior for your build
+    by setting the &implicit_cache; option
+    in an &SConscript; file:
+
+    </para>
+
+    <programlisting>
+       SetOption('implicit_cache', 1)
+    </programlisting>
+
+    <para>
+
+    &SCons; does not cache implicit dependencies like this by default
+    because the &implicit-cache; causes &SCons; to simply use the implicit
+    dependencies stored during the last run, without any checking
+    for whether or not those dependencies are still correct.
+    Specifically, this means &implicit-cache; instructs &SCons;
+    to <emphasis>not</emphasis> rebuild "correctly" in the
+    following cases:
+
+
+    </para>
+
+    <itemizedlist>
+
+      <listitem>
+        <para>
+
+        When &implicit-cache; is used, &SCons; will ignore any changes that
+        may have been made to search paths
+        (like &cv-CPPPATH; or &cv-LIBPATH;,).
+        This can lead to &SCons; not rebuilding a file if a change to
+        &cv-CPPPATH; would normally cause a different, same-named file from
+        a different directory to be used.
+
+        </para>
+      </listitem>
+
+      <listitem>
+        <para>
+
+        When &implicit-cache; is used, &SCons; will not detect if a
+        same-named file has been added to a directory that is earlier in
+        the search path than the directory in which the file was found
+        last time.
+
+        </para>
+      </listitem>
+
+    </itemizedlist>
+
+    <section>
+    <title>The &implicit-deps-changed; Option</title>
+
+      <para>
+
+      When using cached implicit dependencies,
+      sometimes you want to "start fresh"
+      and have &SCons; re-scan the files
+      for which it previously cached the dependencies.
+      For example,
+      if you have recently installed a new version of
+      external code that you use for compilation,
+      the external header files will have changed
+      and the previously-cached implicit dependencies
+      will be out of date.
+      You can update them by
+      running &SCons; with the &implicit-deps-changed; option:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q --implicit-deps-changed hello</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+         % <userinput>scons -Q hello</userinput>
+         scons: `hello' is up to date.
+      </screen>
+
+      <para>
+
+      In this case, &SCons; will re-scan all of the implicit dependencies
+      and cache updated copies of the information.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>The &implicit-deps-unchanged; Option</title>
+
+      <para>
+
+      By default when caching dependencies,
+      &SCons; notices when a file has been modified
+      and re-scans the file for any updated
+      implicit dependency information.
+      Sometimes, however, you may want
+      to force &SCons; to use the cached implicit dependencies,
+      even if the source files changed.
+      This can speed up a build for example,
+      when you have changed your source files
+      but know that you haven't changed
+      any <literal>#include</literal> lines.
+      In this case,
+      you can use the &implicit-deps-unchanged; option:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q --implicit-deps-unchanged hello</userinput>
+         cc -o hello.o -c hello.c
+         cc -o hello hello.o
+         % <userinput>scons -Q hello</userinput>
+         scons: `hello' is up to date.
+      </screen>
+
+      <para>
+
+      In this case,
+      &SCons; will assume that the cached implicit
+      dependencies are correct and
+      will not bother to re-scan changed files.
+      For typical builds after small,
+      incremental changes to source files,
+      the savings may not be very big,
+      but sometimes every bit of
+      improved performance counts.
+
+      </para>
+
+    </section>
+
+    <!--
+
+    <section>
+    <title>XXX max drift</title>
+
+      XXX SetOption('max_drift')
+
+    </section>
+
+    -->
+
+  </section>
+
+  <section>
+  <title>Explicit Dependencies:  the &Depends; Function</title>
+
+    <para>
+
+    Sometimes a file depends on another file
+    that is not detected by an &SCons; scanner.
+    For this situation,
+    &SCons; allows you to specific explicitly that one file
+    depends on another file,
+    and must be rebuilt whenever that file changes.
+    This is specified using the &Depends; method:
+
+    </para>
+
+    <programlisting>
+       hello = Program('hello.c')
+       Depends(hello, 'other_file')
+    </programlisting>
+
+    <!-- XXX mention that you can use arrays for target and source? -->
+
+    <screen>
+       % <userinput>scons -Q hello</userinput>
+       cc -c hello.c -o hello.o
+       cc -o hello hello.o
+       % <userinput>scons -Q hello</userinput>
+       scons: `hello' is up to date.
+       % <userinput>edit other_file</userinput>
+           [CHANGE THE CONTENTS OF other_file]
+       % <userinput>scons -Q hello</userinput>
+       cc -c hello.c -o hello.o
+       cc -o hello hello.o
+    </screen>
+
+    <para>
+
+    Note that the dependency
+    (the second argument to &Depends;)
+    may also be a list of Node objects
+    (for example, as returned by a call to a Builder):
+
+    </para>
+
+    <programlisting>
+       hello = Program('hello.c')
+       goodbye = Program('goodbye.c')
+       Depends(hello, goodbye)
+    </programlisting>
+
+    <para>
+
+    in which case the dependency or dependencies
+    will be built before the target(s):
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q hello</userinput>
+       cc -c goodbye.c -o goodbye.o
+       cc -o goodbye goodbye.o
+       cc -c hello.c -o hello.o
+       cc -o hello hello.o
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Dependencies From External Files:  the &ParseDepends;
+  Function</title>
+
+    <para>
+
+    &SCons; has built-in scanners for a number of languages. Sometimes
+    these scanners fail to extract certain implicit dependencies due
+    to limitations of the scanner implementation.
+
+    </para>
+
+    <para>
+
+    The following example illustrates a case where the built-in C
+    scanner is unable to extract the implicit dependency on a header
+    file.
+
+    </para>
+
+    <programlisting>
+      #define FOO_HEADER &lt;foo.h&gt;
+      #include FOO_HEADER
+
+      int main() {
+          return FOO;
+      }
+    </programlisting>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c -I. hello.c
+      cc -o hello hello.o
+      % <userinput>edit foo.h</userinput>
+         [CHANGE CONTENTS OF foo.h]
+      % <userinput>scons -Q</userinput>
+      scons: `.' is up to date.
+    </screen>
+
+    <para>
+
+    Apparently, the scanner does not know about the header dependency.
+    Being not a full-fledged C preprocessor, the scanner does not
+    expand the macro.
+
+    </para>
+
+    <para>
+
+    In these cases, you may also use the compiler to extract the
+    implicit dependencies. &ParseDepends; can parse the contents of
+    the compiler output in the style of &Make;, and explicitly
+    establish all of the listed dependencies.
+
+    </para>
+
+    <para>
+
+    The following example uses &ParseDepends; to process a compiler
+    generated dependency file which is generated as a side effect
+    during compilation of the object file:
+
+    </para>
+
+    <!-- XXX The ParseDepends example below fakes proper working by a
+    priori specification of the dependency file. The produced hello.d
+    file is not found (or used) for unknown reasons. -->
+
+    <programlisting>
+      obj = Object('hello.c', CCFLAGS='-MD -MF hello.d', CPPPATH='.')
+      SideEffect('hello.d', obj)
+      ParseDepends('hello.d')
+      Program('hello', obj)
+    </programlisting>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c -MD -MF hello.d -I. hello.c
+      cc -o hello hello.o
+      % <userinput>edit foo.h</userinput>
+         [CHANGE CONTENTS OF foo.h]
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c -MD -MF hello.d -I. hello.c
+    </screen>
+
+    <para>
+
+    Parsing dependencies from a compiler-generated
+    <filename>.d</filename> file has a chicken-and-egg problem, that
+    causes unnecessary rebuilds:
+
+    </para>
+
+    
+
+    <!--
+    <scons_output example="parsedeprebuild" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+    -->
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c -MD -MF hello.d -I. hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q --debug=explain</userinput>
+      scons: rebuilding `hello.o' because `foo.h' is a new dependency
+      cc -o hello.o -c -MD -MF hello.d -I. hello.c
+      % <userinput>scons -Q</userinput>
+      scons: `.' is up to date.
+    </screen>
+
+    <para>
+
+    In the first pass, the dependency file is generated while the
+    object file is compiled. At that time, &SCons; does not know about
+    the dependency on <filename>foo.h</filename>. In the second pass,
+    the object file is regenerated because <filename>foo.h</filename>
+    is detected as a new dependency.
+
+    </para>
+
+    <para>
+
+    &ParseDepends; immediately reads the specified file at invocation
+    time and just returns if the file does not exist. A dependency
+    file generated during the build process is not automatically
+    parsed again. Hence, the compiler-extracted dependencies are not
+    stored in the signature database during the same build pass. This
+    limitation of &ParseDepends; leads to unnecessary recompilations.
+    Therefore, &ParseDepends; should only be used if scanners are not
+    available for the employed language or not powerful enough for the
+    specific task.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Ignoring Dependencies:  the &Ignore; Function</title>
+
+    <para>
+
+    Sometimes it makes sense
+    to not rebuild a program,
+    even if a dependency file changes.
+    In this case,
+    you would tell &SCons; specifically
+    to ignore a dependency as follows:
+
+    </para>
+
+    <programlisting>
+      hello = Program('hello.c')
+      Ignore(hello, 'hello.h')
+    </programlisting>
+
+    <!-- XXX mention that you can use lists for target and source? -->
+
+    <!--
+    <scons_output example="ignore">
+      <scons_output_command>scons -Q hello</scons_output_command>
+      <scons_output_command>scons -Q hello</scons_output_command>
+      <scons_output_command output="    [CHANGE THE CONTENTS OF hello.h]">edit hello.h</scons_output_command>
+      <scons_output_command>scons -Q hello</scons_output_command>
+      XXX THIS EXAMPLE SHOULD BE UP-TO-DATE! XXX
+    </scons_output>
+    -->
+
+    <screen>
+      % <userinput>scons -Q hello</userinput>
+      cc -c -o hello.o hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q hello</userinput>
+      scons: `hello' is up to date.
+      % <userinput>edit hello.h</userinput>
+        [CHANGE THE CONTENTS OF hello.h]
+      % <userinput>scons -Q hello</userinput>
+      scons: `hello' is up to date.
+    </screen>
+
+    <para>
+
+    Now, the above example is a little contrived,
+    because it's hard to imagine a real-world situation
+    where you wouldn't want to rebuild &hello;
+    if the &hello_h; file changed.
+    A more realistic example
+    might be if the &hello;
+    program is being built in a
+    directory that is shared between multiple systems
+    that have different copies of the
+    &stdio_h; include file.
+    In that case,
+    &SCons; would notice the differences between
+    the different systems' copies of &stdio_h;
+    and would rebuild &hello;
+    each time you change systems.
+    You could avoid these rebuilds as follows:
+
+    </para>
+
+    <programlisting>
+       hello = Program('hello.c', CPPPATH=['/usr/include'])
+       Ignore(hello, '/usr/include/stdio.h')
+    </programlisting>
+
+    <para>
+    &Ignore; can also be used to prevent a generated file from being built 
+    by default. This is due to the fact that directories depend on 
+    their contents.  So to ignore a generated file from the default build, 
+    you specify that the directory should ignore the generated file.
+    Note that the file will still be built if the user specifically 
+    requests the target on scons command line, or if the file is
+    a dependency of another file which is requested and/or is built
+    by default.
+    </para>
+
+    <programlisting>
+      hello_obj=Object('hello.c')
+      hello = Program(hello_obj)
+      Ignore('.',[hello,hello_obj])
+    </programlisting>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      scons: `.' is up to date.
+      % <userinput>scons -Q hello</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q hello</userinput>
+      scons: `hello' is up to date.
+    </screen>
+  </section>
+
+  <section>
+  <title>Order-Only Dependencies:  the &Requires; Function</title>
+
+    <para>
+
+    Occasionally,
+    it may be useful to specify that a certain
+    file or directory must, if necessary,
+    be built or created before some other target is built,
+    but that changes to that file or directory
+    do <emphasis>not</emphasis>
+    require that the target itself be rebuilt.
+    Such a relationship is called an
+    <emphasis>order-only dependency</emphasis>
+    because it only affects the order in which
+    things must be built--the dependency before the target--but
+    it is not a strict dependency relationship
+    because the target should not
+    change in response to changes in the dependent file.
+
+    </para>
+
+    <para>
+
+    For example, suppose that you want to create a file
+    every time you run a build
+    that identifies the time the build was performed,
+    the version number, etc.,
+    and which is included in every program that you build.
+    The version file's contents will change every build.
+    If you specify a normal dependency relationship,
+    then every program that depends on
+    that file would be rebuilt every time you ran &SCons;.
+    For example, we could use some Python code in
+    a &SConstruct; file to create a new <filename>version.c</filename> file
+    with a string containing the current date every time
+    we run &SCons;,
+    and then link a program with the resulting object file
+    by listing <filename>version.c</filename> in the sources:
+
+    </para>
+
+    <programlisting>
+      import time
+
+      version_c_text = """
+      char *date = "%s";
+      """ % time.ctime(time.time())
+      open('version.c', 'w').write(version_c_text)
+
+      hello = Program(['hello.c', 'version.c'])
+    </programlisting>
+
+    <para>
+
+    If we list <filename>version.c</filename> as an actual source file,
+    though, then <filename>version.o</filename>
+    will get rebuilt every time we run &SCons;
+    (because the &SConstruct; file itself changes
+    the contents of <filename>version.c</filename>)
+    and the <filename>hello</filename> executable
+    will get re-linked every time
+    (because the <filename>version.o</filename> file changes):
+
+    </para>
+
+    <!--
+
+    <scons_output example="no-Requires">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      gcc -o hello.o -c hello.c
+      gcc -o version.o -c version.c
+      gcc -o hello hello.o version.o
+      % <userinput>scons -Q</userinput>
+      gcc -o version.o -c version.c
+      gcc -o hello hello.o version.o
+      % <userinput>scons -Q</userinput>
+      gcc -o version.o -c version.c
+      gcc -o hello hello.o version.o
+    </screen>
+
+    <para>
+
+    One solution is to use the &Requires; function
+    to specify that the <filename>version.o</filename>
+    must be rebuilt before it is used by the link step,
+    but that changes to <filename>version.o</filename>
+    should not actually cause the <filename>hello</filename>
+    executable to be re-linked:
+
+    </para>
+
+    <programlisting>
+      import time
+
+      version_c_text = """
+      char *date = "%s";
+      """ % time.ctime(time.time())
+      open('version.c', 'w').write(version_c_text)
+
+      version_obj = Object('version.c')
+
+      hello = Program('hello.c',
+                      LINKFLAGS = str(version_obj[0]))
+
+      Requires(hello, version_obj)
+    </programlisting>
+
+    <para>
+
+    Notice that because we can no longer list <filename>version.c</filename>
+    as one of the sources for the <filename>hello</filename> program,
+    we have to find some other way to get it into the link command line.
+    For this example, we're cheating a bit and stuffing the
+    object file name (extracted from <literal>version_obj</literal>
+    list returned by the &b-Object; call)
+    into the &cv-link-LINKFLAGS; variable,
+    because &cv-LINKFLAGS; is already included
+    in the &cv-link-LINKCOM; command line.
+
+    </para>
+
+    <para>
+
+    With these changes,
+    we get the desired behavior of
+    re-building the <filename>version.o</filename> file,
+    and therefore re-linking the <filename>hello</filename> executable,
+    only when the <filename>hello.c</filename> has changed:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o version.o -c version.c
+      cc -o hello.o -c hello.c
+      cc -o hello version.o hello.o
+      % <userinput>scons -Q</userinput>
+      scons: `.' is up to date.
+      % <userinput>edit hello.c</userinput>
+          [CHANGE THE CONTENTS OF hello.c]
+      % <userinput>scons -Q</userinput>
+      cc -o version.o -c version.c
+      cc -o hello.o -c hello.c
+      cc -o hello version.o hello.o
+      % <userinput>scons -Q</userinput>
+      scons: `.' is up to date.
+    </screen>
+
+  </section>
+
+  <section>
+  <title>The &AlwaysBuild; Function</title>
+
+    <para>
+
+    How &SCons; handles dependencies can also be affected
+    by the &AlwaysBuild; method.
+    When a file is passed to the &AlwaysBuild; method,
+    like so:
+
+    </para>
+
+    <programlisting>
+      hello = Program('hello.c')
+      AlwaysBuild(hello)
+    </programlisting>
+
+    <para>
+
+    Then the specified target file (&hello; in our example)
+    will always be considered out-of-date and
+    rebuilt whenever that target file is evaluated
+    while walking the dependency graph:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q</userinput>
+      cc -o hello hello.o
+    </screen>
+
+    <para>
+
+    The &AlwaysBuild; function has a somewhat misleading name,
+    because it does not actually mean the target file will
+    be rebuilt every single time &SCons; is invoked.
+    Instead, it means that the target will, in fact,
+    be rebuilt whenever the target file is encountered
+    while evaluating the targets specified on
+    the command line (and their dependencies).
+    So specifying some other target on the command line,
+    a target that does <emphasis>not</emphasis>
+    itself depend on the &AlwaysBuild; target,
+    will still be rebuilt only if it's out-of-date
+    with respect to its dependencies:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+      % <userinput>scons -Q hello.o</userinput>
+      scons: `hello.o' is up to date.
+    </screen>
+
+    <!--
+
+      XXX AlwaysBuild() and Alias Nodes
+
+      XXX AlwaysBuild() and Dir Nodes
+
+      XXX AlwaysBuild() with no sources
+
+    -->
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>The &Salt; Method</title>
+
+    <para>
+
+    XXX Salt() (are we going to implement this ?)
+
+        original Cons classic POD documentation:
+
+=head2 The C<Salt> method
+
+The C<Salt> method adds a constant value to the signature calculation
+for every derived file.  It is invoked as follows:
+
+  Salt $string;
+
+Changing the Salt value will force a complete rebuild of every derived
+file.  This can be used to force rebuilds in certain desired
+circumstances.  For example,
+
+  Salt `uname -s`;
+
+Would force a complete rebuild of every derived file whenever the
+operating system on which the build is performed (as reported by C<uname
+-s>) changes.
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/environments.in b/doc/user/environments.in
new file mode 100644
index 0000000..124aaaa
--- /dev/null
+++ b/doc/user/environments.in
@@ -0,0 +1,1678 @@
+<!--
+
+     Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+     Permission is hereby granted, free of charge, to any person obtaining
+     a copy of this software and associated documentation files (the
+     "Software"), to deal in the Software without restriction, including
+     without limitation the rights to use, copy, modify, merge, publish,
+     distribute, sublicense, and/or sell copies of the Software, and to
+     permit persons to whom the Software is furnished to do so, subject to
+     the following conditions:
+
+     The above copyright notice and this permission notice shall be included
+     in all copies or substantial portions of the Software.
+
+     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+     KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+     WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+     LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+     OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 More on construction environments
+
+As previously mentioned, a B<construction environment> is an object that
+has a set of keyword/value pairs and a set of methods, and which is used
+to tell Cons how target files should be built.  This section describes
+how Cons uses and expands construction environment values to control its
+build behavior.
+
+=head2 Construction variable expansion
+
+Construction variables from a construction environment are expanded
+by preceding the keyword with a C<%> (percent sign):
+
+     Construction variables:
+	XYZZY => 'abracadabra',
+
+     The string:  "The magic word is:  %XYZZY!"
+     expands to:  "The magic word is:  abracadabra!"
+
+A construction variable name may be surrounded by C<{> and C<}> (curly
+braces), which are stripped as part of the expansion.  This can
+sometimes be necessary to separate a variable expansion from trailing
+alphanumeric characters:
+
+     Construction variables:
+	OPT    => 'value1',
+	OPTION => 'value2',
+
+     The string:  "%OPT %{OPT}ION %OPTION %{OPTION}"
+     expands to:  "value1 value1ION value2 value2"
+
+Construction variable expansion is recursive, that is, a string
+containing C<%->expansions after substitution will be re-expanded until
+no further substitutions can be made:
+
+     Construction variables:
+	STRING => 'The result is:  %FOO',
+	FOO    => '%BAR',
+	BAR    => 'final value',
+
+     The string:  "The string says:  %STRING"
+     expands to:  "The string says:  The result is:  final value"
+
+If a construction variable is not defined in an environment, then the
+null string is substituted:
+
+     Construction variables:
+	FOO => 'value1',
+	BAR => 'value2',
+
+     The string:  "%FOO <%NO_VARIABLE> %BAR"
+     expands to:  "value1 <> value2"
+
+A doubled C<%%> will be replaced by a single C<%>:
+
+     The string:  "Here is a percent sign:  %%"
+     expands to:  "Here is a percent sign: %"
+
+=head2 Default construction variables
+
+When you specify no arguments when creating a new construction
+environment:
+
+     $env = new cons();
+
+Cons creates a reference to a new, default construction
+environment. This contains a number of construction variables and some
+methods. At the present writing, the default construction variables on a
+UNIX system are:
+
+     CC            => 'cc',
+     CFLAGS        => '',
+     CCCOM         => '%CC %CFLAGS %_IFLAGS -c %< -o %>',
+     CXX           => '%CC',
+     CXXFLAGS      => '%CFLAGS',
+     CXXCOM        => '%CXX %CXXFLAGS %_IFLAGS -c %< -o %>',
+     INCDIRPREFIX  => '-I',
+     INCDIRSUFFIX  => '',
+     LINK          => '%CXX',
+     LINKCOM       => '%LINK %LDFLAGS -o %> %< %_LDIRS %LIBS',
+     LINKMODULECOM => '%LD -r -o %> %<',
+     LIBDIRPREFIX  => '-L',
+     LIBDIRSUFFIX  => '',
+     AR		=> 'ar',
+     ARFLAGS	=> 'r',
+     ARCOM		=> ['%AR %ARFLAGS %> %<', '%RANLIB %>'],
+     RANLIB	=> 'ranlib',
+     AS		=> 'as',
+     ASFLAGS	=> '',
+     ASCOM		=> '%AS %ASFLAGS %< -o %>',
+     LD		=> 'ld',
+     LDFLAGS	=> '',
+     PREFLIB	=> 'lib',
+     SUFLIB	=> '.a',
+     SUFLIBS	=> '.so:.a',
+     SUFOBJ	=> '.o',
+     SIGNATURE     => [ '*' => 'build' ],
+     ENV		=> { 'PATH' => '/bin:/usr/bin' },
+
+
+And on a Windows system (Windows NT), the default construction variables
+are (unless the default rule style is set using the B<DefaultRules>
+method):
+
+     CC		=> 'cl',
+     CFLAGS	=> '/nologo',
+     CCCOM		=> '%CC %CFLAGS %_IFLAGS /c %< /Fo%>',
+     CXXCOM        => '%CXX %CXXFLAGS %_IFLAGS /c %< /Fo%>',
+     INCDIRPREFIX  => '/I',
+     INCDIRSUFFIX  => '',
+     LINK          => 'link',
+     LINKCOM       => '%LINK %LDFLAGS /out:%> %< %_LDIRS %LIBS',
+     LINKMODULECOM => '%LD /r /o %> %<',
+     LIBDIRPREFIX  => '/LIBPATH:',
+     LIBDIRSUFFIX  => '',
+     AR            => 'lib',
+     ARFLAGS       => '/nologo ',
+     ARCOM         => "%AR %ARFLAGS /out:%> %<",
+     RANLIB        => '',
+     LD            => 'link',
+     LDFLAGS       => '/nologo ',
+     PREFLIB       => '',
+     SUFEXE	=> '.exe',
+     SUFLIB	=> '.lib',
+     SUFLIBS	=> '.dll:.lib',
+     SUFOBJ	=> '.obj',
+     SIGNATURE     => [ '*' => 'build' ],
+
+These variables are used by the various methods associated with the
+environment. In particular, any method that ultimately invokes an external
+command will substitute these variables into the final command, as
+appropriate. For example, the C<Objects> method takes a number of source
+files and arranges to derive, if necessary, the corresponding object
+files:
+
+     Objects $env 'foo.c', 'bar.c';
+
+This will arrange to produce, if necessary, F<foo.o> and F<bar.o>. The
+command invoked is simply C<%CCCOM>, which expands, through substitution,
+to the appropriate external command required to build each object. The
+substitution rules will be discussed in detail in the next section.
+
+The construction variables are also used for other purposes. For example,
+C<CPPPATH> is used to specify a colon-separated path of include
+directories. These are intended to be passed to the C preprocessor and are
+also used by the C-file scanning machinery to determine the dependencies
+involved in a C Compilation.
+
+Variables beginning with underscore are created by various methods,
+and should normally be considered ``internal'' variables. For example,
+when a method is called which calls for the creation of an object from
+a C source, the variable C<_IFLAGS> is created: this corresponds to the
+C<-I> switches required by the C compiler to represent the directories
+specified by C<CPPPATH>.
+
+Note that, for any particular environment, the value of a variable is set
+once, and then never reset (to change a variable, you must create a new
+environment. Methods are provided for copying existing environments for this
+purpose). Some internal variables, such as C<_IFLAGS> are created on demand,
+but once set, they remain fixed for the life of the environment.
+
+The C<CFLAGS>, C<LDFLAGS>, and C<ARFLAGS> variables all supply a place
+for passing options to the compiler, loader, and archiver, respectively.
+
+The C<INCDIRPREFIX> and C<INCDIRSUFFIX> variables specify option
+strings to be appended to the beginning and end, respectively, of each
+include directory so that the compiler knows where to find F<.h> files.
+Similarly, the C<LIBDIRPREFIX> and C<LIBDIRSUFFIX> variables specify the
+option string to be appended to the beginning of and end, respectively,
+of each directory that the linker should search for libraries.
+
+Another variable, C<ENV>, is used to determine the system environment during
+the execution of an external command. By default, the only environment
+variable that is set is C<PATH>, which is the execution path for a UNIX
+command. For the utmost reproducibility, you should really arrange to set
+your own execution path, in your top-level F<Construct> file (or perhaps by
+importing an appropriate construction package with the Perl C<use>
+command). The default variables are intended to get you off the ground.
+
+=head2 Expanding variables in construction commands
+
+Within a construction command, construction variables will be expanded
+according to the rules described above.  In addition to normal variable
+expansion from the construction environment, construction commands also
+expand the following pseudo-variables to insert the specific input and
+output files in the command line that will be executed:
+
+=over 10
+
+=item %>
+
+The target file name.  In a multi-target command, this expands to the
+first target mentioned.)
+
+=item %0
+
+Same as C<%E<gt>>.
+
+=item %1, %2, ..., %9
+
+These refer to the first through ninth input file, respectively.
+
+=item %E<lt>
+
+The full set of input file names. If any of these have been used
+anywhere else in the current command line (via C<%1>, C<%2>, etc.), then
+those will be deleted from the list provided by C<%E<lt>>. Consider the
+following command found in a F<Conscript> file in the F<test> directory:
+
+     Command $env 'tgt', qw(foo bar baz), qq(
+	echo %< -i %1 > %>
+	echo %< -i %2 >> %>
+	echo %< -i %3 >> %>
+     );
+
+If F<tgt> needed to be updated, then this would result in the execution of
+the following commands, assuming that no remapping has been established for
+the F<test> directory:
+
+     echo test/bar test/baz -i test/foo > test/tgt
+     echo test/foo test/baz -i test/bar >> test/tgt
+     echo test/foo test/bar -i test/baz >> test/tgt
+
+=back
+
+Any of the above pseudo-variables may be followed immediately by one of
+the following suffixes to select a portion of the expanded path name:
+
+     :a    the absolute path to the file name
+     :b    the directory plus the file name stripped of any suffix
+     :d    the directory
+     :f    the file name
+     :s    the file name suffix
+     :F    the file name stripped of any suffix
+     :S    the absolute path path to a Linked source file
+
+Continuing with the above example, C<%E<lt>:f> would expand to C<foo bar baz>,
+and C<%E<gt>:d> would expand to C<test>.
+
+There are additional C<%> elements which affect the command line(s):
+
+=over 10
+
+=item %[ %]
+
+It is possible to programmatically rewrite part of the command by
+enclosing part of it between C<%[> and C<%]>.  This will call the
+construction variable named as the first word enclosed in the brackets
+as a Perl code reference; the results of this call will be used to
+replace the contents of the brackets in the command line.  For example,
+given an existing input file named F<tgt.in>:
+
+     @keywords = qw(foo bar baz);
+     $env = new cons(X_COMMA => sub { join(",", @_) });
+     Command $env 'tgt', 'tgt.in', qq(
+	echo '# Keywords: %[X_COMMA @keywords %]' > %>
+	cat %< >> %>
+     );
+
+This will execute:
+
+     echo '# Keywords: foo,bar,baz' > tgt
+     cat tgt.in >> tgt
+
+=item %( %)
+
+Cons includes the text of the command line in the MD5 signature for a
+build, so that targets get rebuilt if you change the command line (to
+add or remove an option, for example).  Command-line text in between
+C<%(> and C<%)>, however, will be ignored for MD5 signature calculation.
+
+Internally, Cons uses C<%(> and C<%)> around include and library
+directory options (C<-I> and C<-L> on UNIX systems, C</I> and
+C</LIBPATH> on Windows NT) to avoid rebuilds just because the directory
+list changes.  Rebuilds occur only if the changed directory list causes
+any included I<files> to change, and a changed include file is detected
+by the MD5 signature calculation on the actual file contents.
+
+=back
+
+XXX DESCRIBE THE Literal() FUNCTION, TOO XXX
+
+=head2 Expanding construction variables in file names
+
+Cons expands construction variables in the source and target file names
+passed to the various construction methods according to the expansion
+rules described above:
+
+     $env = new cons(
+	DESTDIR	=>	'programs',
+	SRCDIR	=>	'src',
+     );
+     Program $env '%DESTDIR/hello', '%SRCDIR/hello.c';
+
+This allows for flexible configuration, through the construction
+environment, of directory names, suffixes, etc.
+
+-->
+
+  <para>
+
+  An <literal>environment</literal>
+  is a collection of values that
+  can affect how a program executes.
+  &SCons; distinguishes between three
+  different types of environments
+  that can affect the behavior of &SCons; itself
+  (subject to the configuration in the &SConscript; files),
+  as well as the compilers and other tools it executes:
+
+  </para>
+
+  <variablelist>
+
+    <varlistentry>
+    <term>External Environment</term>
+
+    <listitem>
+    <para>
+
+    The <literal>external environment</literal>
+    is the set of variables in the user's environment
+    at the time the user runs &SCons.
+    These variables are available within the &SConscript; files
+    through the Python <literal>os.environ</literal> dictionary.
+    See <xref linkend="sect-external-environments"></xref>, below.
+
+    </para>
+    </listitem>
+    </varlistentry>
+
+    <varlistentry>
+    <term>&ConsEnv;</term>
+
+    <listitem>
+    <para>
+
+    A &consenv;
+    is a distinct object creating within
+    a &SConscript; file and
+    and which contains values that
+    affect how &SCons; decides
+    what action to use to build a target,
+    and even to define which targets
+    should be built from which sources.
+    One of the most powerful features of &SCons;
+    is the ability to create multiple &consenvs;,
+    including the ability to clone a new, customized
+    &consenv; from an existing &consenv;.
+    See <xref linkend="sect-construction-environments"></xref>, below.
+
+    </para>
+    </listitem>
+    </varlistentry>
+
+    <varlistentry>
+    <term>Execution Environment</term>
+
+    <listitem>
+    <para>
+
+    An <literal>execution environment</literal>
+    is the values that &SCons; sets
+    when executing an external
+    command (such as a compiler or linker)
+    to build one or more targets.
+    Note that this is not the same as
+    the <literal>external environment</literal>
+    (see above).
+    See <xref linkend="sect-execution-environments"></xref>, below.
+
+    </para>
+    </listitem>
+    </varlistentry>
+
+  </variablelist>
+
+  <para>
+
+  Unlike &Make;,  &SCons; does not automatically
+  copy or import values between different environments
+  (with the exception of explicit clones of &consenvs,
+  which inherit values from their parent).
+  This is a deliberate design choice
+  to make sure that builds are,
+  by default, repeatable regardless of
+  the values in the user's external environment.
+  This avoids a whole class of problems with builds
+  where a developer's local build works
+  because a custom variable setting
+  causes a different compiler or build option to be used,
+  but the checked-in change breaks the official build
+  because it uses different environment variable settings.
+
+  </para>
+
+  <para>
+
+  Note that the &SConscript; writer can
+  easily arrange for variables to be
+  copied or imported between environments,
+  and this is often very useful
+  (or even downright necessary)
+  to make it easy for developers
+  to customize the build in appropriate ways.
+  The point is <emphasis>not</emphasis>
+  that copying variables between different environments
+  is evil and must always be avoided.
+  Instead, it should be up to the
+  implementer of the build system
+  to make conscious choices
+  about how and when to import
+  a variable from one environment to another,
+  making informed decisions about
+  striking the right balance
+  between making the build
+  repeatable on the one hand
+  and convenient to use on the other.
+
+  </para>
+
+  <section id="sect-external-environments">
+  <title>Using Values From the External Environment</title>
+
+  <para>
+
+  The <literal>external environment</literal>
+  variable settings that
+  the user has in force
+  when executing &SCons;
+  are available through the normal Python
+  <envar>os.environ</envar>
+  dictionary.
+  This means that you must add an
+  <literal>import os</literal> statement
+  to any &SConscript; file
+  in which you want to use
+  values from the user's external environment.
+
+  </para>
+
+   <scons_example name="ex1">
+     <file name="SConstruct" printme="1">
+     import os
+     </file>
+     <file name="foo.c">
+    int main() { }
+     </file>
+   </scons_example>
+
+  <para>
+
+  More usefully, you can use the
+  <envar>os.environ</envar>
+  dictionary in your &SConscript;
+  files to initialize &consenvs;
+  with values from the user's external environment.
+  See the next section,
+  <xref linkend="sect-construction-environments"></xref>,
+  for information on how to do this.
+
+  </para>
+
+  </section>
+
+  <section id="sect-construction-environments">
+  <title>Construction Environments</title>
+
+    <para>
+
+      It is rare that all of the software in a large,
+      complicated system needs to be built the same way.
+      For example, different source files may need different options
+      enabled on the command line,
+      or different executable programs need to be linked
+      with different libraries.
+      &SCons; accommodates these different build
+      requirements by allowing you to create and
+      configure multiple &consenvs;
+      that control how the software is built.
+      A &consenv; is an object
+      that has a number of associated
+      &consvars;, each with a name and a value.
+      (A construction environment also has an attached
+      set of &Builder; methods,
+      about which we'll learn more later.)
+
+    </para>
+
+    <section>
+    <title>Creating a &ConsEnv;:  the &Environment; Function</title>
+
+      <para>
+
+        A &consenv; is created by the &Environment; method:
+
+      </para>
+
+       <sconstruct>
+         env = Environment()
+       </sconstruct>
+
+      <para>
+
+        By default, &SCons; initializes every
+        new construction environment
+        with a set of &consvars;
+        based on the tools that it finds on your system,
+        plus the default set of builder methods
+        necessary for using those tools.
+        The construction variables
+        are initialized with values describing
+        the C compiler,
+        the Fortran compiler,
+        the linker,
+        etc.,
+        as well as the command lines to invoke them.
+
+      </para>
+
+      <para>
+
+        When you initialize a construction environment
+        you can set the values of the
+        environment's &consvars;
+        to control how a program is built.
+        For example:
+
+      </para>
+
+       <scons_example name="ex1">
+         <file name="SConstruct" printme="1">
+         env = Environment(CC = 'gcc',
+                           CCFLAGS = '-O2')
+
+         env.Program('foo.c')
+         </file>
+         <file name="foo.c">
+        int main() { }
+         </file>
+       </scons_example>
+
+      <para>
+
+        The construction environment in this example
+        is still initialized with the same default
+        construction variable values,
+        except that the user has explicitly specified use of the
+        GNU C compiler &gcc;,
+        and further specifies that the <literal>-O2</literal>
+        (optimization level two)
+        flag should be used when compiling the object file.
+        In other words, the explicit initializations of
+        &cv-link-CC; and &cv-link-CCFLAGS;
+        override the default values in the newly-created
+        construction environment.
+        So a run from this example would look like:
+
+      </para>
+
+      <scons_output example="ex1">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+    </section>
+
+    <section>
+    <title>Fetching Values From a &ConsEnv;</title>
+
+      <para>
+
+      You can fetch individual construction variables
+      using the normal syntax
+      for accessing individual named items in a Python dictionary:
+
+      </para>
+
+      <scons_example name="ex6">
+        <file name="SConstruct" printme="1">
+         env = Environment()
+         print "CC is:", env['CC']
+        </file>
+      </scons_example>
+
+      <para>
+
+      This example &SConstruct; file doesn't build anything,
+      but because it's actually a Python script,
+      it will print the value of &cv-link-CC; for us:
+
+      </para>
+
+      <scons_output example="ex6">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      A construction environment, however,
+      is actually an object with associated methods, etc.
+      If you want to have direct access to only the
+      dictionary of construction variables,
+      you can fetch this using the &Dictionary; method:
+
+      </para>
+
+      <scons_example name="ex6b">
+         <file name="SConstruct" printme="1">
+         env = Environment(FOO = 'foo', BAR = 'bar')
+         dict = env.Dictionary()
+         for key in ['OBJSUFFIX', 'LIBSUFFIX', 'PROGSUFFIX']:
+             print "key = %s, value = %s" % (key, dict[key])
+         </file>
+      </scons_Example>
+
+      <para>
+
+      This &SConstruct; file
+      will print the specified dictionary items for us on POSIX
+      systems as follows:
+
+      </para>
+
+      <scons_output example="ex6b" os="posix">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      And on Windows:
+
+      </para>
+
+      <scons_output example="ex6b" os="win32">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      If you want to loop and print the values of
+      all of the construction variables in a construction environment,
+      the Python code to do that in sorted order might look something like:
+
+      </para>
+
+      <sconstruct>
+         env = Environment()
+         dict = env.Dictionary()
+         keys = dict.keys()
+         keys.sort()
+         for key in keys:
+             print "construction variable = '%s', value = '%s'" % (key, dict[key])
+      </sconstruct>
+
+    </section>
+
+    <section>
+    <title>Expanding Values From a &ConsEnv;:  the &subst; Method</title>
+
+      <para>
+
+      Another way to get information from
+      a construction environment.
+      is to use the &subst; method
+      on a string containing <literal>$</literal> expansions
+      of construction variable names.
+      As a simple example,
+      the example from the previous
+      section that used
+      <literal>env['CC']</literal>
+      to fetch the value of &cv-link-CC;
+      could also be written as:
+
+      </para>
+
+      <sconstruct>
+        env = Environment()
+        print "CC is:", env.subst('$CC')
+      </sconstruct>
+
+      <para>
+
+      One advantage of using
+      &subst; to expand strings is
+      that construction variables
+      in the result get re-expanded until
+      there are no expansions left in the string.
+      So a simple fetch of a value like
+      &cv-link-CCCOM;:
+
+      </para>
+
+      <sconstruct>
+        env = Environment(CCFLAGS = '-DFOO')
+        print "CCCOM is:", env['CCCOM']
+      </sconstruct>
+
+      <para>
+
+      Will print the unexpanded value of &cv-CCCOM;,
+      showing us the construction
+      variables that still need to be expanded:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q</userinput>
+        CCCOM is: $CC $CCFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
+        scons: `.' is up to date.
+      </screen>
+
+      <para>
+
+      Calling the &subst; method on <varname>$CCOM</varname>,
+      however:
+
+      </para>
+
+      <sconstruct>
+        env = Environment(CCFLAGS = '-DFOO')
+        print "CCCOM is:", env.subst('$CCCOM')
+      </sconstruct>
+
+      <para>
+
+      Will recursively expand all of
+      the construction variables prefixed
+      with <literal>$</literal> (dollar signs),
+      showing us the final output:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q</userinput>
+        CCCOM is: gcc -DFOO -c -o
+        scons: `.' is up to date.
+      </screen>
+
+      <para>
+
+      Note that because we're not expanding this
+      in the context of building something
+      there are no target or source files
+      for &cv-link-TARGET; and &cv-link-SOURCES; to expand.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Controlling the Default &ConsEnv;:  the &DefaultEnvironment; Function</title>
+
+      <para>
+
+      All of the &Builder; functions that we've introduced so far,
+      like &Program; and &Library;,
+      actually use a default &consenv;
+      that contains settings
+      for the various compilers
+      and other tools that
+      &SCons; configures by default,
+      or otherwise knows about
+      and has discovered on your system.
+      The goal of the default construction environment
+      is to make many configurations to "just work"
+      to build software using
+      readily available tools
+      with a minimum of configuration changes.
+
+      </para>
+
+      <para>
+
+      You can, however, control the settings
+      in the default contstruction environment
+      by using the &DefaultEnvironment; function
+      to initialize various settings:
+
+      </para>
+
+      <sconstruct>
+
+      DefaultEnvironment(CC = '/usr/local/bin/gcc')
+
+      </sconstruct>
+
+      <para>
+
+      When configured as above,
+      all calls to the &Program;
+      or &Object; Builder
+      will build object files with the
+      <filename>/usr/local/bin/gcc</filename>
+      compiler.
+
+      </para>
+
+      <para>
+
+      Note that the &DefaultEnvironment; function
+      returns the initialized
+      default construction environment object,
+      which can then be manipulated like any
+      other construction environment.
+      So the following
+      would be equivalent to the
+      previous example,
+      setting the &cv-CC;
+      variable to <filename>/usr/local/bin/gcc</filename>
+      but as a separate step after
+      the default construction environment has been initialized:
+
+      </para>
+
+      <sconstruct>
+
+      env = DefaultEnvironment()
+      env['CC'] = '/usr/local/bin/gcc'
+
+      </sconstruct>
+
+      <para>
+
+      One very common use of the &DefaultEnvironment; function
+      is to speed up &SCons; initialization.
+      As part of trying to make most default
+      configurations "just work,"
+      &SCons; will actually
+      search the local system for installed
+      compilers and other utilities.
+      This search can take time,
+      especially on systems with
+      slow or networked file systems.
+      If you know which compiler(s) and/or
+      other utilities you want to configure,
+      you can control the search
+      that &SCons; performs
+      by specifying some specific
+      tool modules with which to
+      initialize the default construction environment:
+
+      </para>
+
+      <sconstruct>
+
+      env = DefaultEnvironment(tools = ['gcc', 'gnulink'],
+                               CC = '/usr/local/bin/gcc')
+
+      </sconstruct>
+
+      <para>
+
+      So the above example would tell &SCons;
+      to explicitly configure the default environment
+      to use its normal GNU Compiler and GNU Linker settings
+      (without having to search for them,
+      or any other utilities for that matter),
+      and specifically to use the compiler found at
+      <filename>/usr/local/bin/gcc</filename>.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Multiple &ConsEnvs;</title>
+
+      <para>
+
+      The real advantage of construction environments
+      is that you can create as many different construction
+      environments as you need,
+      each tailored to a different way to build
+      some piece of software or other file.
+      If, for example, we need to build
+      one program with the <literal>-O2</literal> flag
+      and another with the <literal>-g</literal> (debug) flag,
+      we would do this like so:
+
+      </para>
+
+      <scons_example name="ex2">
+        <file name="SConstruct" printme="1">
+         opt = Environment(CCFLAGS = '-O2')
+         dbg = Environment(CCFLAGS = '-g')
+
+         opt.Program('foo', 'foo.c')
+
+         dbg.Program('bar', 'bar.c')
+        </file>
+        <file name="foo.c">
+        int main() { }
+        </file>
+        <file name="bar.c">
+        int main() { }
+        </file>
+      </scons_example>
+
+      <scons_output example="ex2">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      We can even use multiple construction environments to build
+      multiple versions of a single program.
+      If you do this by simply trying to use the
+      &b-link-Program; builder with both environments, though,
+      like this:
+
+      </para>
+
+      <scons_example name="ex3">
+        <file name="SConstruct" printme="1">
+         opt = Environment(CCFLAGS = '-O2')
+         dbg = Environment(CCFLAGS = '-g')
+
+         opt.Program('foo', 'foo.c')
+
+         dbg.Program('foo', 'foo.c')
+        </file>
+        <file name="foo.c">
+        int main() { }
+        </file>
+      </scons_example>
+
+      <para>
+
+      Then &SCons; generates the following error:
+
+      </para>
+
+      <scons_output example="ex3">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      This is because the two &b-Program; calls have
+      each implicitly told &SCons; to generate an object file named
+      <filename>foo.o</filename>,
+      one with a &cv-link-CCFLAGS; value of
+      <literal>-O2</literal>
+      and one with a &cv-link-CCFLAGS; value of
+      <literal>-g</literal>.
+      &SCons; can't just decide that one of them
+      should take precedence over the other,
+      so it generates the error.
+      To avoid this problem,
+      we must explicitly specify
+      that each environment compile
+      <filename>foo.c</filename>
+      to a separately-named object file
+      using the &b-link-Object; builder, like so:
+
+      </para>
+
+      <scons_example name="ex4">
+        <file name="SConstruct" printme="1">
+         opt = Environment(CCFLAGS = '-O2')
+         dbg = Environment(CCFLAGS = '-g')
+
+         o = opt.Object('foo-opt', 'foo.c')
+         opt.Program(o)
+
+         d = dbg.Object('foo-dbg', 'foo.c')
+         dbg.Program(d)
+        </file>
+        <file name="foo.c">
+        int main() { }
+        </file>
+      </scons_example>
+
+      <para>
+
+      Notice that each call to the &b-Object; builder
+      returns a value,
+      an internal &SCons; object that
+      represents the object file that will be built.
+      We then use that object
+      as input to the &b-Program; builder.
+      This avoids having to specify explicitly
+      the object file name in multiple places,
+      and makes for a compact, readable
+      &SConstruct; file.
+      Our &SCons; output then looks like:
+
+      </para>
+
+      <scons_output example="ex4">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+    </section>
+
+    <section>
+    <title>Making Copies of &ConsEnvs;:  the &Clone; Method</title>
+
+      <para>
+
+      Sometimes you want more than one construction environment
+      to share the same values for one or more variables.
+      Rather than always having to repeat all of the common
+      variables when you create each construction environment,
+      you can use the &Clone; method
+      to create a copy of a construction environment.
+
+      </para>
+
+      <para>
+
+      Like the &Environment; call that creates a construction environment,
+      the &Clone; method takes &consvar; assignments,
+      which will override the values in the copied construction environment.
+      For example, suppose we want to use &gcc;
+      to create three versions of a program,
+      one optimized, one debug, and one with neither.
+      We could do this by creating a "base" construction environment
+      that sets &cv-link-CC; to &gcc;,
+      and then creating two copies,
+      one which sets &cv-link-CCFLAGS; for optimization
+      and the other which sets &cv-CCFLAGS; for debugging:
+
+      </para>
+
+      <scons_example name="ex5">
+        <file name="SConstruct" printme="1">
+         env = Environment(CC = 'gcc')
+         opt = env.Clone(CCFLAGS = '-O2')
+         dbg = env.Clone(CCFLAGS = '-g')
+
+         env.Program('foo', 'foo.c')
+
+         o = opt.Object('foo-opt', 'foo.c')
+         opt.Program(o)
+
+         d = dbg.Object('foo-dbg', 'foo.c')
+         dbg.Program(d)
+        </file>
+        <file name="foo.c">
+        int main() { }
+        </file>
+      </scons_example>
+
+      <para>
+
+      Then our output would look like:
+
+      </para>
+
+      <scons_output example="ex5">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+    </section>
+
+    <section>
+    <title>Replacing Values:  the &Replace; Method</title>
+
+      <para>
+
+      You can replace existing construction variable values
+      using the &Replace; method:
+
+      </para>
+
+      <scons_example name="Replace1">
+        <file name="SConstruct" printme="1">
+         env = Environment(CCFLAGS = '-DDEFINE1')
+         env.Replace(CCFLAGS = '-DDEFINE2')
+         env.Program('foo.c')
+        </file>
+        <file name="foo.c">
+        int main() { }
+        </file>
+      </scons_example>
+
+      <para>
+
+      The replacing value
+      (<literal>-DDEFINE2</literal> in the above example)
+      completely replaces the value in the
+      construction environment:
+
+      </para>
+
+      <scons_output example="Replace1">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      You can safely call &Replace;
+      for construction variables that
+      don't exist in the construction environment:
+
+      </para>
+
+      <scons_example name="Replace-nonexistent">
+        <file name="SConstruct" printme="1">
+         env = Environment()
+         env.Replace(NEW_VARIABLE = 'xyzzy')
+         print "NEW_VARIABLE =", env['NEW_VARIABLE']
+        </file>
+      </scons_example>
+
+      <para>
+
+      In this case,
+      the construction variable simply
+      gets added to the construction environment:
+
+      </para>
+
+      <scons_output example="Replace-nonexistent">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Because the variables
+      aren't expanded until the construction environment
+      is actually used to build the targets,
+      and because &SCons; function and method calls
+      are order-independent,
+      the last replacement "wins"
+      and is used to build all targets,
+      regardless of the order in which
+      the calls to Replace() are
+      interspersed with calls to
+      builder methods:
+
+      </para>
+
+      <scons_example name="Replace2">
+        <file name="SConstruct" printme="1">
+         env = Environment(CCFLAGS = '-DDEFINE1')
+         print "CCFLAGS =", env['CCFLAGS']
+         env.Program('foo.c')
+
+         env.Replace(CCFLAGS = '-DDEFINE2')
+         print "CCFLAGS =", env['CCFLAGS']
+         env.Program('bar.c')
+        </file>
+        <file name="foo.c">
+        int main() { }
+        </file>
+        <file name="bar.c">
+        int main() { }
+        </file>
+      </scons_example>
+
+      <para>
+
+      The timing of when the replacement
+      actually occurs relative
+      to when the targets get built
+      becomes apparent
+      if we run &scons; without the <literal>-Q</literal>
+      option:
+
+      </para>
+
+      <scons_output example="Replace2">
+         <scons_output_command>scons</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Because the replacement occurs while
+      the &SConscript; files are being read,
+      the &cv-link-CCFLAGS;
+      variable has already been set to
+      <literal>-DDEFINE2</literal>
+      by the time the &foo_o; target is built,
+      even though the call to the &Replace;
+      method does not occur until later in
+      the &SConscript; file.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Setting Values Only If They're Not Already Defined:  the &SetDefault; Method</title>
+
+      <para>
+
+      Sometimes it's useful to be able to specify
+      that a construction variable should be
+      set to a value only if the construction environment
+      does not already have that variable defined
+      You can do this with the &SetDefault; method,
+      which behaves similarly to the <function>set_default</function>
+      method of Python dictionary objects:
+
+      </para>
+
+      <sconstruct>
+      env.SetDefault(SPECIAL_FLAG = '-extra-option')
+      </sconstruct>
+
+      <para>
+
+      This is especially useful
+      when writing your own <literal>Tool</literal> modules
+      to apply variables to construction environments.
+      <!--
+      See <xref linkend="chap-tool-modules"></xref>
+      for more information about writing
+      Tool modules.
+      -->
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Appending to the End of Values:  the &Append; Method</title>
+
+      <para>
+
+      You can append a value to
+      an existing construction variable
+      using the &Append; method:
+
+      </para>
+
+      <scons_example name="ex8">
+        <file name="SConstruct" printme="1">
+         env = Environment(CCFLAGS = ['-DMY_VALUE'])
+         env.Append(CCFLAGS = ['-DLAST'])
+         env.Program('foo.c')
+        </file>
+        <file name="foo.c">
+        int main() { }
+        </file>
+      </scons_example>
+
+      <para>
+
+      &SCons; then supplies both the <literal>-DMY_VALUE</literal> and
+      <literal>-DLAST</literal> flags when compiling the object file:
+
+      </para>
+
+      <scons_output example="ex8">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      If the construction variable doesn't already exist,
+      the &Append; method will create it:
+
+      </para>
+
+      <scons_example name="Append-nonexistent">
+        <file name="SConstruct" printme="1">
+         env = Environment()
+         env.Append(NEW_VARIABLE = 'added')
+         print "NEW_VARIABLE =", env['NEW_VARIABLE']
+        </file>
+      </scons_example>
+
+      <para>
+
+      Which yields:
+
+      </para>
+
+      <scons_output example="Append-nonexistent">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Note that the &Append; function tries to be "smart"
+      about how the new value is appended to the old value.
+      If both are strings, the previous and new strings
+      are simply concatenated.
+      Similarly, if both are lists,
+      the lists are concatenated.
+      If, however, one is a string and the other is a list,
+      the string is added as a new element to the list.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Appending Unique Values:  the &AppendUnique; Method</title>
+
+      <para>
+
+      Some times it's useful to add a new value
+      only if the existing construction variable
+      doesn't already contain the value.
+      This can be done using the &AppendUnique; method:
+
+      </para>
+
+      <sconstruct>
+      env.AppendUnique(CCFLAGS=['-g'])
+      </sconstruct>
+
+      <para>
+
+      In the above example,
+      the <literal>-g</literal> would be added
+      only if the &cv-CCFLAGS; variable
+      does not already contain a <literal>-g</literal> value.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Appending to the Beginning of Values:  the &Prepend; Method</title>
+
+      <para>
+
+      You can append a value to the beginning of
+      an existing construction variable
+      using the &Prepend; method:
+
+      </para>
+
+      <scons_example name="ex9">
+        <file name="SConstruct" printme="1">
+         env = Environment(CCFLAGS = ['-DMY_VALUE'])
+         env.Prepend(CCFLAGS = ['-DFIRST'])
+         env.Program('foo.c')
+        </file>
+        <file name="foo.c">
+        int main() { }
+        </file>
+      </scons_example>
+
+      <para>
+
+      &SCons; then supplies both the <literal>-DFIRST</literal> and
+      <literal>-DMY_VALUE</literal> flags when compiling the object file:
+
+      </para>
+
+      <scons_output example="ex9">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      If the construction variable doesn't already exist,
+      the &Prepend; method will create it:
+
+      </para>
+
+      <scons_example name="Prepend-nonexistent">
+        <file name="SConstruct" printme="1">
+         env = Environment()
+         env.Prepend(NEW_VARIABLE = 'added')
+         print "NEW_VARIABLE =", env['NEW_VARIABLE']
+        </file>
+      </scons_example>
+
+      <para>
+
+      Which yields:
+
+      </para>
+
+      <scons_output example="Prepend-nonexistent">
+         <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Like the &Append; function,
+      the &Prepend; function tries to be "smart"
+      about how the new value is appended to the old value.
+      If both are strings, the previous and new strings
+      are simply concatenated.
+      Similarly, if both are lists,
+      the lists are concatenated.
+      If, however, one is a string and the other is a list,
+      the string is added as a new element to the list.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Prepending Unique Values:  the &PrependUnique; Method</title>
+
+      <para>
+
+      Some times it's useful to add a new value
+      to the beginning of a construction variable
+      only if the existing value
+      doesn't already contain the to-be-added value.
+      This can be done using the &PrependUnique; method:
+
+      </para>
+
+      <sconstruct>
+      env.PrependUnique(CCFLAGS=['-g'])
+      </sconstruct>
+
+      <para>
+
+      In the above example,
+      the <literal>-g</literal> would be added
+      only if the &cv-CCFLAGS; variable
+      does not already contain a <literal>-g</literal> value.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <section id="sect-execution-environments">
+  <title>Controlling the Execution Environment for Issued Commands</title>
+
+    <para>
+
+      When &SCons; builds a target file,
+      it does not execute the commands with
+      the same external environment
+      that you used to execute &SCons;.
+      Instead, it uses the dictionary
+      stored in the &cv-link-ENV; construction variable
+      as the external environment
+      for executing commands.
+
+    </para>
+
+    <para>
+
+      The most important ramification of this behavior
+      is that the &PATH; environment variable,
+      which controls where the operating system
+      will look for commands and utilities,
+      is not the same as in the external environment
+      from which you called &SCons;.
+      This means that &SCons; will not, by default,
+      necessarily find all of the tools
+      that you can execute from the command line.
+
+    </para>
+
+    <para>
+
+      The default value of the &PATH; environment variable
+      on a POSIX system
+      is <literal>/usr/local/bin:/bin:/usr/bin</literal>.
+      The default value of the &PATH; environment variable
+      on a Windows system comes from the Windows registry
+      value for the command interpreter.
+      If you want to execute any commands--compilers, linkers, etc.--that
+      are not in these default locations,
+      you need to set the &PATH; value
+      in the &cv-ENV; dictionary
+      in your construction environment.
+
+    </para>
+
+    <para>
+
+      The simplest way to do this is to initialize explicitly
+      the value when you create the construction environment;
+      this is one way to do that:
+
+    </para>
+
+    <sconstruct>
+      path = ['/usr/local/bin', '/bin', '/usr/bin']
+      env = Environment(ENV = {'PATH' : path})
+    </sconstruct>
+
+    <para>
+
+    Assign a dictionary to the &cv-ENV;
+    construction variable in this way
+    completely resets the external environment
+    so that the only variable that will be
+    set when external commands are executed
+    will be the &PATH; value.
+    If you want to use the rest of
+    the values in &cv-ENV; and only
+    set the value of &PATH;,
+    the most straightforward way is probably:
+
+    </para>
+
+    <sconstruct>
+      env['ENV']['PATH'] = ['/usr/local/bin', '/bin', '/usr/bin']
+    </sconstruct>
+
+    <para>
+
+    Note that &SCons; does allow you to define
+    the directories in the &PATH; in a string,
+    separated by the pathname-separator character
+    for your system (':' on POSIX systems, ';' on Windows):
+
+    </para>
+
+    <sconstruct>
+      env['ENV']['PATH'] = '/usr/local/bin:/bin:/usr/bin'
+    </sconstruct>
+
+    <para>
+
+    But doing so makes your &SConscript; file less portable,
+    (although in this case that may not be a huge concern
+    since the directories you list are likley system-specific, anyway).
+
+    </para>
+
+    <!--
+
+    <scons_example name="ex1">
+      <file name="SConstruct" printme="1">
+      env = Environment()
+      env.Command('foo', [], '__ROOT__/usr/bin/printenv.py')
+      </file>
+      <file name="__ROOT__/usr/bin/printenv.py" chmod="0755">
+      #!/usr/bin/env python
+      import os
+      import sys
+      if len(sys.argv) > 1:
+          keys = sys.argv[1:]
+      else:
+          keys = os.environ.keys()
+          keys.sort()
+      for key in keys:
+          print "    " + key + "=" + os.environ[key]
+      </file>
+    </scons_example>
+
+    <para>
+
+    </para>
+
+    <scons_output example="ex1">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <section>
+    <title>Propagating &PATH; From the External Environment</title>
+
+      <para>
+
+      You may want to propagate the external &PATH;
+      to the execution environment for commands.
+      You do this by initializing the &PATH;
+      variable with the &PATH; value from
+      the <literal>os.environ</literal>
+      dictionary,
+      which is Python's way of letting you
+      get at the external environment:
+
+      </para>
+
+      <sconstruct>
+        import os
+        env = Environment(ENV = {'PATH' : os.environ['PATH']})
+      </sconstruct>
+
+      <para>
+
+      Alternatively, you may find it easier
+      to just propagate the entire external
+      environment to the execution environment
+      for commands.
+      This is simpler to code than explicity
+      selecting the &PATH; value:
+
+      </para>
+
+      <sconstruct>
+        import os
+        env = Environment(ENV = os.environ)
+      </sconstruct>
+
+      <para>
+
+      Either of these will guarantee that
+      &SCons; will be able to execute
+      any command that you can execute from the command line.
+      The drawback is that the build can behave
+      differently if it's run by people with
+      different &PATH; values in their environment--for example,
+      if both the <literal>/bin</literal> and
+      <literal>/usr/local/bin</literal> directories
+      have different &cc; commands,
+      then which one will be used to compile programs
+      will depend on which directory is listed
+      first in the user's &PATH; variable.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Adding to <varname>PATH</varname> Values in the Execution Environment</title>
+
+      <para>
+
+      One of the most common requirements
+      for manipulating a variable in the execution environment
+      is to add one or more custom directories to a search
+      like the <envar>$PATH</envar> variable on Linux or POSIX systems,
+      or the <envar>%PATH%</envar> variable on Windows,
+      so that a locally-installed compiler or other utility
+      can be found when &SCons; tries to execute it to update a target.
+      &SCons; provides &PrependENVPath; and &AppendENVPath; functions
+      to make adding things to execution variables convenient.
+      You call these functions by specifying the variable
+      to which you want the value added,
+      and then value itself.
+      So to add some <filename>/usr/local</filename> directories
+      to the <envar>$PATH</envar> and <envar>$LIB</envar> variables,
+      you might:
+
+      </para>
+
+      <sconstruct>
+        env = Environment(ENV = os.environ)
+        env.PrependENVPath('PATH', '/usr/local/bin')
+        env.AppendENVPath('LIB', '/usr/local/lib')
+      </sconstruct>
+
+      <para>
+
+      Note that the added values are strings,
+      and if you want to add multiple directories to
+      a variable like <envar>$PATH</envar>,
+      you must include the path separate character
+      (<literal>:</literal> on Linux or POSIX,
+      <literal>;</literal> on Windows)
+      in the string.
+
+      </para>
+
+    </section>
+
+  </section>
diff --git a/doc/user/environments.xml b/doc/user/environments.xml
new file mode 100644
index 0000000..b9a60b9
--- /dev/null
+++ b/doc/user/environments.xml
@@ -0,0 +1,1684 @@
+<!--
+
+     Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+     Permission is hereby granted, free of charge, to any person obtaining
+     a copy of this software and associated documentation files (the
+     "Software"), to deal in the Software without restriction, including
+     without limitation the rights to use, copy, modify, merge, publish,
+     distribute, sublicense, and/or sell copies of the Software, and to
+     permit persons to whom the Software is furnished to do so, subject to
+     the following conditions:
+
+     The above copyright notice and this permission notice shall be included
+     in all copies or substantial portions of the Software.
+
+     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+     KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+     WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+     LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+     OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 More on construction environments
+
+As previously mentioned, a B<construction environment> is an object that
+has a set of keyword/value pairs and a set of methods, and which is used
+to tell Cons how target files should be built.  This section describes
+how Cons uses and expands construction environment values to control its
+build behavior.
+
+=head2 Construction variable expansion
+
+Construction variables from a construction environment are expanded
+by preceding the keyword with a C<%> (percent sign):
+
+     Construction variables:
+	XYZZY => 'abracadabra',
+
+     The string:  "The magic word is:  %XYZZY!"
+     expands to:  "The magic word is:  abracadabra!"
+
+A construction variable name may be surrounded by C<{> and C<}> (curly
+braces), which are stripped as part of the expansion.  This can
+sometimes be necessary to separate a variable expansion from trailing
+alphanumeric characters:
+
+     Construction variables:
+	OPT    => 'value1',
+	OPTION => 'value2',
+
+     The string:  "%OPT %{OPT}ION %OPTION %{OPTION}"
+     expands to:  "value1 value1ION value2 value2"
+
+Construction variable expansion is recursive, that is, a string
+containing C<%->expansions after substitution will be re-expanded until
+no further substitutions can be made:
+
+     Construction variables:
+	STRING => 'The result is:  %FOO',
+	FOO    => '%BAR',
+	BAR    => 'final value',
+
+     The string:  "The string says:  %STRING"
+     expands to:  "The string says:  The result is:  final value"
+
+If a construction variable is not defined in an environment, then the
+null string is substituted:
+
+     Construction variables:
+	FOO => 'value1',
+	BAR => 'value2',
+
+     The string:  "%FOO <%NO_VARIABLE> %BAR"
+     expands to:  "value1 <> value2"
+
+A doubled C<%%> will be replaced by a single C<%>:
+
+     The string:  "Here is a percent sign:  %%"
+     expands to:  "Here is a percent sign: %"
+
+=head2 Default construction variables
+
+When you specify no arguments when creating a new construction
+environment:
+
+     $env = new cons();
+
+Cons creates a reference to a new, default construction
+environment. This contains a number of construction variables and some
+methods. At the present writing, the default construction variables on a
+UNIX system are:
+
+     CC            => 'cc',
+     CFLAGS        => '',
+     CCCOM         => '%CC %CFLAGS %_IFLAGS -c %< -o %>',
+     CXX           => '%CC',
+     CXXFLAGS      => '%CFLAGS',
+     CXXCOM        => '%CXX %CXXFLAGS %_IFLAGS -c %< -o %>',
+     INCDIRPREFIX  => '-I',
+     INCDIRSUFFIX  => '',
+     LINK          => '%CXX',
+     LINKCOM       => '%LINK %LDFLAGS -o %> %< %_LDIRS %LIBS',
+     LINKMODULECOM => '%LD -r -o %> %<',
+     LIBDIRPREFIX  => '-L',
+     LIBDIRSUFFIX  => '',
+     AR		=> 'ar',
+     ARFLAGS	=> 'r',
+     ARCOM		=> ['%AR %ARFLAGS %> %<', '%RANLIB %>'],
+     RANLIB	=> 'ranlib',
+     AS		=> 'as',
+     ASFLAGS	=> '',
+     ASCOM		=> '%AS %ASFLAGS %< -o %>',
+     LD		=> 'ld',
+     LDFLAGS	=> '',
+     PREFLIB	=> 'lib',
+     SUFLIB	=> '.a',
+     SUFLIBS	=> '.so:.a',
+     SUFOBJ	=> '.o',
+     SIGNATURE     => [ '*' => 'build' ],
+     ENV		=> { 'PATH' => '/bin:/usr/bin' },
+
+
+And on a Windows system (Windows NT), the default construction variables
+are (unless the default rule style is set using the B<DefaultRules>
+method):
+
+     CC		=> 'cl',
+     CFLAGS	=> '/nologo',
+     CCCOM		=> '%CC %CFLAGS %_IFLAGS /c %< /Fo%>',
+     CXXCOM        => '%CXX %CXXFLAGS %_IFLAGS /c %< /Fo%>',
+     INCDIRPREFIX  => '/I',
+     INCDIRSUFFIX  => '',
+     LINK          => 'link',
+     LINKCOM       => '%LINK %LDFLAGS /out:%> %< %_LDIRS %LIBS',
+     LINKMODULECOM => '%LD /r /o %> %<',
+     LIBDIRPREFIX  => '/LIBPATH:',
+     LIBDIRSUFFIX  => '',
+     AR            => 'lib',
+     ARFLAGS       => '/nologo ',
+     ARCOM         => "%AR %ARFLAGS /out:%> %<",
+     RANLIB        => '',
+     LD            => 'link',
+     LDFLAGS       => '/nologo ',
+     PREFLIB       => '',
+     SUFEXE	=> '.exe',
+     SUFLIB	=> '.lib',
+     SUFLIBS	=> '.dll:.lib',
+     SUFOBJ	=> '.obj',
+     SIGNATURE     => [ '*' => 'build' ],
+
+These variables are used by the various methods associated with the
+environment. In particular, any method that ultimately invokes an external
+command will substitute these variables into the final command, as
+appropriate. For example, the C<Objects> method takes a number of source
+files and arranges to derive, if necessary, the corresponding object
+files:
+
+     Objects $env 'foo.c', 'bar.c';
+
+This will arrange to produce, if necessary, F<foo.o> and F<bar.o>. The
+command invoked is simply C<%CCCOM>, which expands, through substitution,
+to the appropriate external command required to build each object. The
+substitution rules will be discussed in detail in the next section.
+
+The construction variables are also used for other purposes. For example,
+C<CPPPATH> is used to specify a colon-separated path of include
+directories. These are intended to be passed to the C preprocessor and are
+also used by the C-file scanning machinery to determine the dependencies
+involved in a C Compilation.
+
+Variables beginning with underscore are created by various methods,
+and should normally be considered ``internal'' variables. For example,
+when a method is called which calls for the creation of an object from
+a C source, the variable C<_IFLAGS> is created: this corresponds to the
+C<-I> switches required by the C compiler to represent the directories
+specified by C<CPPPATH>.
+
+Note that, for any particular environment, the value of a variable is set
+once, and then never reset (to change a variable, you must create a new
+environment. Methods are provided for copying existing environments for this
+purpose). Some internal variables, such as C<_IFLAGS> are created on demand,
+but once set, they remain fixed for the life of the environment.
+
+The C<CFLAGS>, C<LDFLAGS>, and C<ARFLAGS> variables all supply a place
+for passing options to the compiler, loader, and archiver, respectively.
+
+The C<INCDIRPREFIX> and C<INCDIRSUFFIX> variables specify option
+strings to be appended to the beginning and end, respectively, of each
+include directory so that the compiler knows where to find F<.h> files.
+Similarly, the C<LIBDIRPREFIX> and C<LIBDIRSUFFIX> variables specify the
+option string to be appended to the beginning of and end, respectively,
+of each directory that the linker should search for libraries.
+
+Another variable, C<ENV>, is used to determine the system environment during
+the execution of an external command. By default, the only environment
+variable that is set is C<PATH>, which is the execution path for a UNIX
+command. For the utmost reproducibility, you should really arrange to set
+your own execution path, in your top-level F<Construct> file (or perhaps by
+importing an appropriate construction package with the Perl C<use>
+command). The default variables are intended to get you off the ground.
+
+=head2 Expanding variables in construction commands
+
+Within a construction command, construction variables will be expanded
+according to the rules described above.  In addition to normal variable
+expansion from the construction environment, construction commands also
+expand the following pseudo-variables to insert the specific input and
+output files in the command line that will be executed:
+
+=over 10
+
+=item %>
+
+The target file name.  In a multi-target command, this expands to the
+first target mentioned.)
+
+=item %0
+
+Same as C<%E<gt>>.
+
+=item %1, %2, ..., %9
+
+These refer to the first through ninth input file, respectively.
+
+=item %E<lt>
+
+The full set of input file names. If any of these have been used
+anywhere else in the current command line (via C<%1>, C<%2>, etc.), then
+those will be deleted from the list provided by C<%E<lt>>. Consider the
+following command found in a F<Conscript> file in the F<test> directory:
+
+     Command $env 'tgt', qw(foo bar baz), qq(
+	echo %< -i %1 > %>
+	echo %< -i %2 >> %>
+	echo %< -i %3 >> %>
+     );
+
+If F<tgt> needed to be updated, then this would result in the execution of
+the following commands, assuming that no remapping has been established for
+the F<test> directory:
+
+     echo test/bar test/baz -i test/foo > test/tgt
+     echo test/foo test/baz -i test/bar >> test/tgt
+     echo test/foo test/bar -i test/baz >> test/tgt
+
+=back
+
+Any of the above pseudo-variables may be followed immediately by one of
+the following suffixes to select a portion of the expanded path name:
+
+     :a    the absolute path to the file name
+     :b    the directory plus the file name stripped of any suffix
+     :d    the directory
+     :f    the file name
+     :s    the file name suffix
+     :F    the file name stripped of any suffix
+     :S    the absolute path path to a Linked source file
+
+Continuing with the above example, C<%E<lt>:f> would expand to C<foo bar baz>,
+and C<%E<gt>:d> would expand to C<test>.
+
+There are additional C<%> elements which affect the command line(s):
+
+=over 10
+
+=item %[ %]
+
+It is possible to programmatically rewrite part of the command by
+enclosing part of it between C<%[> and C<%]>.  This will call the
+construction variable named as the first word enclosed in the brackets
+as a Perl code reference; the results of this call will be used to
+replace the contents of the brackets in the command line.  For example,
+given an existing input file named F<tgt.in>:
+
+     @keywords = qw(foo bar baz);
+     $env = new cons(X_COMMA => sub { join(",", @_) });
+     Command $env 'tgt', 'tgt.in', qq(
+	echo '# Keywords: %[X_COMMA @keywords %]' > %>
+	cat %< >> %>
+     );
+
+This will execute:
+
+     echo '# Keywords: foo,bar,baz' > tgt
+     cat tgt.in >> tgt
+
+=item %( %)
+
+Cons includes the text of the command line in the MD5 signature for a
+build, so that targets get rebuilt if you change the command line (to
+add or remove an option, for example).  Command-line text in between
+C<%(> and C<%)>, however, will be ignored for MD5 signature calculation.
+
+Internally, Cons uses C<%(> and C<%)> around include and library
+directory options (C<-I> and C<-L> on UNIX systems, C</I> and
+C</LIBPATH> on Windows NT) to avoid rebuilds just because the directory
+list changes.  Rebuilds occur only if the changed directory list causes
+any included I<files> to change, and a changed include file is detected
+by the MD5 signature calculation on the actual file contents.
+
+=back
+
+XXX DESCRIBE THE Literal() FUNCTION, TOO XXX
+
+=head2 Expanding construction variables in file names
+
+Cons expands construction variables in the source and target file names
+passed to the various construction methods according to the expansion
+rules described above:
+
+     $env = new cons(
+	DESTDIR	=>	'programs',
+	SRCDIR	=>	'src',
+     );
+     Program $env '%DESTDIR/hello', '%SRCDIR/hello.c';
+
+This allows for flexible configuration, through the construction
+environment, of directory names, suffixes, etc.
+
+-->
+
+  <para>
+
+  An <literal>environment</literal>
+  is a collection of values that
+  can affect how a program executes.
+  &SCons; distinguishes between three
+  different types of environments
+  that can affect the behavior of &SCons; itself
+  (subject to the configuration in the &SConscript; files),
+  as well as the compilers and other tools it executes:
+
+  </para>
+
+  <variablelist>
+
+    <varlistentry>
+    <term>External Environment</term>
+
+    <listitem>
+    <para>
+
+    The <literal>external environment</literal>
+    is the set of variables in the user's environment
+    at the time the user runs &SCons;.
+    These variables are available within the &SConscript; files
+    through the Python <literal>os.environ</literal> dictionary.
+    See <xref linkend="sect-external-environments"></xref>, below.
+
+    </para>
+    </listitem>
+    </varlistentry>
+
+    <varlistentry>
+    <term>&ConsEnv;</term>
+
+    <listitem>
+    <para>
+
+    A &consenv;
+    is a distinct object creating within
+    a &SConscript; file and
+    and which contains values that
+    affect how &SCons; decides
+    what action to use to build a target,
+    and even to define which targets
+    should be built from which sources.
+    One of the most powerful features of &SCons;
+    is the ability to create multiple &consenvs;,
+    including the ability to clone a new, customized
+    &consenv; from an existing &consenv;.
+    See <xref linkend="sect-construction-environments"></xref>, below.
+
+    </para>
+    </listitem>
+    </varlistentry>
+
+    <varlistentry>
+    <term>Execution Environment</term>
+
+    <listitem>
+    <para>
+
+    An <literal>execution environment</literal>
+    is the values that &SCons; sets
+    when executing an external
+    command (such as a compiler or linker)
+    to build one or more targets.
+    Note that this is not the same as
+    the <literal>external environment</literal>
+    (see above).
+    See <xref linkend="sect-execution-environments"></xref>, below.
+
+    </para>
+    </listitem>
+    </varlistentry>
+
+  </variablelist>
+
+  <para>
+
+  Unlike &Make;,  &SCons; does not automatically
+  copy or import values between different environments
+  (with the exception of explicit clones of &consenvs;,
+  which inherit values from their parent).
+  This is a deliberate design choice
+  to make sure that builds are,
+  by default, repeatable regardless of
+  the values in the user's external environment.
+  This avoids a whole class of problems with builds
+  where a developer's local build works
+  because a custom variable setting
+  causes a different compiler or build option to be used,
+  but the checked-in change breaks the official build
+  because it uses different environment variable settings.
+
+  </para>
+
+  <para>
+
+  Note that the &SConscript; writer can
+  easily arrange for variables to be
+  copied or imported between environments,
+  and this is often very useful
+  (or even downright necessary)
+  to make it easy for developers
+  to customize the build in appropriate ways.
+  The point is <emphasis>not</emphasis>
+  that copying variables between different environments
+  is evil and must always be avoided.
+  Instead, it should be up to the
+  implementer of the build system
+  to make conscious choices
+  about how and when to import
+  a variable from one environment to another,
+  making informed decisions about
+  striking the right balance
+  between making the build
+  repeatable on the one hand
+  and convenient to use on the other.
+
+  </para>
+
+  <section id="sect-external-environments">
+  <title>Using Values From the External Environment</title>
+
+  <para>
+
+  The <literal>external environment</literal>
+  variable settings that
+  the user has in force
+  when executing &SCons;
+  are available through the normal Python
+  <envar>os.environ</envar>
+  dictionary.
+  This means that you must add an
+  <literal>import os</literal> statement
+  to any &SConscript; file
+  in which you want to use
+  values from the user's external environment.
+
+  </para>
+
+   <programlisting>
+     import os
+   </programlisting>
+
+  <para>
+
+  More usefully, you can use the
+  <envar>os.environ</envar>
+  dictionary in your &SConscript;
+  files to initialize &consenvs;
+  with values from the user's external environment.
+  See the next section,
+  <xref linkend="sect-construction-environments"></xref>,
+  for information on how to do this.
+
+  </para>
+
+  </section>
+
+  <section id="sect-construction-environments">
+  <title>Construction Environments</title>
+
+    <para>
+
+      It is rare that all of the software in a large,
+      complicated system needs to be built the same way.
+      For example, different source files may need different options
+      enabled on the command line,
+      or different executable programs need to be linked
+      with different libraries.
+      &SCons; accommodates these different build
+      requirements by allowing you to create and
+      configure multiple &consenvs;
+      that control how the software is built.
+      A &consenv; is an object
+      that has a number of associated
+      &consvars;, each with a name and a value.
+      (A construction environment also has an attached
+      set of &Builder; methods,
+      about which we'll learn more later.)
+
+    </para>
+
+    <section>
+    <title>Creating a &ConsEnv;:  the &Environment; Function</title>
+
+      <para>
+
+        A &consenv; is created by the &Environment; method:
+
+      </para>
+
+       <programlisting>
+         env = Environment()
+       </programlisting>
+
+      <para>
+
+        By default, &SCons; initializes every
+        new construction environment
+        with a set of &consvars;
+        based on the tools that it finds on your system,
+        plus the default set of builder methods
+        necessary for using those tools.
+        The construction variables
+        are initialized with values describing
+        the C compiler,
+        the Fortran compiler,
+        the linker,
+        etc.,
+        as well as the command lines to invoke them.
+
+      </para>
+
+      <para>
+
+        When you initialize a construction environment
+        you can set the values of the
+        environment's &consvars;
+        to control how a program is built.
+        For example:
+
+      </para>
+
+       <programlisting>
+     import os
+
+         env = Environment(CC = 'gcc',
+                           CCFLAGS = '-O2')
+
+         env.Program('foo.c')
+       </programlisting>
+
+      <para>
+
+        The construction environment in this example
+        is still initialized with the same default
+        construction variable values,
+        except that the user has explicitly specified use of the
+        GNU C compiler &gcc;,
+        and further specifies that the <literal>-O2</literal>
+        (optimization level two)
+        flag should be used when compiling the object file.
+        In other words, the explicit initializations of
+        &cv-link-CC; and &cv-link-CCFLAGS;
+        override the default values in the newly-created
+        construction environment.
+        So a run from this example would look like:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         gcc -o foo.o -c -O2 foo.c
+         gcc -o foo foo.o
+      </screen>
+
+    </section>
+
+    <section>
+    <title>Fetching Values From a &ConsEnv;</title>
+
+      <para>
+
+      You can fetch individual construction variables
+      using the normal syntax
+      for accessing individual named items in a Python dictionary:
+
+      </para>
+
+      <programlisting>
+         env = Environment()
+         print "CC is:", env['CC']
+      </programlisting>
+
+      <para>
+
+      This example &SConstruct; file doesn't build anything,
+      but because it's actually a Python script,
+      it will print the value of &cv-link-CC; for us:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         CC is: cc
+         scons: `.' is up to date.
+      </screen>
+
+      <para>
+
+      A construction environment, however,
+      is actually an object with associated methods, etc.
+      If you want to have direct access to only the
+      dictionary of construction variables,
+      you can fetch this using the &Dictionary; method:
+
+      </para>
+
+      <programlisting>
+         env = Environment(FOO = 'foo', BAR = 'bar')
+         dict = env.Dictionary()
+         for key in ['OBJSUFFIX', 'LIBSUFFIX', 'PROGSUFFIX']:
+             print "key = %s, value = %s" % (key, dict[key])
+      </programlisting>
+
+      <para>
+
+      This &SConstruct; file
+      will print the specified dictionary items for us on POSIX
+      systems as follows:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         key = OBJSUFFIX, value = .o
+         key = LIBSUFFIX, value = .a
+         key = PROGSUFFIX, value = 
+         scons: `.' is up to date.
+      </screen>
+
+      <para>
+
+      And on Windows:
+
+      </para>
+
+      <screen>
+         C:\><userinput>scons -Q</userinput>
+         
+         scons: warning: No installed VCs
+         File "&lt;stdin&gt;", line 67, in __call__
+         
+         scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+         File "&lt;stdin&gt;", line 67, in __call__
+         
+         scons: warning: No installed VCs
+         File "&lt;stdin&gt;", line 67, in __call__
+         
+         scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+         File "&lt;stdin&gt;", line 67, in __call__
+         key = OBJSUFFIX, value = .obj
+         key = LIBSUFFIX, value = .lib
+         key = PROGSUFFIX, value = .exe
+         scons: `.' is up to date.
+      </screen>
+
+      <para>
+
+      If you want to loop and print the values of
+      all of the construction variables in a construction environment,
+      the Python code to do that in sorted order might look something like:
+
+      </para>
+
+      <programlisting>
+         env = Environment()
+         dict = env.Dictionary()
+         keys = dict.keys()
+         keys.sort()
+         for key in keys:
+             print "construction variable = '%s', value = '%s'" % (key, dict[key])
+      </programlisting>
+
+    </section>
+
+    <section>
+    <title>Expanding Values From a &ConsEnv;:  the &subst; Method</title>
+
+      <para>
+
+      Another way to get information from
+      a construction environment.
+      is to use the &subst; method
+      on a string containing <literal>$</literal> expansions
+      of construction variable names.
+      As a simple example,
+      the example from the previous
+      section that used
+      <literal>env['CC']</literal>
+      to fetch the value of &cv-link-CC;
+      could also be written as:
+
+      </para>
+
+      <programlisting>
+        env = Environment()
+        print "CC is:", env.subst('$CC')
+      </programlisting>
+
+      <para>
+
+      One advantage of using
+      &subst; to expand strings is
+      that construction variables
+      in the result get re-expanded until
+      there are no expansions left in the string.
+      So a simple fetch of a value like
+      &cv-link-CCCOM;:
+
+      </para>
+
+      <programlisting>
+        env = Environment(CCFLAGS = '-DFOO')
+        print "CCCOM is:", env['CCCOM']
+      </programlisting>
+
+      <para>
+
+      Will print the unexpanded value of &cv-CCCOM;,
+      showing us the construction
+      variables that still need to be expanded:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q</userinput>
+        CCCOM is: $CC $CCFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
+        scons: `.' is up to date.
+      </screen>
+
+      <para>
+
+      Calling the &subst; method on <varname>$CCOM</varname>,
+      however:
+
+      </para>
+
+      <programlisting>
+        env = Environment(CCFLAGS = '-DFOO')
+        print "CCCOM is:", env.subst('$CCCOM')
+      </programlisting>
+
+      <para>
+
+      Will recursively expand all of
+      the construction variables prefixed
+      with <literal>$</literal> (dollar signs),
+      showing us the final output:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q</userinput>
+        CCCOM is: gcc -DFOO -c -o
+        scons: `.' is up to date.
+      </screen>
+
+      <para>
+
+      Note that because we're not expanding this
+      in the context of building something
+      there are no target or source files
+      for &cv-link-TARGET; and &cv-link-SOURCES; to expand.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Controlling the Default &ConsEnv;:  the &DefaultEnvironment; Function</title>
+
+      <para>
+
+      All of the &Builder; functions that we've introduced so far,
+      like &Program; and &Library;,
+      actually use a default &consenv;
+      that contains settings
+      for the various compilers
+      and other tools that
+      &SCons; configures by default,
+      or otherwise knows about
+      and has discovered on your system.
+      The goal of the default construction environment
+      is to make many configurations to "just work"
+      to build software using
+      readily available tools
+      with a minimum of configuration changes.
+
+      </para>
+
+      <para>
+
+      You can, however, control the settings
+      in the default contstruction environment
+      by using the &DefaultEnvironment; function
+      to initialize various settings:
+
+      </para>
+
+      <programlisting>
+
+      DefaultEnvironment(CC = '/usr/local/bin/gcc')
+
+      </programlisting>
+
+      <para>
+
+      When configured as above,
+      all calls to the &Program;
+      or &Object; Builder
+      will build object files with the
+      <filename>/usr/local/bin/gcc</filename>
+      compiler.
+
+      </para>
+
+      <para>
+
+      Note that the &DefaultEnvironment; function
+      returns the initialized
+      default construction environment object,
+      which can then be manipulated like any
+      other construction environment.
+      So the following
+      would be equivalent to the
+      previous example,
+      setting the &cv-CC;
+      variable to <filename>/usr/local/bin/gcc</filename>
+      but as a separate step after
+      the default construction environment has been initialized:
+
+      </para>
+
+      <programlisting>
+
+      env = DefaultEnvironment()
+      env['CC'] = '/usr/local/bin/gcc'
+
+      </programlisting>
+
+      <para>
+
+      One very common use of the &DefaultEnvironment; function
+      is to speed up &SCons; initialization.
+      As part of trying to make most default
+      configurations "just work,"
+      &SCons; will actually
+      search the local system for installed
+      compilers and other utilities.
+      This search can take time,
+      especially on systems with
+      slow or networked file systems.
+      If you know which compiler(s) and/or
+      other utilities you want to configure,
+      you can control the search
+      that &SCons; performs
+      by specifying some specific
+      tool modules with which to
+      initialize the default construction environment:
+
+      </para>
+
+      <programlisting>
+
+      env = DefaultEnvironment(tools = ['gcc', 'gnulink'],
+                               CC = '/usr/local/bin/gcc')
+
+      </programlisting>
+
+      <para>
+
+      So the above example would tell &SCons;
+      to explicitly configure the default environment
+      to use its normal GNU Compiler and GNU Linker settings
+      (without having to search for them,
+      or any other utilities for that matter),
+      and specifically to use the compiler found at
+      <filename>/usr/local/bin/gcc</filename>.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Multiple &ConsEnvs;</title>
+
+      <para>
+
+      The real advantage of construction environments
+      is that you can create as many different construction
+      environments as you need,
+      each tailored to a different way to build
+      some piece of software or other file.
+      If, for example, we need to build
+      one program with the <literal>-O2</literal> flag
+      and another with the <literal>-g</literal> (debug) flag,
+      we would do this like so:
+
+      </para>
+
+      <programlisting>
+         opt = Environment(CCFLAGS = '-O2')
+         dbg = Environment(CCFLAGS = '-g')
+
+         opt.Program('foo', 'foo.c')
+
+         dbg.Program('bar', 'bar.c')
+      </programlisting>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         cc -o bar.o -c -g bar.c
+         cc -o bar bar.o
+         cc -o foo.o -c -O2 foo.c
+         cc -o foo foo.o
+      </screen>
+
+      <para>
+
+      We can even use multiple construction environments to build
+      multiple versions of a single program.
+      If you do this by simply trying to use the
+      &b-link-Program; builder with both environments, though,
+      like this:
+
+      </para>
+
+      <programlisting>
+         opt = Environment(CCFLAGS = '-O2')
+         dbg = Environment(CCFLAGS = '-g')
+
+         opt.Program('foo', 'foo.c')
+
+         dbg.Program('foo', 'foo.c')
+      </programlisting>
+
+      <para>
+
+      Then &SCons; generates the following error:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         
+         scons: warning: Two different environments were specified for target foo.o,
+         	but they appear to have the same action: CCCom(target, source, env)
+         File "/home/my/project/SConstruct", line 6, in ?
+         
+         scons: warning: Two different environments were specified for target foo,
+         	but they appear to have the same action: Cat(target, source, env)
+         File "/home/my/project/SConstruct", line 6, in ?
+         cc -o foo.o -c -g foo.c
+         cc -o foo foo.o
+      </screen>
+
+      <para>
+
+      This is because the two &b-Program; calls have
+      each implicitly told &SCons; to generate an object file named
+      <filename>foo.o</filename>,
+      one with a &cv-link-CCFLAGS; value of
+      <literal>-O2</literal>
+      and one with a &cv-link-CCFLAGS; value of
+      <literal>-g</literal>.
+      &SCons; can't just decide that one of them
+      should take precedence over the other,
+      so it generates the error.
+      To avoid this problem,
+      we must explicitly specify
+      that each environment compile
+      <filename>foo.c</filename>
+      to a separately-named object file
+      using the &b-link-Object; builder, like so:
+
+      </para>
+
+      <programlisting>
+         opt = Environment(CCFLAGS = '-O2')
+         dbg = Environment(CCFLAGS = '-g')
+
+         o = opt.Object('foo-opt', 'foo.c')
+         opt.Program(o)
+
+         d = dbg.Object('foo-dbg', 'foo.c')
+         dbg.Program(d)
+      </programlisting>
+
+      <para>
+
+      Notice that each call to the &b-Object; builder
+      returns a value,
+      an internal &SCons; object that
+      represents the object file that will be built.
+      We then use that object
+      as input to the &b-Program; builder.
+      This avoids having to specify explicitly
+      the object file name in multiple places,
+      and makes for a compact, readable
+      &SConstruct; file.
+      Our &SCons; output then looks like:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         cc -o foo-dbg.o -c -g foo.c
+         cc -o foo-dbg foo-dbg.o
+         cc -o foo-opt.o -c -O2 foo.c
+         cc -o foo-opt foo-opt.o
+      </screen>
+
+    </section>
+
+    <section>
+    <title>Making Copies of &ConsEnvs;:  the &Clone; Method</title>
+
+      <para>
+
+      Sometimes you want more than one construction environment
+      to share the same values for one or more variables.
+      Rather than always having to repeat all of the common
+      variables when you create each construction environment,
+      you can use the &Clone; method
+      to create a copy of a construction environment.
+
+      </para>
+
+      <para>
+
+      Like the &Environment; call that creates a construction environment,
+      the &Clone; method takes &consvar; assignments,
+      which will override the values in the copied construction environment.
+      For example, suppose we want to use &gcc;
+      to create three versions of a program,
+      one optimized, one debug, and one with neither.
+      We could do this by creating a "base" construction environment
+      that sets &cv-link-CC; to &gcc;,
+      and then creating two copies,
+      one which sets &cv-link-CCFLAGS; for optimization
+      and the other which sets &cv-CCFLAGS; for debugging:
+
+      </para>
+
+      <programlisting>
+         env = Environment(CC = 'gcc')
+         opt = env.Clone(CCFLAGS = '-O2')
+         dbg = env.Clone(CCFLAGS = '-g')
+
+         env.Program('foo', 'foo.c')
+
+         o = opt.Object('foo-opt', 'foo.c')
+         opt.Program(o)
+
+         d = dbg.Object('foo-dbg', 'foo.c')
+         dbg.Program(d)
+      </programlisting>
+
+      <para>
+
+      Then our output would look like:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         gcc -o foo.o -c foo.c
+         gcc -o foo foo.o
+         gcc -o foo-dbg.o -c -g foo.c
+         gcc -o foo-dbg foo-dbg.o
+         gcc -o foo-opt.o -c -O2 foo.c
+         gcc -o foo-opt foo-opt.o
+      </screen>
+
+    </section>
+
+    <section>
+    <title>Replacing Values:  the &Replace; Method</title>
+
+      <para>
+
+      You can replace existing construction variable values
+      using the &Replace; method:
+
+      </para>
+
+      <programlisting>
+         env = Environment(CCFLAGS = '-DDEFINE1')
+         env.Replace(CCFLAGS = '-DDEFINE2')
+         env.Program('foo.c')
+      </programlisting>
+
+      <para>
+
+      The replacing value
+      (<literal>-DDEFINE2</literal> in the above example)
+      completely replaces the value in the
+      construction environment:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         cc -o foo.o -c -DDEFINE2 foo.c
+         cc -o foo foo.o
+      </screen>
+
+      <para>
+
+      You can safely call &Replace;
+      for construction variables that
+      don't exist in the construction environment:
+
+      </para>
+
+      <programlisting>
+         env = Environment()
+         env.Replace(NEW_VARIABLE = 'xyzzy')
+         print "NEW_VARIABLE =", env['NEW_VARIABLE']
+      </programlisting>
+
+      <para>
+
+      In this case,
+      the construction variable simply
+      gets added to the construction environment:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         NEW_VARIABLE = xyzzy
+         scons: `.' is up to date.
+      </screen>
+
+      <para>
+
+      Because the variables
+      aren't expanded until the construction environment
+      is actually used to build the targets,
+      and because &SCons; function and method calls
+      are order-independent,
+      the last replacement "wins"
+      and is used to build all targets,
+      regardless of the order in which
+      the calls to Replace() are
+      interspersed with calls to
+      builder methods:
+
+      </para>
+
+      <programlisting>
+         env = Environment(CCFLAGS = '-DDEFINE1')
+         print "CCFLAGS =", env['CCFLAGS']
+         env.Program('foo.c')
+
+         env.Replace(CCFLAGS = '-DDEFINE2')
+         print "CCFLAGS =", env['CCFLAGS']
+         env.Program('bar.c')
+      </programlisting>
+
+      <para>
+
+      The timing of when the replacement
+      actually occurs relative
+      to when the targets get built
+      becomes apparent
+      if we run &scons; without the <literal>-Q</literal>
+      option:
+
+      </para>
+
+      <screen>
+         % <userinput>scons</userinput>
+         scons: Reading SConscript files ...
+         CCFLAGS = -DDEFINE1
+         CCFLAGS = -DDEFINE2
+         scons: done reading SConscript files.
+         scons: Building targets ...
+         cc -o bar.o -c -DDEFINE2 bar.c
+         cc -o bar bar.o
+         cc -o foo.o -c -DDEFINE2 foo.c
+         cc -o foo foo.o
+         scons: done building targets.
+      </screen>
+
+      <para>
+
+      Because the replacement occurs while
+      the &SConscript; files are being read,
+      the &cv-link-CCFLAGS;
+      variable has already been set to
+      <literal>-DDEFINE2</literal>
+      by the time the &foo_o; target is built,
+      even though the call to the &Replace;
+      method does not occur until later in
+      the &SConscript; file.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Setting Values Only If They're Not Already Defined:  the &SetDefault; Method</title>
+
+      <para>
+
+      Sometimes it's useful to be able to specify
+      that a construction variable should be
+      set to a value only if the construction environment
+      does not already have that variable defined
+      You can do this with the &SetDefault; method,
+      which behaves similarly to the <function>set_default</function>
+      method of Python dictionary objects:
+
+      </para>
+
+      <programlisting>
+      env.SetDefault(SPECIAL_FLAG = '-extra-option')
+      </programlisting>
+
+      <para>
+
+      This is especially useful
+      when writing your own <literal>Tool</literal> modules
+      to apply variables to construction environments.
+      <!--
+      See <xref linkend="chap-tool-modules"></xref>
+      for more information about writing
+      Tool modules.
+      -->
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Appending to the End of Values:  the &Append; Method</title>
+
+      <para>
+
+      You can append a value to
+      an existing construction variable
+      using the &Append; method:
+
+      </para>
+
+      <programlisting>
+         env = Environment(CCFLAGS = ['-DMY_VALUE'])
+         env.Append(CCFLAGS = ['-DLAST'])
+         env.Program('foo.c')
+      </programlisting>
+
+      <para>
+
+      &SCons; then supplies both the <literal>-DMY_VALUE</literal> and
+      <literal>-DLAST</literal> flags when compiling the object file:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         cc -o foo.o -c -DMY_VALUE -DLAST foo.c
+         cc -o foo foo.o
+      </screen>
+
+      <para>
+
+      If the construction variable doesn't already exist,
+      the &Append; method will create it:
+
+      </para>
+
+      <programlisting>
+         env = Environment()
+         env.Append(NEW_VARIABLE = 'added')
+         print "NEW_VARIABLE =", env['NEW_VARIABLE']
+      </programlisting>
+
+      <para>
+
+      Which yields:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         NEW_VARIABLE = added
+         scons: `.' is up to date.
+      </screen>
+
+      <para>
+
+      Note that the &Append; function tries to be "smart"
+      about how the new value is appended to the old value.
+      If both are strings, the previous and new strings
+      are simply concatenated.
+      Similarly, if both are lists,
+      the lists are concatenated.
+      If, however, one is a string and the other is a list,
+      the string is added as a new element to the list.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Appending Unique Values:  the &AppendUnique; Method</title>
+
+      <para>
+
+      Some times it's useful to add a new value
+      only if the existing construction variable
+      doesn't already contain the value.
+      This can be done using the &AppendUnique; method:
+
+      </para>
+
+      <programlisting>
+      env.AppendUnique(CCFLAGS=['-g'])
+      </programlisting>
+
+      <para>
+
+      In the above example,
+      the <literal>-g</literal> would be added
+      only if the &cv-CCFLAGS; variable
+      does not already contain a <literal>-g</literal> value.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Appending to the Beginning of Values:  the &Prepend; Method</title>
+
+      <para>
+
+      You can append a value to the beginning of
+      an existing construction variable
+      using the &Prepend; method:
+
+      </para>
+
+      <programlisting>
+         env = Environment(CCFLAGS = ['-DMY_VALUE'])
+         env.Prepend(CCFLAGS = ['-DFIRST'])
+         env.Program('foo.c')
+      </programlisting>
+
+      <para>
+
+      &SCons; then supplies both the <literal>-DFIRST</literal> and
+      <literal>-DMY_VALUE</literal> flags when compiling the object file:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         cc -o foo.o -c -DFIRST -DMY_VALUE foo.c
+         cc -o foo foo.o
+      </screen>
+
+      <para>
+
+      If the construction variable doesn't already exist,
+      the &Prepend; method will create it:
+
+      </para>
+
+      <programlisting>
+         env = Environment()
+         env.Prepend(NEW_VARIABLE = 'added')
+         print "NEW_VARIABLE =", env['NEW_VARIABLE']
+      </programlisting>
+
+      <para>
+
+      Which yields:
+
+      </para>
+
+      <screen>
+         % <userinput>scons -Q</userinput>
+         NEW_VARIABLE = added
+         scons: `.' is up to date.
+      </screen>
+
+      <para>
+
+      Like the &Append; function,
+      the &Prepend; function tries to be "smart"
+      about how the new value is appended to the old value.
+      If both are strings, the previous and new strings
+      are simply concatenated.
+      Similarly, if both are lists,
+      the lists are concatenated.
+      If, however, one is a string and the other is a list,
+      the string is added as a new element to the list.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Prepending Unique Values:  the &PrependUnique; Method</title>
+
+      <para>
+
+      Some times it's useful to add a new value
+      to the beginning of a construction variable
+      only if the existing value
+      doesn't already contain the to-be-added value.
+      This can be done using the &PrependUnique; method:
+
+      </para>
+
+      <programlisting>
+      env.PrependUnique(CCFLAGS=['-g'])
+      </programlisting>
+
+      <para>
+
+      In the above example,
+      the <literal>-g</literal> would be added
+      only if the &cv-CCFLAGS; variable
+      does not already contain a <literal>-g</literal> value.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <section id="sect-execution-environments">
+  <title>Controlling the Execution Environment for Issued Commands</title>
+
+    <para>
+
+      When &SCons; builds a target file,
+      it does not execute the commands with
+      the same external environment
+      that you used to execute &SCons;.
+      Instead, it uses the dictionary
+      stored in the &cv-link-ENV; construction variable
+      as the external environment
+      for executing commands.
+
+    </para>
+
+    <para>
+
+      The most important ramification of this behavior
+      is that the &PATH; environment variable,
+      which controls where the operating system
+      will look for commands and utilities,
+      is not the same as in the external environment
+      from which you called &SCons;.
+      This means that &SCons; will not, by default,
+      necessarily find all of the tools
+      that you can execute from the command line.
+
+    </para>
+
+    <para>
+
+      The default value of the &PATH; environment variable
+      on a POSIX system
+      is <literal>/usr/local/bin:/bin:/usr/bin</literal>.
+      The default value of the &PATH; environment variable
+      on a Windows system comes from the Windows registry
+      value for the command interpreter.
+      If you want to execute any commands--compilers, linkers, etc.--that
+      are not in these default locations,
+      you need to set the &PATH; value
+      in the &cv-ENV; dictionary
+      in your construction environment.
+
+    </para>
+
+    <para>
+
+      The simplest way to do this is to initialize explicitly
+      the value when you create the construction environment;
+      this is one way to do that:
+
+    </para>
+
+    <programlisting>
+      path = ['/usr/local/bin', '/bin', '/usr/bin']
+      env = Environment(ENV = {'PATH' : path})
+    </programlisting>
+
+    <para>
+
+    Assign a dictionary to the &cv-ENV;
+    construction variable in this way
+    completely resets the external environment
+    so that the only variable that will be
+    set when external commands are executed
+    will be the &PATH; value.
+    If you want to use the rest of
+    the values in &cv-ENV; and only
+    set the value of &PATH;,
+    the most straightforward way is probably:
+
+    </para>
+
+    <programlisting>
+      env['ENV']['PATH'] = ['/usr/local/bin', '/bin', '/usr/bin']
+    </programlisting>
+
+    <para>
+
+    Note that &SCons; does allow you to define
+    the directories in the &PATH; in a string,
+    separated by the pathname-separator character
+    for your system (':' on POSIX systems, ';' on Windows):
+
+    </para>
+
+    <programlisting>
+      env['ENV']['PATH'] = '/usr/local/bin:/bin:/usr/bin'
+    </programlisting>
+
+    <para>
+
+    But doing so makes your &SConscript; file less portable,
+    (although in this case that may not be a huge concern
+    since the directories you list are likley system-specific, anyway).
+
+    </para>
+
+    <!--
+
+    <scons_example name="ex1">
+      <file name="SConstruct" printme="1">
+      env = Environment()
+      env.Command('foo', [], '__ROOT__/usr/bin/printenv.py')
+      </file>
+      <file name="__ROOT__/usr/bin/printenv.py" chmod="0755">
+      #!/usr/bin/env python
+      import os
+      import sys
+      if len(sys.argv) > 1:
+          keys = sys.argv[1:]
+      else:
+          keys = os.environ.keys()
+          keys.sort()
+      for key in keys:
+          print "    " + key + "=" + os.environ[key]
+      </file>
+    </scons_example>
+
+    <para>
+
+    </para>
+
+    <scons_output example="ex1">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <section>
+    <title>Propagating &PATH; From the External Environment</title>
+
+      <para>
+
+      You may want to propagate the external &PATH;
+      to the execution environment for commands.
+      You do this by initializing the &PATH;
+      variable with the &PATH; value from
+      the <literal>os.environ</literal>
+      dictionary,
+      which is Python's way of letting you
+      get at the external environment:
+
+      </para>
+
+      <programlisting>
+        import os
+        env = Environment(ENV = {'PATH' : os.environ['PATH']})
+      </programlisting>
+
+      <para>
+
+      Alternatively, you may find it easier
+      to just propagate the entire external
+      environment to the execution environment
+      for commands.
+      This is simpler to code than explicity
+      selecting the &PATH; value:
+
+      </para>
+
+      <programlisting>
+        import os
+        env = Environment(ENV = os.environ)
+      </programlisting>
+
+      <para>
+
+      Either of these will guarantee that
+      &SCons; will be able to execute
+      any command that you can execute from the command line.
+      The drawback is that the build can behave
+      differently if it's run by people with
+      different &PATH; values in their environment--for example,
+      if both the <literal>/bin</literal> and
+      <literal>/usr/local/bin</literal> directories
+      have different &cc; commands,
+      then which one will be used to compile programs
+      will depend on which directory is listed
+      first in the user's &PATH; variable.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Adding to <varname>PATH</varname> Values in the Execution Environment</title>
+
+      <para>
+
+      One of the most common requirements
+      for manipulating a variable in the execution environment
+      is to add one or more custom directories to a search
+      like the <envar>$PATH</envar> variable on Linux or POSIX systems,
+      or the <envar>%PATH%</envar> variable on Windows,
+      so that a locally-installed compiler or other utility
+      can be found when &SCons; tries to execute it to update a target.
+      &SCons; provides &PrependENVPath; and &AppendENVPath; functions
+      to make adding things to execution variables convenient.
+      You call these functions by specifying the variable
+      to which you want the value added,
+      and then value itself.
+      So to add some <filename>/usr/local</filename> directories
+      to the <envar>$PATH</envar> and <envar>$LIB</envar> variables,
+      you might:
+
+      </para>
+
+      <programlisting>
+        env = Environment(ENV = os.environ)
+        env.PrependENVPath('PATH', '/usr/local/bin')
+        env.AppendENVPath('LIB', '/usr/local/lib')
+      </programlisting>
+
+      <para>
+
+      Note that the added values are strings,
+      and if you want to add multiple directories to
+      a variable like <envar>$PATH</envar>,
+      you must include the path separate character
+      (<literal>:</literal> on Linux or POSIX,
+      <literal>;</literal> on Windows)
+      in the string.
+
+      </para>
+
+    </section>
+
+  </section>
diff --git a/doc/user/errors.in b/doc/user/errors.in
new file mode 100644
index 0000000..0051953
--- /dev/null
+++ b/doc/user/errors.in
@@ -0,0 +1,41 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+   XXX
+
+ </para>
+
+ <section>
+ <title>XXX</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+ </section>
diff --git a/doc/user/errors.xml b/doc/user/errors.xml
new file mode 100644
index 0000000..0051953
--- /dev/null
+++ b/doc/user/errors.xml
@@ -0,0 +1,41 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+   XXX
+
+ </para>
+
+ <section>
+ <title>XXX</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+ </section>
diff --git a/doc/user/example.in b/doc/user/example.in
new file mode 100644
index 0000000..0051953
--- /dev/null
+++ b/doc/user/example.in
@@ -0,0 +1,41 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+   XXX
+
+ </para>
+
+ <section>
+ <title>XXX</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+ </section>
diff --git a/doc/user/example.xml b/doc/user/example.xml
new file mode 100644
index 0000000..0051953
--- /dev/null
+++ b/doc/user/example.xml
@@ -0,0 +1,41 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+   XXX
+
+ </para>
+
+ <section>
+ <title>XXX</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+ </section>
diff --git a/doc/user/factories.in b/doc/user/factories.in
new file mode 100644
index 0000000..0cea6c4
--- /dev/null
+++ b/doc/user/factories.in
@@ -0,0 +1,507 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  &SCons; provides a number of platform-independent functions,
+  called <literal>factories</literal>,
+  that perform common file system manipulations
+  like copying, moving or deleting files and directories,
+  or making directories.
+  These functions are <literal>factories</literal>
+  because they don't perform the action
+  at the time they're called,
+  they each return an &Action; object
+  that can be executed at the appropriate time.
+
+  </para>
+
+  <section>
+  <title>Copying Files or Directories:  The &Copy; Factory</title>
+
+    <para>
+
+    Suppose you want to arrange to make a copy of a file,
+    and don't have a suitable pre-existing builder.
+    <footnote>
+    <para>
+    Unfortunately, in the early days of SCons design,
+    we used the name &Copy; for the function that
+    returns a copy of the environment,
+    otherwise that would be the logical choice for
+    a Builder that copies a file or directory tree
+    to a target location.
+    </para>
+    </footnote>
+    One way would be to use the &Copy; action factory
+    in conjunction with the &Command; builder:
+
+    </para>
+
+    <scons_example name="Copy1">
+      <file name="SConstruct" printme="1">
+        Command("file.out", "file.in", Copy("$TARGET", "$SOURCE"))
+      </file>
+      <file name="file.in">file.in</file>
+    </scons_example>
+
+    <para>
+
+    Notice that the action returned by the &Copy; factory
+    will expand the &cv-link-TARGET; and &cv-link-SOURCE; strings
+    at the time &file_out; is built,
+    and that the order of the arguments
+    is the same as that of a builder itself--that is,
+    target first, followed by source:
+
+    </para>
+
+    <scons_output example="Copy1">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    You can, of course, name a file explicitly
+    instead of using &cv-TARGET; or &cv-SOURCE;:
+
+    </para>
+
+    <scons_example name="Copy2">
+      <file name="SConstruct" printme="1">
+      Command("file.out", [], Copy("$TARGET", "file.in"))
+      </file>
+      <file name="file.in">file.in</file>
+    </scons_example>
+
+    <para>
+
+    Which executes as:
+
+    </para>
+
+    <scons_output example="Copy2">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The usefulness of the &Copy; factory
+    becomes more apparent when
+    you use it in a list of actions
+    passed to the &Command; builder.
+    For example, suppose you needed to run a
+    file through a utility that only modifies files in-place,
+    and can't "pipe" input to output.
+    One solution is to copy the source file
+    to a temporary file name,
+    run the utility,
+    and then copy the modified temporary file to the target,
+    which the &Copy; factory makes extremely easy:
+
+    </para>
+
+    <scons_example name="Copy3">
+      <file name="S" printme="1">
+      Command("file.out", "file.in",
+              [
+                Copy("tempfile", "$SOURCE"),
+                "modify tempfile",
+                Copy("$TARGET", "tempfile"),
+              ])
+      </file>
+      <file name="SConstruct">
+      env = DefaultEnvironment()
+      import os
+      env['ENV']['PATH'] = env['ENV']['PATH'] + os.pathsep + os.getcwd()
+      SConscript('S')
+      </file>
+      <file name="file.in">file.in</file>
+      <file name="modify" chmod="0755">
+      touch $*
+      </file>
+    </scons_example>
+
+    <para>
+
+    The output then looks like:
+
+    </para>
+
+    <scons_output example="Copy3">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Deleting Files or Directories:  The &Delete; Factory</title>
+
+    <para>
+
+    If you need to delete a file,
+    then the &Delete; factory
+    can be used in much the same way as
+    the &Copy; factory.
+    For example, if we want to make sure that
+    the temporary file
+    in our last example doesn't exist before
+    we copy to it,
+    we could add &Delete; to the beginning
+    of the command list:
+
+    </para>
+
+    <scons_example name="Delete1">
+      <file name="S" printme="1">
+      Command("file.out", "file.in",
+              [
+                Delete("tempfile"),
+                Copy("tempfile", "$SOURCE"),
+                "modify tempfile",
+                Copy("$TARGET", "tempfile"),
+              ])
+      </file>
+      <file name="SConstruct">
+      env = DefaultEnvironment()
+      import os
+      env['ENV']['PATH'] = env['ENV']['PATH'] + os.pathsep + os.getcwd()
+      SConscript('S')
+      </file>
+      <file name="file.in">file.in</file>
+      <file name="modify" chmod="0755">
+      touch $*
+      </file>
+    </scons_example>
+
+    <para>
+
+    Which then executes as follows:
+
+    </para>
+
+    <scons_output example="Delete1">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Of course, like all of these &Action; factories,
+    the &Delete factory also expands
+    &cv-link-TARGET; and &cv-link-SOURCE; variables appropriately.
+    For example:
+
+    </para>
+
+    <scons_example name="Delete2">
+      <file name="SConstruct" printme="1">
+      Command("file.out", "file.in",
+              [
+                Delete("$TARGET"),
+                Copy("$TARGET", "$SOURCE")
+              ])
+      </file>
+      <file name="file.in">file.in</file>
+    </scons_example>
+
+    <para>
+
+    Executes as:
+
+    </para>
+
+    <scons_output example="Delete2">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Note, however, that you typically don't need to
+    call the &Delete; factory explicitly in this way;
+    by default, &SCons; deletes its target(s)
+    for you before executing any action.
+
+    </para>
+
+    <para>
+
+    One word of caution about using the &Delete; factory:
+    it has the same variable expansions available
+    as any other factory, including the &cv-SOURCE; variable.
+    Specifying <literal>Delete("$SOURCE")</literal>
+    is not something you usually want to do!
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Moving (Renaming) Files or Directories:  The &Move; Factory</title>
+
+    <para>
+
+    The &Move; factory
+    allows you to rename a file or directory.
+    For example, if we don't want to copy the temporary file,
+    we could use:
+
+    </para>
+
+    <scons_example name="Move">
+      <file name="S" printme="1">
+      Command("file.out", "file.in",
+              [
+                Copy("tempfile", "$SOURCE"),
+                "modify tempfile",
+                Move("$TARGET", "tempfile"),
+              ])
+      </file>
+      <file name="SConstruct">
+      env = DefaultEnvironment()
+      import os
+      env['ENV']['PATH'] = env['ENV']['PATH'] + os.pathsep + os.getcwd()
+      SConscript('S')
+      </file>
+      <file name="file.in">file.in</file>
+      <file name="modify" chmod="0755">
+      touch $*
+      </file>
+    </scons_example>
+
+    <para>
+
+    Which would execute as:
+
+    </para>
+
+    <scons_output example="Move">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Updating the Modification Time of a File:  The &Touch; Factory</title>
+
+    <para>
+
+    If you just need to update the
+    recorded modification time for a file,
+    use the &Touch; factory:
+
+    </para>
+
+    <scons_example name="Touch">
+      <file name="S" printme="1">
+      Command("file.out", "file.in",
+              [
+                Copy("$TARGET", "$SOURCE"),
+                Touch("$TARGET"),
+              ])
+      </file>
+      <file name="SConstruct">
+      env = DefaultEnvironment()
+      import os
+      env['ENV']['PATH'] = env['ENV']['PATH'] + os.pathsep + os.getcwd()
+      SConscript('S')
+      </file>
+      <file name="file.in">file.in</file>
+    </scons_example>
+
+    <para>
+
+    Which executes as:
+
+    </para>
+
+    <scons_output example="Touch">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Creating a Directory:  The &Mkdir; Factory</title>
+
+    <para>
+
+    If you need to create a directory,
+    use the &Mkdir; factory.
+    For example, if we need to process
+    a file in a temporary directory
+    in which the processing tool
+    will create other files that we don't care about, 
+    you could use:
+
+    </para>
+
+    <scons_example name="Mkdir">
+      <file name="S" printme="1">
+      Command("file.out", "file.in",
+              [
+                Delete("tempdir"),
+                Mkdir("tempdir"),
+                Copy("tempdir/${SOURCE.file}", "$SOURCE"),
+                "process tempdir",
+                Move("$TARGET", "tempdir/output_file"),
+                Delete("tempdir"),
+              ])
+      </file>
+      <file name="SConstruct">
+      env = DefaultEnvironment()
+      import os
+      env['ENV']['PATH'] = env['ENV']['PATH'] + os.pathsep + os.getcwd()
+      SConscript('S')
+      </file>
+      <file name="file.in">file.in</file>
+      <file name="process" chmod="0755">
+      touch $*
+      </file>
+    </scons_example>
+
+    <para>
+
+    Which executes as:
+
+    </para>
+
+    <scons_output example="Mkdir">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Changing File or Directory Permissions:  The &Chmod; Factory</title>
+
+    <para>
+
+    To change permissions on a file or directory,
+    use the &Chmod; factory.
+    The permission argument uses POSIX-style
+    permission bits and should typically
+    be expressed as an octal,
+    not decimal, number:
+
+    </para>
+
+    <scons_example name="Chmod">
+      <file name="SConstruct" printme="1">
+      Command("file.out", "file.in",
+              [
+                Copy("$TARGET", "$SOURCE"),
+                Chmod("$TARGET", 0755),
+              ])
+      </file>
+      <file name="file.in">file.in</file>
+    </scons_example>
+
+    <para>
+
+    Which executes:
+
+    </para>
+
+    <scons_output example="Chmod">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Executing an action immediately:  the &Execute; Function</title>
+
+    <para>
+
+    We've been showing you how to use &Action; factories
+    in the &Command; function.
+    You can also execute an &Action; returned by a factory
+    (or actually, any &Action;)
+    at the time the &SConscript; file is read
+    by using the &Execute; function.
+    For example, if we need to make sure that
+    a directory exists before we build any targets,
+
+    </para>
+
+    <scons_example name="Execute">
+      <file name="SConstruct" printme="1">
+      Execute(Mkdir('__ROOT__/tmp/my_temp_directory'))
+      </file>
+    </scons_example>
+
+    <para>
+
+    Notice that this will
+    create the directory while
+    the &SConscript; file is being read:
+
+    </para>
+
+    <scons_output example="Execute">
+      <scons_output_command>scons</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    If you're familiar with Python,
+    you may wonder why you would want to use this
+    instead of just calling the native Python
+    <function>os.mkdir()</function> function.
+    The advantage here is that the &Mkdir;
+    action will behave appropriately if the user
+    specifies the &SCons; <option>-n</option> or
+    <option>-q</option> options--that is,
+    it will print the action but not actually
+    make the directory when <option>-n</option> is specified,
+    or make the directory but not print the action
+    when <option>-q</option> is specified.
+
+    </para>
+
+    <para>
+
+    The &Execute; function returns the exit status
+    or return value of the underlying action being executed.
+    It will also print an error message if the action
+    fails and returns a non-zero value.
+    &SCons; will <emphasis>not</emphasis>, however,
+    actually stop the build if the action fails.
+    If you want the build to stop
+    in response to a failure in an action called by &Execute;,
+    you must do so by explicitly
+    checking the return value
+    and calling the &Exit; function
+    (or a Python equivalent):
+
+    </para>
+
+    <sconstruct>
+    if Execute(Mkdir('__ROOT__/tmp/my_temp_directory')):
+        # A problem occurred while making the temp directory.
+        Exit(1)
+    </sconstruct>
+
+  </section>
diff --git a/doc/user/factories.xml b/doc/user/factories.xml
new file mode 100644
index 0000000..17e52bd
--- /dev/null
+++ b/doc/user/factories.xml
@@ -0,0 +1,466 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  &SCons; provides a number of platform-independent functions,
+  called <literal>factories</literal>,
+  that perform common file system manipulations
+  like copying, moving or deleting files and directories,
+  or making directories.
+  These functions are <literal>factories</literal>
+  because they don't perform the action
+  at the time they're called,
+  they each return an &Action; object
+  that can be executed at the appropriate time.
+
+  </para>
+
+  <section>
+  <title>Copying Files or Directories:  The &Copy; Factory</title>
+
+    <para>
+
+    Suppose you want to arrange to make a copy of a file,
+    and don't have a suitable pre-existing builder.
+    <footnote>
+    <para>
+    Unfortunately, in the early days of SCons design,
+    we used the name &Copy; for the function that
+    returns a copy of the environment,
+    otherwise that would be the logical choice for
+    a Builder that copies a file or directory tree
+    to a target location.
+    </para>
+    </footnote>
+    One way would be to use the &Copy; action factory
+    in conjunction with the &Command; builder:
+
+    </para>
+
+    <programlisting>
+        Command("file.out", "file.in", Copy("$TARGET", "$SOURCE"))
+    </programlisting>
+
+    <para>
+
+    Notice that the action returned by the &Copy; factory
+    will expand the &cv-link-TARGET; and &cv-link-SOURCE; strings
+    at the time &file_out; is built,
+    and that the order of the arguments
+    is the same as that of a builder itself--that is,
+    target first, followed by source:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       Copy("file.out", "file.in")
+    </screen>
+
+    <para>
+
+    You can, of course, name a file explicitly
+    instead of using &cv-TARGET; or &cv-SOURCE;:
+
+    </para>
+
+    <programlisting>
+      Command("file.out", [], Copy("$TARGET", "file.in"))
+    </programlisting>
+
+    <para>
+
+    Which executes as:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      Copy("file.out", "file.in")
+    </screen>
+
+    <para>
+
+    The usefulness of the &Copy; factory
+    becomes more apparent when
+    you use it in a list of actions
+    passed to the &Command; builder.
+    For example, suppose you needed to run a
+    file through a utility that only modifies files in-place,
+    and can't "pipe" input to output.
+    One solution is to copy the source file
+    to a temporary file name,
+    run the utility,
+    and then copy the modified temporary file to the target,
+    which the &Copy; factory makes extremely easy:
+
+    </para>
+
+    <programlisting>
+      Command("file.out", "file.in",
+              [
+                Copy("tempfile", "$SOURCE"),
+                "modify tempfile",
+                Copy("$TARGET", "tempfile"),
+              ])
+    </programlisting>
+
+    <para>
+
+    The output then looks like:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      Copy("tempfile", "file.in")
+      modify tempfile
+      Copy("file.out", "tempfile")
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Deleting Files or Directories:  The &Delete; Factory</title>
+
+    <para>
+
+    If you need to delete a file,
+    then the &Delete; factory
+    can be used in much the same way as
+    the &Copy; factory.
+    For example, if we want to make sure that
+    the temporary file
+    in our last example doesn't exist before
+    we copy to it,
+    we could add &Delete; to the beginning
+    of the command list:
+
+    </para>
+
+    <programlisting>
+      Command("file.out", "file.in",
+              [
+                Delete("tempfile"),
+                Copy("tempfile", "$SOURCE"),
+                "modify tempfile",
+                Copy("$TARGET", "tempfile"),
+              ])
+    </programlisting>
+
+    <para>
+
+    Which then executes as follows:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      Delete("tempfile")
+      Copy("tempfile", "file.in")
+      modify tempfile
+      Copy("file.out", "tempfile")
+    </screen>
+
+    <para>
+
+    Of course, like all of these &Action; factories,
+    the &Delete; factory also expands
+    &cv-link-TARGET; and &cv-link-SOURCE; variables appropriately.
+    For example:
+
+    </para>
+
+    <programlisting>
+      Command("file.out", "file.in",
+              [
+                Delete("$TARGET"),
+                Copy("$TARGET", "$SOURCE")
+              ])
+    </programlisting>
+
+    <para>
+
+    Executes as:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      Delete("file.out")
+      Copy("file.out", "file.in")
+    </screen>
+
+    <para>
+
+    Note, however, that you typically don't need to
+    call the &Delete; factory explicitly in this way;
+    by default, &SCons; deletes its target(s)
+    for you before executing any action.
+
+    </para>
+
+    <para>
+
+    One word of caution about using the &Delete; factory:
+    it has the same variable expansions available
+    as any other factory, including the &cv-SOURCE; variable.
+    Specifying <literal>Delete("$SOURCE")</literal>
+    is not something you usually want to do!
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Moving (Renaming) Files or Directories:  The &Move; Factory</title>
+
+    <para>
+
+    The &Move; factory
+    allows you to rename a file or directory.
+    For example, if we don't want to copy the temporary file,
+    we could use:
+
+    </para>
+
+    <programlisting>
+      Command("file.out", "file.in",
+              [
+                Copy("tempfile", "$SOURCE"),
+                "modify tempfile",
+                Move("$TARGET", "tempfile"),
+              ])
+    </programlisting>
+
+    <para>
+
+    Which would execute as:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      Copy("tempfile", "file.in")
+      modify tempfile
+      Move("file.out", "tempfile")
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Updating the Modification Time of a File:  The &Touch; Factory</title>
+
+    <para>
+
+    If you just need to update the
+    recorded modification time for a file,
+    use the &Touch; factory:
+
+    </para>
+
+    <programlisting>
+      Command("file.out", "file.in",
+              [
+                Copy("$TARGET", "$SOURCE"),
+                Touch("$TARGET"),
+              ])
+    </programlisting>
+
+    <para>
+
+    Which executes as:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      Copy("file.out", "file.in")
+      Touch("file.out")
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Creating a Directory:  The &Mkdir; Factory</title>
+
+    <para>
+
+    If you need to create a directory,
+    use the &Mkdir; factory.
+    For example, if we need to process
+    a file in a temporary directory
+    in which the processing tool
+    will create other files that we don't care about, 
+    you could use:
+
+    </para>
+
+    <programlisting>
+      Command("file.out", "file.in",
+              [
+                Delete("tempdir"),
+                Mkdir("tempdir"),
+                Copy("tempdir/${SOURCE.file}", "$SOURCE"),
+                "process tempdir",
+                Move("$TARGET", "tempdir/output_file"),
+                Delete("tempdir"),
+              ])
+    </programlisting>
+
+    <para>
+
+    Which executes as:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      Delete("tempdir")
+      Mkdir("tempdir")
+      Copy("tempdir/file.in", "file.in")
+      process tempdir
+      Move("file.out", "tempdir/output_file")
+      scons: *** [file.out] tempdir/output_file: No such file or directory
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Changing File or Directory Permissions:  The &Chmod; Factory</title>
+
+    <para>
+
+    To change permissions on a file or directory,
+    use the &Chmod; factory.
+    The permission argument uses POSIX-style
+    permission bits and should typically
+    be expressed as an octal,
+    not decimal, number:
+
+    </para>
+
+    <programlisting>
+      Command("file.out", "file.in",
+              [
+                Copy("$TARGET", "$SOURCE"),
+                Chmod("$TARGET", 0755),
+              ])
+    </programlisting>
+
+    <para>
+
+    Which executes:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      Copy("file.out", "file.in")
+      Chmod("file.out", 0755)
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Executing an action immediately:  the &Execute; Function</title>
+
+    <para>
+
+    We've been showing you how to use &Action; factories
+    in the &Command; function.
+    You can also execute an &Action; returned by a factory
+    (or actually, any &Action;)
+    at the time the &SConscript; file is read
+    by using the &Execute; function.
+    For example, if we need to make sure that
+    a directory exists before we build any targets,
+
+    </para>
+
+    <programlisting>
+      Execute(Mkdir('/tmp/my_temp_directory'))
+    </programlisting>
+
+    <para>
+
+    Notice that this will
+    create the directory while
+    the &SConscript; file is being read:
+
+    </para>
+
+    <screen>
+      % <userinput>scons</userinput>
+      scons: Reading SConscript files ...
+      Mkdir("/tmp/my_temp_directory")
+      scons: done reading SConscript files.
+      scons: Building targets ...
+      scons: `.' is up to date.
+      scons: done building targets.
+    </screen>
+
+    <para>
+
+    If you're familiar with Python,
+    you may wonder why you would want to use this
+    instead of just calling the native Python
+    <function>os.mkdir()</function> function.
+    The advantage here is that the &Mkdir;
+    action will behave appropriately if the user
+    specifies the &SCons; <option>-n</option> or
+    <option>-q</option> options--that is,
+    it will print the action but not actually
+    make the directory when <option>-n</option> is specified,
+    or make the directory but not print the action
+    when <option>-q</option> is specified.
+
+    </para>
+
+    <para>
+
+    The &Execute; function returns the exit status
+    or return value of the underlying action being executed.
+    It will also print an error message if the action
+    fails and returns a non-zero value.
+    &SCons; will <emphasis>not</emphasis>, however,
+    actually stop the build if the action fails.
+    If you want the build to stop
+    in response to a failure in an action called by &Execute;,
+    you must do so by explicitly
+    checking the return value
+    and calling the &Exit; function
+    (or a Python equivalent):
+
+    </para>
+
+    <programlisting>
+    if Execute(Mkdir('/tmp/my_temp_directory')):
+        # A problem occurred while making the temp directory.
+        Exit(1)
+    </programlisting>
+
+  </section>
diff --git a/doc/user/file-removal.in b/doc/user/file-removal.in
new file mode 100644
index 0000000..c26f020
--- /dev/null
+++ b/doc/user/file-removal.in
@@ -0,0 +1,223 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  There are two occasions when &SCons; will,
+  by default, remove target files.
+  The first is when &SCons; determines that
+  an target file needs to be rebuilt
+  and removes the existing version of the target
+  before executing
+  The second is when &SCons; is invoked with the
+  <literal>-c</literal> option to "clean"
+  a tree of its built targets.
+
+  These behaviours can be suppressed with the
+  &Precious; and &NoClean; functions, respectively.
+
+  </para>
+
+  <section>
+  <title>Preventing target removal during build: the &Precious; Function</title>
+
+    <para>
+
+    By default, &SCons; removes targets before building them.
+    Sometimes, however, this is not what you want.
+    For example, you may want to update a library incrementally,
+    not by having it deleted and then rebuilt from all
+    of the constituent object files.
+    In such cases, you can use the
+    &Precious; method to prevent
+    &SCons; from removing the target before it is built:
+
+    </para>
+
+    <scons_example name="precious-ex1">
+      <file name="SConstruct" printme="1">
+        env = Environment(RANLIBCOM='')
+        lib = env.Library('foo', ['f1.c', 'f2.c', 'f3.c'])
+        env.Precious(lib)
+      </file>
+      <file name="f1.c">
+      int f1() { }
+      </file>
+      <file name="f2.c">
+      int f2() { }
+      </file>
+      <file name="f3.c">
+      int f3() { }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Although the output doesn't look any different,
+    &SCons; does not, in fact,
+    delete the target library before rebuilding it:
+
+    </para>
+
+    <scons_output example="precious-ex1">
+        <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    &SCons; will, however, still delete files marked as &Precious;
+    when the <literal>-c</literal> option is used.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Preventing target removal during clean: the &NoClean; Function</title>
+
+    <para>
+
+    By default, &SCons; removes all built targets when invoked
+    with the <literal>-c</literal> option to clean a source tree
+    of built targets.
+    Sometimes, however, this is not what you want.
+    For example, you may want to remove only intermediate generated files
+    (such as object files),
+    but leave the final targets
+    (the libraries)
+    untouched.
+
+    In such cases, you can use the &NoClean; method to prevent &SCons;
+    from removing a target during a clean:
+
+    </para>
+
+    <scons_example name="noclean-ex1">
+      <file name="SConstruct" printme="1">
+        env = Environment(RANLIBCOM='')
+        lib = env.Library('foo', ['f1.c', 'f2.c', 'f3.c'])
+        env.NoClean(lib)
+      </file>
+      <file name="f1.c">
+      int f1() { }
+      </file>
+      <file name="f2.c">
+      int f2() { }
+      </file>
+      <file name="f3.c">
+      int f3() { }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Notice that the <filename>libfoo.a</filename>
+    is not listed as a removed file:
+
+    </para>
+
+    <scons_output example="noclean-ex1">
+        <scons_output_command>scons -Q</scons_output_command>
+        <scons_output_command>scons -c</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Removing additional files during clean: the &Clean; Function</title>
+
+    <para>
+
+    There may be additional files that you want removed
+    when the <literal>-c</literal> option is used,
+    but which &SCons; doesn't know about
+    because they're not normal target files.
+    For example, perhaps a command you invoke
+    creates a log file as
+    part of building the target file you want.
+    You would like the log file cleaned,
+    but you don't want to have to teach
+    SCons that the command
+    "builds" two files.
+
+    </para>
+
+    <para>
+
+    You can use the &Clean; function to arrange for additional files
+    to be removed when the <literal>-c</literal> option is used.
+    Notice, however, that the &Clean; function takes two arguments,
+    and the <emphasis>second</emphasis> argument
+    is the name of the additional file you want cleaned
+    (<filename>foo.log</filename> in this example):
+
+    </para>
+
+    <scons_example name="clean-ex1">
+      <file name="S" printme="1">
+        t = Command('foo.out', 'foo.in', 'build -o $TARGET $SOURCE')
+        Clean(t, 'foo.log')
+      </file>
+      <file name="SConstruct">
+      env = DefaultEnvironment()
+      import os
+      env['ENV']['PATH'] = env['ENV']['PATH'] + os.pathsep + os.getcwd()
+      SConscript('S')
+      </file>
+      <file name="foo.in">
+      foo.in
+      </file>
+      <file name="foo.log">
+      foo.log
+      </file>
+      <file name="build" chmod="0755">
+      cat $3 > $2
+      </file>
+    </scons_example>
+
+    <para>
+
+    The first argument is the target with which you want
+    the cleaning of this additional file associated.
+    In the above example,
+    we've used the return value from the
+    &Command; function,
+    which represents the
+    <filename>foo.out</filename>
+    target.
+    Now whenever the
+    <filename>foo.out</filename> target is cleaned
+    by the <literal>-c</literal> option,
+    the <filename>foo.log</filename> file
+    will be removed as well:
+
+    </para>
+
+    <scons_output example="clean-ex1">
+        <scons_output_command>scons -Q</scons_output_command>
+        <scons_output_command>scons -Q -c</scons_output_command>
+    </scons_output>
+
+  </section>
diff --git a/doc/user/file-removal.xml b/doc/user/file-removal.xml
new file mode 100644
index 0000000..542fd38
--- /dev/null
+++ b/doc/user/file-removal.xml
@@ -0,0 +1,202 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  There are two occasions when &SCons; will,
+  by default, remove target files.
+  The first is when &SCons; determines that
+  an target file needs to be rebuilt
+  and removes the existing version of the target
+  before executing
+  The second is when &SCons; is invoked with the
+  <literal>-c</literal> option to "clean"
+  a tree of its built targets.
+
+  These behaviours can be suppressed with the
+  &Precious; and &NoClean; functions, respectively.
+
+  </para>
+
+  <section>
+  <title>Preventing target removal during build: the &Precious; Function</title>
+
+    <para>
+
+    By default, &SCons; removes targets before building them.
+    Sometimes, however, this is not what you want.
+    For example, you may want to update a library incrementally,
+    not by having it deleted and then rebuilt from all
+    of the constituent object files.
+    In such cases, you can use the
+    &Precious; method to prevent
+    &SCons; from removing the target before it is built:
+
+    </para>
+
+    <programlisting>
+        env = Environment(RANLIBCOM='')
+        lib = env.Library('foo', ['f1.c', 'f2.c', 'f3.c'])
+        env.Precious(lib)
+    </programlisting>
+
+    <para>
+
+    Although the output doesn't look any different,
+    &SCons; does not, in fact,
+    delete the target library before rebuilding it:
+
+    </para>
+
+    <screen>
+        % <userinput>scons -Q</userinput>
+        cc -o f1.o -c f1.c
+        cc -o f2.o -c f2.c
+        cc -o f3.o -c f3.c
+        ar rc libfoo.a f1.o f2.o f3.o
+    </screen>
+
+    <para>
+
+    &SCons; will, however, still delete files marked as &Precious;
+    when the <literal>-c</literal> option is used.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Preventing target removal during clean: the &NoClean; Function</title>
+
+    <para>
+
+    By default, &SCons; removes all built targets when invoked
+    with the <literal>-c</literal> option to clean a source tree
+    of built targets.
+    Sometimes, however, this is not what you want.
+    For example, you may want to remove only intermediate generated files
+    (such as object files),
+    but leave the final targets
+    (the libraries)
+    untouched.
+
+    In such cases, you can use the &NoClean; method to prevent &SCons;
+    from removing a target during a clean:
+
+    </para>
+
+    <programlisting>
+        env = Environment(RANLIBCOM='')
+        lib = env.Library('foo', ['f1.c', 'f2.c', 'f3.c'])
+        env.NoClean(lib)
+    </programlisting>
+
+    <para>
+
+    Notice that the <filename>libfoo.a</filename>
+    is not listed as a removed file:
+
+    </para>
+
+    <screen>
+        % <userinput>scons -Q</userinput>
+        cc -o f1.o -c f1.c
+        cc -o f2.o -c f2.c
+        cc -o f3.o -c f3.c
+        ar rc libfoo.a f1.o f2.o f3.o
+        % <userinput>scons -c</userinput>
+        scons: Reading SConscript files ...
+        scons: done reading SConscript files.
+        scons: Cleaning targets ...
+        Removed f1.o
+        Removed f2.o
+        Removed f3.o
+        scons: done cleaning targets.
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Removing additional files during clean: the &Clean; Function</title>
+
+    <para>
+
+    There may be additional files that you want removed
+    when the <literal>-c</literal> option is used,
+    but which &SCons; doesn't know about
+    because they're not normal target files.
+    For example, perhaps a command you invoke
+    creates a log file as
+    part of building the target file you want.
+    You would like the log file cleaned,
+    but you don't want to have to teach
+    SCons that the command
+    "builds" two files.
+
+    </para>
+
+    <para>
+
+    You can use the &Clean; function to arrange for additional files
+    to be removed when the <literal>-c</literal> option is used.
+    Notice, however, that the &Clean; function takes two arguments,
+    and the <emphasis>second</emphasis> argument
+    is the name of the additional file you want cleaned
+    (<filename>foo.log</filename> in this example):
+
+    </para>
+
+    <programlisting>
+        t = Command('foo.out', 'foo.in', 'build -o $TARGET $SOURCE')
+        Clean(t, 'foo.log')
+    </programlisting>
+
+    <para>
+
+    The first argument is the target with which you want
+    the cleaning of this additional file associated.
+    In the above example,
+    we've used the return value from the
+    &Command; function,
+    which represents the
+    <filename>foo.out</filename>
+    target.
+    Now whenever the
+    <filename>foo.out</filename> target is cleaned
+    by the <literal>-c</literal> option,
+    the <filename>foo.log</filename> file
+    will be removed as well:
+
+    </para>
+
+    <screen>
+        % <userinput>scons -Q</userinput>
+        build -o foo.out foo.in
+        % <userinput>scons -Q -c</userinput>
+        Removed foo.out
+        Removed foo.log
+    </screen>
+
+  </section>
diff --git a/doc/user/hierarchy.in b/doc/user/hierarchy.in
new file mode 100644
index 0000000..a917d10
--- /dev/null
+++ b/doc/user/hierarchy.in
@@ -0,0 +1,794 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+
+=head2 The Build command
+
+By default, Cons does not change its working directory to the directory
+containing a subsidiary F<Conscript> file it is including.  This behavior
+can be enabled for a build by specifying, in the top-level F<Construct>
+file:
+
+  Conscript_chdir 1;
+
+When enabled, Cons will change to the subsidiary F<Conscript> file's
+containing directory while reading in that file, and then change back
+to the top-level directory once the file has been processed.
+
+It is expected that this behavior will become the default in some future
+version of Cons.  To prepare for this transition, builds that expect
+Cons to remain at the top of the build while it reads in a subsidiary
+F<Conscript> file should explicitly disable this feature as follows:
+
+  Conscript_chdir 0;
+
+=head2 Relative, top-relative, and absolute file names
+
+(There is another file prefix, ``!'', that is interpreted specially by
+Cons.  See discussion of the C<Link> command, below, for details.)
+
+
+=head2 Using modules in build scripts
+
+You may pull modules into each F<Conscript> file using the normal Perl
+C<use> or C<require> statements:
+
+  use English;
+  require My::Module;
+
+Each C<use> or C<require> only affects the one F<Conscript> file in which
+it appears.  To use a module in multiple F<Conscript> files, you must
+put a C<use> or C<require> statement in each one that needs the module.
+
+
+=head2 Scope of variables
+
+The top-level F<Construct> file and all F<Conscript> files begin life in
+a common, separate Perl package.  B<Cons> controls the symbol table for
+the package so that, the symbol table for each script is empty, except
+for the F<Construct> file, which gets some of the command line arguments.
+All of the variables that are set or used, therefore, are set by the
+script itself, not by some external script.
+
+Variables can be explicitly B<imported> by a script from its parent
+script. To import a variable, it must have been B<exported> by the parent
+and initialized (otherwise an error will occur).
+
+
+=head2 The Export command
+
+The C<Export> command is used as in the following example:
+
+  $env = new cons();
+  $INCLUDE = "#export/include";
+  $LIB = "#export/lib";
+  Export qw( env INCLUDE LIB );
+  Build qw( util/Conscript );
+
+The values of the simple variables mentioned in the C<Export> list will be
+squirreled away by any subsequent C<Build> commands. The C<Export> command
+will only export Perl B<scalar> variables, that is, variables whose name
+begins with C<$>. Other variables, objects, etc. can be exported by
+reference, but all scripts will refer to the same object, and this object
+should be considered to be read-only by the subsidiary scripts and by the
+original exporting script. It's acceptable, however, to assign a new value
+to the exported scalar variable, that won't change the underlying variable
+referenced. This sequence, for example, is OK:
+
+  $env = new cons();
+  Export qw( env INCLUDE LIB );
+  Build qw( util/Conscript );
+  $env = new cons(CFLAGS => '-O');
+  Build qw( other/Conscript );
+
+It doesn't matter whether the variable is set before or after the C<Export>
+command. The important thing is the value of the variable at the time the
+C<Build> command is executed. This is what gets squirreled away. Any
+subsequent C<Export> commands, by the way, invalidate the first: you must
+mention all the variables you wish to export on each C<Export> command.
+
+
+=head2 The Import command
+
+Variables exported by the C<Export> command can be imported into subsidiary
+scripts by the C<Import> command. The subsidiary script always imports
+variables directly from the superior script. Consider this example:
+
+  Import qw( env INCLUDE );
+
+This is only legal if the parent script exported both C<$env> and
+C<$INCLUDE>. It also must have given each of these variables values. It is
+OK for the subsidiary script to only import a subset of the exported
+variables (in this example, C<$LIB>, which was exported by the previous
+example, is not imported).
+
+All the imported variables are automatically re-exported, so the sequence:
+
+  Import qw ( env INCLUDE );
+  Build qw ( beneath-me/Conscript );
+
+will supply both C<$env> and C<$INCLUDE> to the subsidiary file. If only
+C<$env> is to be exported, then the following will suffice:
+
+  Import qw ( env INCLUDE );
+  Export qw ( env );
+  Build qw ( beneath-me/Conscript );
+
+Needless to say, the variables may be modified locally before invoking
+C<Build> on the subsidiary script.
+
+=head2 Build script evaluation order
+
+The only constraint on the ordering of build scripts is that superior
+scripts are evaluated before their inferior scripts. The top-level
+F<Construct> file, for instance, is evaluated first, followed by any
+inferior scripts. This is all you really need to know about the evaluation
+order, since order is generally irrelevant. Consider the following C<Build>
+command:
+
+  Build qw(
+	drivers/display/Conscript
+	drivers/mouse/Conscript
+	parser/Conscript
+	utilities/Conscript
+  );
+
+We've chosen to put the script names in alphabetical order, simply because
+that's the most convenient for maintenance purposes. Changing the order will
+make no difference to the build.
+
+-->
+
+  <para>
+
+  The source code for large software projects
+  rarely stays in a single directory,
+  but is nearly always divided into a
+  hierarchy of directories.
+  Organizing a large software build using &SCons;
+  involves creating a hierarchy of build scripts
+  using the &SConscript; function.
+
+  </para>
+
+  <section>
+  <title>&SConscript; Files</title>
+
+    <para>
+
+    As we've already seen,
+    the build script at the top of the tree is called &SConstruct;.
+    The top-level &SConstruct; file can
+    use the &SConscript; function to
+    include other subsidiary scripts in the build.
+    These subsidiary scripts can, in turn,
+    use the &SConscript; function
+    to include still other scripts in the build.
+    By convention, these subsidiary scripts are usually
+    named &SConscript;.
+    For example, a top-level &SConstruct; file might
+    arrange for four subsidiary scripts to be included
+    in the build as follows:
+
+    </para>
+
+    <sconstruct>
+      SConscript(['drivers/display/SConscript',
+                  'drivers/mouse/SConscript',
+                  'parser/SConscript',
+                  'utilities/SConscript'])
+    </sconstruct>
+
+    <para>
+
+    In this case, the &SConstruct; file
+    lists all of the &SConscript; files in the build explicitly.
+    (Note, however, that not every directory in the tree
+    necessarily has an &SConscript; file.)
+    Alternatively, the <literal>drivers</literal>
+    subdirectory might contain an intermediate
+    &SConscript; file,
+    in which case the &SConscript; call in
+    the top-level &SConstruct; file
+    would look like:
+
+    </para>
+
+    <sconstruct>
+      SConscript(['drivers/SConscript',
+                  'parser/SConscript',
+                  'utilities/SConscript'])
+    </sconstruct>
+
+    <para>
+
+    And the subsidiary &SConscript; file in the
+    <literal>drivers</literal> subdirectory
+    would look like:
+
+    </para>
+
+    <sconstruct>
+      SConscript(['display/SConscript',
+                  'mouse/SConscript'])
+    </sconstruct>
+
+    <para>
+
+    Whether you list all of the &SConscript; files in the
+    top-level &SConstruct; file,
+    or place a subsidiary &SConscript; file in
+    intervening directories,
+    or use some mix of the two schemes,
+    is up to you and the needs of your software.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Path Names Are Relative to the &SConscript; Directory</title>
+
+    <para>
+
+    Subsidiary &SConscript; files make it easy to create a build
+    hierarchy because all of the file and directory names
+    in a subsidiary &SConscript; files are interpreted
+    relative to the directory in which the &SConscript; file lives.
+    Typically, this allows the &SConscript; file containing the
+    instructions to build a target file
+    to live in the same directory as the source files
+    from which the target will be built,
+    making it easy to update how the software is built
+    whenever files are added or deleted
+    (or other changes are made).
+
+    </para>
+
+    <para>
+
+    For example, suppose we want to build two programs
+    &prog1; and &prog2; in two separate directories
+    with the same names as the programs.
+    One typical way to do this would be
+    with a top-level &SConstruct; file like this:
+
+    </para>
+
+    <scons_example name="ex1">
+      <file name="SConstruct" printme="1">
+      SConscript(['prog1/SConscript',
+                  'prog2/SConscript'])
+      </file>
+      <file name="prog1/SConscript">
+      env = Environment()
+      env.Program('prog1', ['main.c', 'foo1.c', 'foo2.c'])
+      </file>
+      <file name="prog2/SConscript">
+      env = Environment()
+      env.Program('prog2', ['main.c', 'bar1.c', 'bar2.c'])
+      </file>
+      <directory name="prog1"></directory>
+      <file name="prog1/main.c">
+      x
+      </file>
+      <file name="prog1/foo1.c">
+      x
+      </file>
+      <file name="prog1/foo2.c">
+      x
+      </file>
+      <directory name="prog2"></directory>
+      <file name="prog2/main.c">
+      x
+      </file>
+      <file name="prog2/bar1.c">
+      x
+      </file>
+      <file name="prog2/bar2.c">
+      x
+      </file>
+    </scons_example>
+
+    <para>
+
+    And subsidiary &SConscript; files that look like this:
+
+    </para>
+
+    <scons_example_file example="ex1" name="prog1/SConscript">
+    </scons_example_file>
+
+    <para>
+
+    And this:
+
+    </para>
+
+    <scons_example_file example="ex1" name="prog2/SConscript">
+    </scons_example_file>
+
+    <para>
+
+    Then, when we run &SCons; in the top-level directory,
+    our build looks like:
+
+    </para>
+
+    <scons_output example="ex1">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Notice the following:
+
+    First, you can have files with the same names
+    in multiple directories, like main.c in the above example.
+
+    Second, unlike standard recursive use of &Make;,
+    &SCons; stays in the top-level directory
+    (where the &SConstruct; file lives)
+    and issues commands that use the path names
+    from the top-level directory to the
+    target and source files within the hierarchy.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Top-Level Path Names in Subsidiary &SConscript; Files</title>
+
+    <para>
+
+    If you need to use a file from another directory,
+    it's sometimes more convenient to specify
+    the path to a file in another directory
+    from the top-level &SConstruct; directory,
+    even when you're using that file in
+    a subsidiary &SConscript; file in a subdirectory.
+    You can tell &SCons; to interpret a path name
+    as relative to the top-level &SConstruct; directory,
+    not the local directory of the &SConscript; file,
+    by appending a &hash; (hash mark)
+    to the beginning of the path name:
+
+    </para>
+
+    <scons_example name="ex2">
+       <file name="SConstruct">
+       SConscript('src/prog/SConscript')
+       </file>
+       <file name="src/prog/SConscript" printme="1">
+       env = Environment()
+       env.Program('prog', ['main.c', '#lib/foo1.c', 'foo2.c'])
+       </file>
+       <file name="src/prog/main.c">
+       x
+       </file>
+       <file name="lib/foo1.c">
+       x
+       </file>
+       <file name="src/prog/foo2.c">
+       x
+       </file>
+    </scons_example>
+
+    <para>
+
+    In this example,
+    the <literal>lib</literal> directory is
+    directly underneath the top-level &SConstruct; directory.
+    If the above &SConscript; file is in a subdirectory
+    named <literal>src/prog</literal>,
+    the output would look like:
+
+    </para>
+
+    <scons_output example="ex2">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    (Notice that the <literal>lib/foo1.o</literal> object file
+    is built in the same directory as its source file.
+    See <xref linkend="chap-separate"></xref>, below,
+    for information about
+    how to build the object file in a different subdirectory.)
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Absolute Path Names</title>
+
+    <para>
+
+    Of course, you can always specify
+    an absolute path name for a file--for example:
+
+    </para>
+
+    <scons_example name="ex3">
+       <file name="SConstruct">
+       SConscript('src/prog/SConscript')
+       </file>
+       <file name="src/prog/SConscript" printme="1">
+       env = Environment()
+       env.Program('prog', ['main.c', '__ROOT__/usr/joe/lib/foo1.c', 'foo2.c'])
+       </file>
+       <file name="src/prog/main.c">
+       x
+       </file>
+       <file name="__ROOT__/usr/joe/lib/foo1.c">
+       x
+       </file>
+       <file name="src/prog/foo2.c">
+       x
+       </file>
+    </scons_example>
+
+    <para>
+
+    Which, when executed, would yield:
+
+    </para>
+
+    <scons_output example="ex3">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    (As was the case with top-relative path names,
+    notice that the <literal>/usr/joe/lib/foo1.o</literal> object file
+    is built in the same directory as its source file.
+    See <xref linkend="chap-separate"></xref>, below,
+    for information about
+    how to build the object file in a different subdirectory.)
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Sharing Environments (and Other Variables) Between &SConscript; Files</title>
+
+    <para>
+
+    In the previous example,
+    each of the subsidiary &SConscript; files
+    created its own construction environment
+    by calling &Environment; separately.
+    This obviously works fine,
+    but if each program must be built
+    with the same construction variables,
+    it's cumbersome and error-prone to initialize
+    separate construction environments
+    in the same way over and over in each subsidiary
+    &SConscript; file.
+
+    </para>
+
+    <para>
+
+    &SCons; supports the ability to <emphasis>export</emphasis> variables
+    from a parent &SConscript; file
+    to its subsidiary &SConscript; files,
+    which allows you to share common initialized
+    values throughout your build hierarchy.
+
+    </para>
+
+    <section>
+    <title>Exporting Variables</title>
+
+      <para>
+
+      There are two ways to export a variable,
+      such as a construction environment,
+      from an &SConscript; file,
+      so that it may be used by other &SConscript; files.
+      First, you can call the &Export;
+      function with a list of variables,
+      or a string of white-space separated variable names.
+      Each call to &Export; adds one
+      or more variables to a global list
+      of variables that are available for import
+      by other &SConscript; files.
+
+      </para>
+
+      <sconstruct>
+        env = Environment()
+        Export('env')
+      </sconstruct>
+
+      <para>
+
+      You may export more than one variable name at a time:
+
+      </para>
+
+      <sconstruct>
+        env = Environment()
+        debug = ARGUMENTS['debug']
+        Export('env', 'debug')
+      </sconstruct>
+
+      <para>
+
+      Because white space is not legal in Python variable names,
+      the &Export; function will even automatically split
+      a string into separate names for you:
+
+      </para>
+
+      <sconstruct>
+        Export('env debug')
+      </sconstruct>
+
+      <para>
+
+      Second, you can specify a list of
+      variables to export as a second argument
+      to the &SConscript; function call:
+
+      </para>
+
+      <sconstruct>
+        SConscript('src/SConscript', 'env')
+      </sconstruct>
+
+      <para>
+
+      Or as the &exports; keyword argument:
+
+      </para>
+
+      <sconstruct>
+        SConscript('src/SConscript', exports='env')
+      </sconstruct>
+
+      <para>
+
+      These calls export the specified variables
+      to only the listed &SConscript; files.
+      You may, however, specify more than one
+      &SConscript; file in a list:
+
+      </para>
+
+      <sconstruct>
+        SConscript(['src1/SConscript',
+                    'src2/SConscript'], exports='env')
+      </sconstruct>
+
+      <para>
+
+      This is functionally equivalent to
+      calling the &SConscript; function
+      multiple times with the same &exports; argument,
+      one per &SConscript; file.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Importing Variables</title>
+
+      <para>
+
+      Once a variable has been exported from a calling
+      &SConscript; file,
+      it may be used in other &SConscript; files
+      by calling the &Import; function:
+
+      </para>
+
+      <sconstruct>
+        Import('env')
+        env.Program('prog', ['prog.c'])
+      </sconstruct>
+
+      <para>
+
+      The &Import; call makes the <literal>env</literal> construction
+      environment available to the &SConscript; file,
+      after which the variable can be used to build
+      programs, libraries, etc.
+
+      </para>
+
+      <para>
+
+      Like the &Export; function,
+      the &Import; function can be used
+      with multiple variable names:
+
+      </para>
+
+      <sconstruct>
+        Import('env', 'debug')
+        env = env.Clone(DEBUG = debug)
+        env.Program('prog', ['prog.c'])
+      </sconstruct>
+
+      <para>
+
+      And the &Import; function will similarly
+      split a string along white-space
+      into separate variable names:
+
+      </para>
+
+      <sconstruct>
+        Import('env debug')
+        env = env.Clone(DEBUG = debug)
+        env.Program('prog', ['prog.c'])
+      </sconstruct>
+
+      <para>
+
+      Lastly, as a special case,
+      you may import all of the variables that
+      have been exported by supplying an asterisk
+      to the &Import; function:
+
+      </para>
+
+      <sconstruct>
+        Import('*')
+        env = env.Clone(DEBUG = debug)
+        env.Program('prog', ['prog.c'])
+      </sconstruct>
+
+      <para>
+
+      If you're dealing with a lot of &SConscript; files,
+      this can be a lot simpler than keeping
+      arbitrary lists of imported variables in each file.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Returning Values From an &SConscript; File</title>
+
+      <para>
+
+      Sometimes, you would like to be able to
+      use information from a subsidiary
+      &SConscript file in some way.
+      For example,
+      suppose that you want to create one
+      library from source files
+      scattered throughout a number
+      of subsidiary &SConscript; files.
+      You can do this by using the &Return;
+      function to return values
+      from the subsidiary &SConscript; files
+      to the calling file.
+
+      </para>
+
+      <para>
+
+      If, for example, we have two subdirectories
+      &foo; and &bar;
+      that should each contribute a source
+      file to a Library,
+      what we'd like to be able to do is
+      collect the object files
+      from the subsidiary &SConscript; calls
+      like this:
+
+      </para>
+
+      <scons_example name="Return">
+        <file name="SConstruct" printme="1">
+          env = Environment()
+          Export('env')
+          objs = []
+          for subdir in ['foo', 'bar']:
+              o = SConscript('%s/SConscript' % subdir)
+              objs.append(o)
+          env.Library('prog', objs)
+        </file>
+        <directory name="foo"></directory>
+        <directory name="bar"></directory>
+        <file name="foo/SConscript">
+          Import('env')
+          obj = env.Object('foo.c')
+          Return('obj')
+        </file>
+        <file name="bar/SConscript">
+          Import('env')
+          obj = env.Object('bar.c')
+          Return('obj')
+        </file>
+        <file name="foo/foo.c">
+          void foo(void) { printf("foo/foo.c\n"); }
+        </file>
+        <file name="bar/bar.c">
+          void bar(void) { printf("bar/bar.c\n"); }
+        </file>
+      </scons_example>
+
+      <para>
+
+      We can do this by using the &Return;
+      function in the
+      <literal>foo/SConscript</literal> file like this:
+
+      </para>
+
+      <scons_example_file example="Return" name="foo/SConscript">
+      </scons_example_file>
+
+      <para>
+
+      (The corresponding
+      <literal>bar/SConscript</literal>
+      file should be pretty obvious.)
+      Then when we run &SCons;,
+      the object files from the subsidiary subdirectories
+      are all correctly archived in the desired library:
+
+      </para>
+
+      <scons_output example="Return">
+        <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <!--
+      XXX Return(stop=False)
+      -->
+
+    </section>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Executing From a Subdirectory:  the -D, -u and -U Options</title>
+
+    <para>
+
+    XXX -D, -u and -U
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/hierarchy.xml b/doc/user/hierarchy.xml
new file mode 100644
index 0000000..3495c5f
--- /dev/null
+++ b/doc/user/hierarchy.xml
@@ -0,0 +1,746 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+
+=head2 The Build command
+
+By default, Cons does not change its working directory to the directory
+containing a subsidiary F<Conscript> file it is including.  This behavior
+can be enabled for a build by specifying, in the top-level F<Construct>
+file:
+
+  Conscript_chdir 1;
+
+When enabled, Cons will change to the subsidiary F<Conscript> file's
+containing directory while reading in that file, and then change back
+to the top-level directory once the file has been processed.
+
+It is expected that this behavior will become the default in some future
+version of Cons.  To prepare for this transition, builds that expect
+Cons to remain at the top of the build while it reads in a subsidiary
+F<Conscript> file should explicitly disable this feature as follows:
+
+  Conscript_chdir 0;
+
+=head2 Relative, top-relative, and absolute file names
+
+(There is another file prefix, ``!'', that is interpreted specially by
+Cons.  See discussion of the C<Link> command, below, for details.)
+
+
+=head2 Using modules in build scripts
+
+You may pull modules into each F<Conscript> file using the normal Perl
+C<use> or C<require> statements:
+
+  use English;
+  require My::Module;
+
+Each C<use> or C<require> only affects the one F<Conscript> file in which
+it appears.  To use a module in multiple F<Conscript> files, you must
+put a C<use> or C<require> statement in each one that needs the module.
+
+
+=head2 Scope of variables
+
+The top-level F<Construct> file and all F<Conscript> files begin life in
+a common, separate Perl package.  B<Cons> controls the symbol table for
+the package so that, the symbol table for each script is empty, except
+for the F<Construct> file, which gets some of the command line arguments.
+All of the variables that are set or used, therefore, are set by the
+script itself, not by some external script.
+
+Variables can be explicitly B<imported> by a script from its parent
+script. To import a variable, it must have been B<exported> by the parent
+and initialized (otherwise an error will occur).
+
+
+=head2 The Export command
+
+The C<Export> command is used as in the following example:
+
+  $env = new cons();
+  $INCLUDE = "#export/include";
+  $LIB = "#export/lib";
+  Export qw( env INCLUDE LIB );
+  Build qw( util/Conscript );
+
+The values of the simple variables mentioned in the C<Export> list will be
+squirreled away by any subsequent C<Build> commands. The C<Export> command
+will only export Perl B<scalar> variables, that is, variables whose name
+begins with C<$>. Other variables, objects, etc. can be exported by
+reference, but all scripts will refer to the same object, and this object
+should be considered to be read-only by the subsidiary scripts and by the
+original exporting script. It's acceptable, however, to assign a new value
+to the exported scalar variable, that won't change the underlying variable
+referenced. This sequence, for example, is OK:
+
+  $env = new cons();
+  Export qw( env INCLUDE LIB );
+  Build qw( util/Conscript );
+  $env = new cons(CFLAGS => '-O');
+  Build qw( other/Conscript );
+
+It doesn't matter whether the variable is set before or after the C<Export>
+command. The important thing is the value of the variable at the time the
+C<Build> command is executed. This is what gets squirreled away. Any
+subsequent C<Export> commands, by the way, invalidate the first: you must
+mention all the variables you wish to export on each C<Export> command.
+
+
+=head2 The Import command
+
+Variables exported by the C<Export> command can be imported into subsidiary
+scripts by the C<Import> command. The subsidiary script always imports
+variables directly from the superior script. Consider this example:
+
+  Import qw( env INCLUDE );
+
+This is only legal if the parent script exported both C<$env> and
+C<$INCLUDE>. It also must have given each of these variables values. It is
+OK for the subsidiary script to only import a subset of the exported
+variables (in this example, C<$LIB>, which was exported by the previous
+example, is not imported).
+
+All the imported variables are automatically re-exported, so the sequence:
+
+  Import qw ( env INCLUDE );
+  Build qw ( beneath-me/Conscript );
+
+will supply both C<$env> and C<$INCLUDE> to the subsidiary file. If only
+C<$env> is to be exported, then the following will suffice:
+
+  Import qw ( env INCLUDE );
+  Export qw ( env );
+  Build qw ( beneath-me/Conscript );
+
+Needless to say, the variables may be modified locally before invoking
+C<Build> on the subsidiary script.
+
+=head2 Build script evaluation order
+
+The only constraint on the ordering of build scripts is that superior
+scripts are evaluated before their inferior scripts. The top-level
+F<Construct> file, for instance, is evaluated first, followed by any
+inferior scripts. This is all you really need to know about the evaluation
+order, since order is generally irrelevant. Consider the following C<Build>
+command:
+
+  Build qw(
+	drivers/display/Conscript
+	drivers/mouse/Conscript
+	parser/Conscript
+	utilities/Conscript
+  );
+
+We've chosen to put the script names in alphabetical order, simply because
+that's the most convenient for maintenance purposes. Changing the order will
+make no difference to the build.
+
+-->
+
+  <para>
+
+  The source code for large software projects
+  rarely stays in a single directory,
+  but is nearly always divided into a
+  hierarchy of directories.
+  Organizing a large software build using &SCons;
+  involves creating a hierarchy of build scripts
+  using the &SConscript; function.
+
+  </para>
+
+  <section>
+  <title>&SConscript; Files</title>
+
+    <para>
+
+    As we've already seen,
+    the build script at the top of the tree is called &SConstruct;.
+    The top-level &SConstruct; file can
+    use the &SConscript; function to
+    include other subsidiary scripts in the build.
+    These subsidiary scripts can, in turn,
+    use the &SConscript; function
+    to include still other scripts in the build.
+    By convention, these subsidiary scripts are usually
+    named &SConscript;.
+    For example, a top-level &SConstruct; file might
+    arrange for four subsidiary scripts to be included
+    in the build as follows:
+
+    </para>
+
+    <programlisting>
+      SConscript(['drivers/display/SConscript',
+                  'drivers/mouse/SConscript',
+                  'parser/SConscript',
+                  'utilities/SConscript'])
+    </programlisting>
+
+    <para>
+
+    In this case, the &SConstruct; file
+    lists all of the &SConscript; files in the build explicitly.
+    (Note, however, that not every directory in the tree
+    necessarily has an &SConscript; file.)
+    Alternatively, the <literal>drivers</literal>
+    subdirectory might contain an intermediate
+    &SConscript; file,
+    in which case the &SConscript; call in
+    the top-level &SConstruct; file
+    would look like:
+
+    </para>
+
+    <programlisting>
+      SConscript(['drivers/SConscript',
+                  'parser/SConscript',
+                  'utilities/SConscript'])
+    </programlisting>
+
+    <para>
+
+    And the subsidiary &SConscript; file in the
+    <literal>drivers</literal> subdirectory
+    would look like:
+
+    </para>
+
+    <programlisting>
+      SConscript(['display/SConscript',
+                  'mouse/SConscript'])
+    </programlisting>
+
+    <para>
+
+    Whether you list all of the &SConscript; files in the
+    top-level &SConstruct; file,
+    or place a subsidiary &SConscript; file in
+    intervening directories,
+    or use some mix of the two schemes,
+    is up to you and the needs of your software.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Path Names Are Relative to the &SConscript; Directory</title>
+
+    <para>
+
+    Subsidiary &SConscript; files make it easy to create a build
+    hierarchy because all of the file and directory names
+    in a subsidiary &SConscript; files are interpreted
+    relative to the directory in which the &SConscript; file lives.
+    Typically, this allows the &SConscript; file containing the
+    instructions to build a target file
+    to live in the same directory as the source files
+    from which the target will be built,
+    making it easy to update how the software is built
+    whenever files are added or deleted
+    (or other changes are made).
+
+    </para>
+
+    <para>
+
+    For example, suppose we want to build two programs
+    &prog1; and &prog2; in two separate directories
+    with the same names as the programs.
+    One typical way to do this would be
+    with a top-level &SConstruct; file like this:
+
+    </para>
+
+    <programlisting>
+      SConscript(['prog1/SConscript',
+                  'prog2/SConscript'])
+    </programlisting>
+
+    <para>
+
+    And subsidiary &SConscript; files that look like this:
+
+    </para>
+
+    
+    <programlisting>
+      env = Environment()
+      env.Program('prog1', ['main.c', 'foo1.c', 'foo2.c'])
+      </programlisting>
+
+    <para>
+
+    And this:
+
+    </para>
+
+    
+    <programlisting>
+      env = Environment()
+      env.Program('prog2', ['main.c', 'bar1.c', 'bar2.c'])
+      </programlisting>
+
+    <para>
+
+    Then, when we run &SCons; in the top-level directory,
+    our build looks like:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       cc -o prog1/foo1.o -c prog1/foo1.c
+       cc -o prog1/foo2.o -c prog1/foo2.c
+       cc -o prog1/main.o -c prog1/main.c
+       cc -o prog1/prog1 prog1/main.o prog1/foo1.o prog1/foo2.o
+       cc -o prog2/bar1.o -c prog2/bar1.c
+       cc -o prog2/bar2.o -c prog2/bar2.c
+       cc -o prog2/main.o -c prog2/main.c
+       cc -o prog2/prog2 prog2/main.o prog2/bar1.o prog2/bar2.o
+    </screen>
+
+    <para>
+
+    Notice the following:
+
+    First, you can have files with the same names
+    in multiple directories, like main.c in the above example.
+
+    Second, unlike standard recursive use of &Make;,
+    &SCons; stays in the top-level directory
+    (where the &SConstruct; file lives)
+    and issues commands that use the path names
+    from the top-level directory to the
+    target and source files within the hierarchy.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Top-Level Path Names in Subsidiary &SConscript; Files</title>
+
+    <para>
+
+    If you need to use a file from another directory,
+    it's sometimes more convenient to specify
+    the path to a file in another directory
+    from the top-level &SConstruct; directory,
+    even when you're using that file in
+    a subsidiary &SConscript; file in a subdirectory.
+    You can tell &SCons; to interpret a path name
+    as relative to the top-level &SConstruct; directory,
+    not the local directory of the &SConscript; file,
+    by appending a &hash; (hash mark)
+    to the beginning of the path name:
+
+    </para>
+
+    <programlisting>
+       env = Environment()
+       env.Program('prog', ['main.c', '#lib/foo1.c', 'foo2.c'])
+    </programlisting>
+
+    <para>
+
+    In this example,
+    the <literal>lib</literal> directory is
+    directly underneath the top-level &SConstruct; directory.
+    If the above &SConscript; file is in a subdirectory
+    named <literal>src/prog</literal>,
+    the output would look like:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       cc -o lib/foo1.o -c lib/foo1.c
+       cc -o src/prog/foo2.o -c src/prog/foo2.c
+       cc -o src/prog/main.o -c src/prog/main.c
+       cc -o src/prog/prog src/prog/main.o lib/foo1.o src/prog/foo2.o
+    </screen>
+
+    <para>
+
+    (Notice that the <literal>lib/foo1.o</literal> object file
+    is built in the same directory as its source file.
+    See <xref linkend="chap-separate"></xref>, below,
+    for information about
+    how to build the object file in a different subdirectory.)
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Absolute Path Names</title>
+
+    <para>
+
+    Of course, you can always specify
+    an absolute path name for a file--for example:
+
+    </para>
+
+    <programlisting>
+       env = Environment()
+       env.Program('prog', ['main.c', '/usr/joe/lib/foo1.c', 'foo2.c'])
+    </programlisting>
+
+    <para>
+
+    Which, when executed, would yield:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       cc -o src/prog/foo2.o -c src/prog/foo2.c
+       cc -o src/prog/main.o -c src/prog/main.c
+       cc -o /usr/joe/lib/foo1.o -c /usr/joe/lib/foo1.c
+       cc -o src/prog/prog src/prog/main.o /usr/joe/lib/foo1.o src/prog/foo2.o
+    </screen>
+
+    <para>
+
+    (As was the case with top-relative path names,
+    notice that the <literal>/usr/joe/lib/foo1.o</literal> object file
+    is built in the same directory as its source file.
+    See <xref linkend="chap-separate"></xref>, below,
+    for information about
+    how to build the object file in a different subdirectory.)
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Sharing Environments (and Other Variables) Between &SConscript; Files</title>
+
+    <para>
+
+    In the previous example,
+    each of the subsidiary &SConscript; files
+    created its own construction environment
+    by calling &Environment; separately.
+    This obviously works fine,
+    but if each program must be built
+    with the same construction variables,
+    it's cumbersome and error-prone to initialize
+    separate construction environments
+    in the same way over and over in each subsidiary
+    &SConscript; file.
+
+    </para>
+
+    <para>
+
+    &SCons; supports the ability to <emphasis>export</emphasis> variables
+    from a parent &SConscript; file
+    to its subsidiary &SConscript; files,
+    which allows you to share common initialized
+    values throughout your build hierarchy.
+
+    </para>
+
+    <section>
+    <title>Exporting Variables</title>
+
+      <para>
+
+      There are two ways to export a variable,
+      such as a construction environment,
+      from an &SConscript; file,
+      so that it may be used by other &SConscript; files.
+      First, you can call the &Export;
+      function with a list of variables,
+      or a string of white-space separated variable names.
+      Each call to &Export; adds one
+      or more variables to a global list
+      of variables that are available for import
+      by other &SConscript; files.
+
+      </para>
+
+      <programlisting>
+        env = Environment()
+        Export('env')
+      </programlisting>
+
+      <para>
+
+      You may export more than one variable name at a time:
+
+      </para>
+
+      <programlisting>
+        env = Environment()
+        debug = ARGUMENTS['debug']
+        Export('env', 'debug')
+      </programlisting>
+
+      <para>
+
+      Because white space is not legal in Python variable names,
+      the &Export; function will even automatically split
+      a string into separate names for you:
+
+      </para>
+
+      <programlisting>
+        Export('env debug')
+      </programlisting>
+
+      <para>
+
+      Second, you can specify a list of
+      variables to export as a second argument
+      to the &SConscript; function call:
+
+      </para>
+
+      <programlisting>
+        SConscript('src/SConscript', 'env')
+      </programlisting>
+
+      <para>
+
+      Or as the &exports; keyword argument:
+
+      </para>
+
+      <programlisting>
+        SConscript('src/SConscript', exports='env')
+      </programlisting>
+
+      <para>
+
+      These calls export the specified variables
+      to only the listed &SConscript; files.
+      You may, however, specify more than one
+      &SConscript; file in a list:
+
+      </para>
+
+      <programlisting>
+        SConscript(['src1/SConscript',
+                    'src2/SConscript'], exports='env')
+      </programlisting>
+
+      <para>
+
+      This is functionally equivalent to
+      calling the &SConscript; function
+      multiple times with the same &exports; argument,
+      one per &SConscript; file.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Importing Variables</title>
+
+      <para>
+
+      Once a variable has been exported from a calling
+      &SConscript; file,
+      it may be used in other &SConscript; files
+      by calling the &Import; function:
+
+      </para>
+
+      <programlisting>
+        Import('env')
+        env.Program('prog', ['prog.c'])
+      </programlisting>
+
+      <para>
+
+      The &Import; call makes the <literal>env</literal> construction
+      environment available to the &SConscript; file,
+      after which the variable can be used to build
+      programs, libraries, etc.
+
+      </para>
+
+      <para>
+
+      Like the &Export; function,
+      the &Import; function can be used
+      with multiple variable names:
+
+      </para>
+
+      <programlisting>
+        Import('env', 'debug')
+        env = env.Clone(DEBUG = debug)
+        env.Program('prog', ['prog.c'])
+      </programlisting>
+
+      <para>
+
+      And the &Import; function will similarly
+      split a string along white-space
+      into separate variable names:
+
+      </para>
+
+      <programlisting>
+        Import('env debug')
+        env = env.Clone(DEBUG = debug)
+        env.Program('prog', ['prog.c'])
+      </programlisting>
+
+      <para>
+
+      Lastly, as a special case,
+      you may import all of the variables that
+      have been exported by supplying an asterisk
+      to the &Import; function:
+
+      </para>
+
+      <programlisting>
+        Import('*')
+        env = env.Clone(DEBUG = debug)
+        env.Program('prog', ['prog.c'])
+      </programlisting>
+
+      <para>
+
+      If you're dealing with a lot of &SConscript; files,
+      this can be a lot simpler than keeping
+      arbitrary lists of imported variables in each file.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Returning Values From an &SConscript; File</title>
+
+      <para>
+
+      Sometimes, you would like to be able to
+      use information from a subsidiary
+      &SConscript; file in some way.
+      For example,
+      suppose that you want to create one
+      library from source files
+      scattered throughout a number
+      of subsidiary &SConscript; files.
+      You can do this by using the &Return;
+      function to return values
+      from the subsidiary &SConscript; files
+      to the calling file.
+
+      </para>
+
+      <para>
+
+      If, for example, we have two subdirectories
+      &foo; and &bar;
+      that should each contribute a source
+      file to a Library,
+      what we'd like to be able to do is
+      collect the object files
+      from the subsidiary &SConscript; calls
+      like this:
+
+      </para>
+
+      <programlisting>
+          env = Environment()
+          Export('env')
+          objs = []
+          for subdir in ['foo', 'bar']:
+              o = SConscript('%s/SConscript' % subdir)
+              objs.append(o)
+          env.Library('prog', objs)
+      </programlisting>
+
+      <para>
+
+      We can do this by using the &Return;
+      function in the
+      <literal>foo/SConscript</literal> file like this:
+
+      </para>
+
+      
+      <programlisting>
+          Import('env')
+          obj = env.Object('foo.c')
+          Return('obj')
+        </programlisting>
+
+      <para>
+
+      (The corresponding
+      <literal>bar/SConscript</literal>
+      file should be pretty obvious.)
+      Then when we run &SCons;,
+      the object files from the subsidiary subdirectories
+      are all correctly archived in the desired library:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q</userinput>
+        cc -o bar/bar.o -c bar/bar.c
+        cc -o foo/foo.o -c foo/foo.c
+        ar rc libprog.a foo/foo.o bar/bar.o
+        ranlib libprog.a
+      </screen>
+
+      <!--
+      XXX Return(stop=False)
+      -->
+
+    </section>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Executing From a Subdirectory:  the -D, -u and -U Options</title>
+
+    <para>
+
+    XXX -D, -u and -U
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/install.in b/doc/user/install.in
new file mode 100644
index 0000000..cce2de3
--- /dev/null
+++ b/doc/user/install.in
@@ -0,0 +1,247 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  Once a program is built,
+  it is often appropriate to install it in another
+  directory for public use.
+  You use the &Install; method 
+  to arrange for a program, or any other file,
+  to be copied into a destination directory:
+
+  </para>
+
+  <scons_example name="ex1">
+     <file name="SConstruct" printme="1">
+     env = Environment()
+     hello = env.Program('hello.c')
+     env.Install('__ROOT__/usr/bin', hello)
+     </file>
+     <file name="hello.c">
+     int main() { printf("Hello, world!\n"); }
+     </file>
+  </scons_example>
+
+  <para>
+
+  Note, however, that installing a file is
+  still considered a type of file "build."
+  This is important when you remember that
+  the default behavior of &SCons; is
+  to build files in or below the current directory.
+  If, as in the example above,
+  you are installing files in a directory
+  outside of the top-level &SConstruct; file's directory tree,
+  you must specify that directory
+  (or a higher directory, such as <literal>/</literal>)
+  for it to install anything there:
+
+  </para>
+
+  <scons_output example="ex1">
+     <scons_output_command>scons -Q</scons_output_command>
+     <scons_output_command>scons -Q __ROOT__/usr/bin</scons_output_command>
+  </scons_output>
+
+  <para>
+
+  It can, however, be cumbersome to remember
+  (and type) the specific destination directory
+  in which the program (or any other file)
+  should be installed.
+  This is an area where the &Alias;
+  function comes in handy,
+  allowing you, for example,
+  to create a pseudo-target named <literal>install</literal>
+  that can expand to the specified destination directory:
+
+  </para>
+
+  <scons_example name="ex2">
+    <file name="SConstruct" printme="1">
+     env = Environment()
+     hello = env.Program('hello.c')
+     env.Install('__ROOT__/usr/bin', hello)
+     env.Alias('install', '__ROOT__/usr/bin')
+    </file>
+    <file name="hello.c">
+    int main() { printf("Hello, world!\n"); }
+    </file>
+  </scons_example>
+
+  <para>
+
+  This then yields the more natural
+  ability to install the program
+  in its destination as follows:
+
+  </para>
+
+  <scons_output example="ex2">
+     <scons_output_command>scons -Q</scons_output_command>
+     <scons_output_command>scons -Q install</scons_output_command>
+  </scons_output>
+
+  <section>
+  <title>Installing Multiple Files in a Directory</title>
+
+    <para>
+
+    You can install multiple files into a directory
+    simply by calling the &Install; function multiple times:
+
+    </para>
+
+    <scons_example name="ex3">
+      <file name="SConstruct" printme="1">
+       env = Environment()
+       hello = env.Program('hello.c')
+       goodbye = env.Program('goodbye.c')
+       env.Install('__ROOT__/usr/bin', hello)
+       env.Install('__ROOT__/usr/bin', goodbye)
+       env.Alias('install', '__ROOT__/usr/bin')
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+      <file name="goodbye.c">
+      int main() { printf("Goodbye, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Or, more succinctly, listing the multiple input
+    files in a list
+    (just like you can do with any other builder):
+
+    </para>
+
+    <sconstruct>
+       env = Environment()
+       hello = env.Program('hello.c')
+       goodbye = env.Program('goodbye.c')
+       env.Install('__ROOT__/usr/bin', [hello, goodbye])
+       env.Alias('install', '__ROOT__/usr/bin')
+    </sconstruct>
+
+    <para>
+
+    Either of these two examples yields:
+
+    </para>
+
+    <scons_output example="ex3">
+       <scons_output_command>scons -Q install</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Installing a File Under a Different Name</title>
+
+    <para>
+
+    The &Install; method preserves the name
+    of the file when it is copied into the
+    destination directory.
+    If you need to change the name of the file
+    when you copy it, use the &InstallAs; function:
+
+    </para>
+
+    <scons_example name="ex4">
+      <file name="SConstruct" printme="1">
+       env = Environment()
+       hello = env.Program('hello.c')
+       env.InstallAs('__ROOT__/usr/bin/hello-new', hello)
+       env.Alias('install', '__ROOT__/usr/bin')
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    This installs the <literal>hello</literal>
+    program with the name <literal>hello-new</literal>
+    as follows:
+
+    </para>
+
+    <scons_output example="ex4">
+       <scons_output_command>scons -Q install</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Installing Multiple Files Under Different Names</title>
+
+    <para>
+
+    Lastly, if you have multiple files that all
+    need to be installed with different file names,
+    you can either call the &InstallAs; function
+    multiple times, or as a shorthand,
+    you can supply same-length lists
+    for both the target and source arguments:
+
+    </para>
+
+    <scons_example name="ex5">
+      <file name="SConstruct" printme="1">
+       env = Environment()
+       hello = env.Program('hello.c')
+       goodbye = env.Program('goodbye.c')
+       env.InstallAs(['__ROOT__/usr/bin/hello-new',
+                      '__ROOT__/usr/bin/goodbye-new'],
+                     [hello, goodbye])
+       env.Alias('install', '__ROOT__/usr/bin')
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+      <file name="goodbye.c">
+      int main() { printf("Goodbye, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    In this case, the &InstallAs; function
+    loops through both lists simultaneously,
+    and copies each source file into its corresponding
+    target file name:
+
+    </para>
+
+    <scons_output example="ex5">
+       <scons_output_command>scons -Q install</scons_output_command>
+    </scons_output>
+
+  </section>
diff --git a/doc/user/install.xml b/doc/user/install.xml
new file mode 100644
index 0000000..e011986
--- /dev/null
+++ b/doc/user/install.xml
@@ -0,0 +1,237 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  Once a program is built,
+  it is often appropriate to install it in another
+  directory for public use.
+  You use the &Install; method 
+  to arrange for a program, or any other file,
+  to be copied into a destination directory:
+
+  </para>
+
+  <programlisting>
+     env = Environment()
+     hello = env.Program('hello.c')
+     env.Install('/usr/bin', hello)
+  </programlisting>
+
+  <para>
+
+  Note, however, that installing a file is
+  still considered a type of file "build."
+  This is important when you remember that
+  the default behavior of &SCons; is
+  to build files in or below the current directory.
+  If, as in the example above,
+  you are installing files in a directory
+  outside of the top-level &SConstruct; file's directory tree,
+  you must specify that directory
+  (or a higher directory, such as <literal>/</literal>)
+  for it to install anything there:
+
+  </para>
+
+  <screen>
+     % <userinput>scons -Q</userinput>
+     cc -o hello.o -c hello.c
+     cc -o hello hello.o
+     % <userinput>scons -Q /usr/bin</userinput>
+     Install file: "hello" as "/usr/bin/hello"
+  </screen>
+
+  <para>
+
+  It can, however, be cumbersome to remember
+  (and type) the specific destination directory
+  in which the program (or any other file)
+  should be installed.
+  This is an area where the &Alias;
+  function comes in handy,
+  allowing you, for example,
+  to create a pseudo-target named <literal>install</literal>
+  that can expand to the specified destination directory:
+
+  </para>
+
+  <programlisting>
+     env = Environment()
+     hello = env.Program('hello.c')
+     env.Install('/usr/bin', hello)
+     env.Alias('install', '/usr/bin')
+  </programlisting>
+
+  <para>
+
+  This then yields the more natural
+  ability to install the program
+  in its destination as follows:
+
+  </para>
+
+  <screen>
+     % <userinput>scons -Q</userinput>
+     cc -o hello.o -c hello.c
+     cc -o hello hello.o
+     % <userinput>scons -Q install</userinput>
+     Install file: "hello" as "/usr/bin/hello"
+  </screen>
+
+  <section>
+  <title>Installing Multiple Files in a Directory</title>
+
+    <para>
+
+    You can install multiple files into a directory
+    simply by calling the &Install; function multiple times:
+
+    </para>
+
+    <programlisting>
+       env = Environment()
+       hello = env.Program('hello.c')
+       goodbye = env.Program('goodbye.c')
+       env.Install('/usr/bin', hello)
+       env.Install('/usr/bin', goodbye)
+       env.Alias('install', '/usr/bin')
+    </programlisting>
+
+    <para>
+
+    Or, more succinctly, listing the multiple input
+    files in a list
+    (just like you can do with any other builder):
+
+    </para>
+
+    <programlisting>
+       env = Environment()
+       hello = env.Program('hello.c')
+       goodbye = env.Program('goodbye.c')
+       env.Install('/usr/bin', [hello, goodbye])
+       env.Alias('install', '/usr/bin')
+    </programlisting>
+
+    <para>
+
+    Either of these two examples yields:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q install</userinput>
+       cc -o goodbye.o -c goodbye.c
+       cc -o goodbye goodbye.o
+       Install file: "goodbye" as "/usr/bin/goodbye"
+       cc -o hello.o -c hello.c
+       cc -o hello hello.o
+       Install file: "hello" as "/usr/bin/hello"
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Installing a File Under a Different Name</title>
+
+    <para>
+
+    The &Install; method preserves the name
+    of the file when it is copied into the
+    destination directory.
+    If you need to change the name of the file
+    when you copy it, use the &InstallAs; function:
+
+    </para>
+
+    <programlisting>
+       env = Environment()
+       hello = env.Program('hello.c')
+       env.InstallAs('/usr/bin/hello-new', hello)
+       env.Alias('install', '/usr/bin')
+    </programlisting>
+
+    <para>
+
+    This installs the <literal>hello</literal>
+    program with the name <literal>hello-new</literal>
+    as follows:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q install</userinput>
+       cc -o hello.o -c hello.c
+       cc -o hello hello.o
+       Install file: "hello" as "/usr/bin/hello-new"
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Installing Multiple Files Under Different Names</title>
+
+    <para>
+
+    Lastly, if you have multiple files that all
+    need to be installed with different file names,
+    you can either call the &InstallAs; function
+    multiple times, or as a shorthand,
+    you can supply same-length lists
+    for both the target and source arguments:
+
+    </para>
+
+    <programlisting>
+       env = Environment()
+       hello = env.Program('hello.c')
+       goodbye = env.Program('goodbye.c')
+       env.InstallAs(['/usr/bin/hello-new',
+                      '/usr/bin/goodbye-new'],
+                     [hello, goodbye])
+       env.Alias('install', '/usr/bin')
+    </programlisting>
+
+    <para>
+
+    In this case, the &InstallAs; function
+    loops through both lists simultaneously,
+    and copies each source file into its corresponding
+    target file name:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q install</userinput>
+       cc -o goodbye.o -c goodbye.c
+       cc -o goodbye goodbye.o
+       Install file: "goodbye" as "/usr/bin/goodbye-new"
+       cc -o hello.o -c hello.c
+       cc -o hello hello.o
+       Install file: "hello" as "/usr/bin/hello-new"
+    </screen>
+
+  </section>
diff --git a/doc/user/java.in b/doc/user/java.in
new file mode 100644
index 0000000..358d79b
--- /dev/null
+++ b/doc/user/java.in
@@ -0,0 +1,657 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  So far, we've been using examples of
+  building C and C++ programs
+  to demonstrate the features of &SCons;.
+  &SCons; also supports building Java programs,
+  but Java builds are handled slightly differently,
+  which reflects the ways in which
+  the Java compiler and tools
+  build programs differently than
+  other languages' tool chains.
+
+  </para>
+
+  <section>
+  <title>Building Java Class Files:  the &b-Java; Builder</title>
+
+    <para>
+
+    The basic activity when programming in Java,
+    of course, is to take one or more <filename>.java</filename> files
+    containing Java source code
+    and to call the Java compiler
+    to turn them into one or more
+    <filename>.class</filename> files.
+    In &SCons;, you do this
+    by giving the &b-link-Java; Builder
+    a target directory in which
+    to put the <filename>.class</filename> files,
+    and a source directory that contains
+    the <filename>.java</filename> files:
+
+    </para>
+
+    <scons_example name="java">
+      <file name="SConstruct" printme="1">
+      Java('classes', 'src')
+      </file>
+      <file name="src/Example1.java">
+      public class Example1
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      </file>
+      <file name="src/Example2.java">
+      public class Example2
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      </file>
+      <file name="src/Example3.java">
+      public class Example3
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      </file>
+    </scons_example>
+
+    <para>
+
+    If the <filename>src</filename> directory contains
+    three <filename>.java</filename> source files,
+    then running &SCons; might look like this:
+
+    </para>
+
+    <scons_output example="java">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    &SCons; will actually search the <filename>src</filename>
+    directory tree for all of the <filename>.java</filename> files.
+    The Java compiler will then create the
+    necessary class files in the <filename>classes</filename> subdirectory,
+    based on the class names found in the <filename>.java</filename> files.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>How &SCons; Handles Java Dependencies</title>
+
+    <para>
+
+    In addition to searching the source directory for
+    <filename>.java</filename> files,
+    &SCons; actually runs the <filename>.java</filename> files
+    through a stripped-down Java parser that figures out
+    what classes are defined.
+    In other words, &SCons; knows,
+    without you having to tell it,
+    what <filename>.class</filename> files
+    will be produced by the &javac; call.
+    So our one-liner example from the preceding section:
+
+    </para>
+
+    <scons_example name="java-classes">
+      <file name="SConstruct" printme="1">
+      Java('classes', 'src')
+      </file>
+      <file name="src/Example1.java">
+      public class Example1
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      public class AdditionalClass1
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      </file>
+      <file name="src/Example2.java">
+      public class Example2
+      {
+        class Inner2 {
+          public static void main(String[] args)
+          {
+            System.out.println("Hello Java world!\n");
+          }
+        }
+      }
+      </file>
+      <file name="src/Example3.java">
+      public class Example3
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      public class AdditionalClass3
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Will not only tell you reliably
+    that the <filename>.class</filename> files
+    in the <filename>classes</filename> subdirectory 
+    are up-to-date:
+
+    </para>
+
+    <scons_output example="java-classes">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q classes</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    But it will also remove all of the generated
+    <filename>.class</filename> files,
+    even for inner classes,
+    without you having to specify them manually.
+    For example, if our
+    <filename>Example1.java</filename>
+    and
+    <filename>Example3.java</filename>
+    files both define additional classes,
+    and the class defined in <filename>Example2.java</filename>
+    has an inner class,
+    running <userinput>scons -c</userinput>
+    will clean up all of those <filename>.class</filename> files
+    as well:
+
+    </para>
+
+    <scons_output example="java-classes">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q -c classes</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    To ensure correct handling of <filename>.class</filename>
+    dependencies in all cases, you need to tell &SCons; which Java
+    version is being used.  This is needed because Java 1.5 changed
+    the <filename>.class</filename> file names for nested anonymous
+    inner classes.  Use the <varname>JAVAVERSION</varname> construction
+    variable to specify the version in use.  With Java 1.6, the
+    one-liner example can then be defined like this:
+
+    </para> 
+
+    <sconstruct>
+      Java('classes', 'src', JAVAVERSION='1.6')
+    </sconstruct>
+
+    <para>
+    See <varname>JAVAVERSION</varname> in the man page for more information.
+    </para>
+
+  </section>
+
+  <section>
+  <title>Building Java Archive (<filename>.jar</filename>) Files:  the &b-Jar; Builder</title>
+
+    <para>
+
+    After building the class files,
+    it's common to collect them into
+    a Java archive (<filename>.jar</filename>) file,
+    which you do by calling the &b-link-Jar; Builder method.
+    If you want to just collect all of the
+    class files within a subdirectory,
+    you can just specify that subdirectory
+    as the &b-Jar; source:
+
+    </para>
+
+    <scons_example name="jar1">
+      <file name="SConstruct" printme="1">
+      Java(target = 'classes', source = 'src')
+      Jar(target = 'test.jar', source = 'classes')
+      </file>
+      <file name="src/Example1.java">
+      public class Example1
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      </file>
+      <file name="src/Example2.java">
+      public class Example2
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      </file>
+      <file name="src/Example3.java">
+      public class Example3
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      </file>
+    </scons_example>
+
+    <para>
+
+    &SCons; will then pass that directory
+    to the &jar; command,
+    which will collect all of the underlying
+    <filename>.class</filename> files:
+
+    </para>
+
+    <scons_output example="jar1">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    If you want to keep all of the
+    <filename>.class</filename> files
+    for multiple programs in one location,
+    and only archive some of them in
+    each <filename>.jar</filename> file,
+    you can pass the &b-Jar; builder a
+    list of files as its source.
+    It's extremely simple to create multiple
+    <filename>.jar</filename> files this way,
+    using the lists of target class files created
+    by calls to the &b-link-Java; builder
+    as sources to the various &b-Jar; calls:
+
+    </para>
+
+    <scons_example name="jar2">
+      <file name="SConstruct" printme="1">
+      prog1_class_files = Java(target = 'classes', source = 'prog1')
+      prog2_class_files = Java(target = 'classes', source = 'prog2')
+      Jar(target = 'prog1.jar', source = prog1_class_files)
+      Jar(target = 'prog2.jar', source = prog2_class_files)
+      </file>
+      <file name="prog1/Example1.java">
+      public class Example1
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      </file>
+      <file name="prog1/Example2.java">
+      public class Example2
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      </file>
+      <file name="prog2/Example3.java">
+      public class Example3
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      </file>
+      <file name="prog2/Example4.java">
+      public class Example4
+      {
+        public static void main(String[] args)
+        {
+          System.out.println("Hello Java world!\n");
+        }
+      }
+      </file>
+    </scons_example>
+
+    <para>
+
+    This will then create
+    <filename>prog1.jar</filename>
+    and <filename>prog2.jar</filename>
+    next to the subdirectories
+    that contain their <filename>.java</filename> files:
+
+    </para>
+
+    <scons_output example="jar2">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Building C Header and Stub Files:  the &b-JavaH; Builder</title>
+
+    <para>
+
+    You can generate C header and source files
+    for implementing native methods,
+    by using the &b-link-JavaH; Builder.
+    There are several ways of using the &JavaH Builder.
+    One typical invocation might look like:
+
+    </para>
+
+    <scons_example name="javah">
+      <file name="SConstruct" printme="1">
+      classes = Java(target = 'classes', source = 'src/pkg/sub')
+      JavaH(target = 'native', source = classes)
+      </file>
+      <file name="src/pkg/sub/Example1.java">
+      package pkg.sub;
+      public class Example1
+      {
+        public static void main(String[] args)
+        {
+        }
+      }
+      </file>
+      <file name="src/pkg/sub/Example2.java">
+      package pkg.sub;
+      public class Example2
+      {
+        public static void main(String[] args)
+        {
+        }
+      }
+      </file>
+      <file name="src/pkg/sub/Example3.java">
+      package pkg.sub;
+      public class Example3
+      {
+        public static void main(String[] args)
+        {
+        }
+      }
+      </file>
+    </scons_example>
+
+    <para>
+
+    The source is a list of class files generated by the
+    call to the &b-link-Java; Builder,
+    and the target is the output directory in
+    which we want the C header files placed.
+    The target
+    gets converted into the <option>-d</option>
+    when &SCons; runs &javah;:
+
+    </para>
+
+    <scons_output example="javah">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    In this case,
+    the call to &javah;
+    will generate the header files
+    <filename>native/pkg_sub_Example1.h</filename>,
+    <filename>native/pkg_sub_Example2.h</filename>
+    and
+    <filename>native/pkg_sub_Example3.h</filename>.
+    Notice that &SCons; remembered that the class
+    files were generated with a target directory of
+    <filename>classes</filename>,
+    and that it then specified that target directory
+    as the <option>-classpath</option> option
+    to the call to &javah;.
+
+    </para>
+
+    <para>
+
+    Although it's more convenient to use
+    the list of class files returned by
+    the &b-Java; Builder
+    as the source of a call to the &b-JavaH; Builder,
+    you <emphasis>can</emphasis>
+    specify the list of class files
+    by hand, if you prefer.
+    If you do,
+    you need to set the
+    &cv-link-JAVACLASSDIR; construction variable
+    when calling &b-JavaH;:
+
+    </para>
+
+    <scons_example name="JAVACLASSDIR">
+      <file name="SConstruct" printme="1">
+      Java(target = 'classes', source = 'src/pkg/sub')
+      class_file_list = ['classes/pkg/sub/Example1.class',
+                         'classes/pkg/sub/Example2.class',
+                         'classes/pkg/sub/Example3.class']
+      JavaH(target = 'native', source = class_file_list, JAVACLASSDIR = 'classes')
+      </file>
+      <file name="src/pkg/sub/Example1.java">
+      package pkg.sub;
+      public class Example1
+      {
+        public static void main(String[] args)
+        {
+        }
+      }
+      </file>
+      <file name="src/pkg/sub/Example2.java">
+      package pkg.sub;
+      public class Example2
+      {
+        public static void main(String[] args)
+        {
+        }
+      }
+      </file>
+      <file name="src/pkg/sub/Example3.java">
+      package pkg.sub;
+      public class Example3
+      {
+        public static void main(String[] args)
+        {
+        }
+      }
+      </file>
+    </scons_example>
+
+    <para>
+
+    The &cv-JAVACLASSDIR; value then
+    gets converted into the <option>-classpath</option>
+    when &SCons; runs &javah;:
+
+    </para>
+
+    <scons_output example="JAVACLASSDIR">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Lastly, if you don't want a separate header file
+    generated for each source file,
+    you can specify an explicit File Node
+    as the target of the &b-JavaH; Builder:
+
+    </para>
+
+    <scons_example name="javah_file">
+      <file name="SConstruct" printme="1">
+      classes = Java(target = 'classes', source = 'src/pkg/sub')
+      JavaH(target = File('native.h'), source = classes)
+      </file>
+      <file name="src/pkg/sub/Example1.java">
+      package pkg.sub;
+      public class Example1
+      {
+        public static void main(String[] args)
+        {
+        }
+      }
+      </file>
+      <file name="src/pkg/sub/Example2.java">
+      package pkg.sub;
+      public class Example2
+      {
+        public static void main(String[] args)
+        {
+        }
+      }
+      </file>
+      <file name="src/pkg/sub/Example3.java">
+      package pkg.sub;
+      public class Example3
+      {
+        public static void main(String[] args)
+        {
+        }
+      }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Because &SCons; assumes by default
+    that the target of the &b-JavaH; builder is a directory,
+    you need to use the &File; function
+    to make sure that &SCons; doesn't
+    create a directory named <filename>native.h</filename>.
+    When a file is used, though,
+    &SCons; correctly converts the file name
+    into the &javah; <option>-o</option> option:
+
+    </para>
+
+    <scons_output example="javah_file">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Building RMI Stub and Skeleton Class Files:  the &b-RMIC; Builder</title>
+
+    <para>
+
+    You can generate Remote Method Invocation stubs
+    by using the &b-link-RMIC; Builder.
+    The source is a list of directories,
+    typically returned by a call to the &b-link-Java; Builder,
+    and the target is an output directory
+    where the <filename>_Stub.class</filename>
+    and <filename>_Skel.class</filename> files will
+    be placed:
+
+    </para>
+
+    <scons_example name="RMIC">
+      <file name="SConstruct" printme="1">
+      classes = Java(target = 'classes', source = 'src/pkg/sub')
+      RMIC(target = 'outdir', source = classes)
+      </file>
+      <file name="src/pkg/sub/Example1.java">
+      package pkg.sub;
+      public class Example1
+      {
+        public static void main(String[] args)
+        {
+        }
+      }
+      </file>
+      <file name="src/pkg/sub/Example2.java">
+      package pkg.sub;
+      public class Example2
+      {
+        public static void main(String[] args)
+        {
+        }
+      }
+      </file>
+    </scons_example>
+
+    <para>
+
+    As it did with the &b-link-JavaH; Builder,
+    &SCons; remembers the class directory
+    and passes it as the <option>-classpath</option> option
+    to &rmic:
+
+    </para>
+
+    <scons_output example="RMIC">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    This example would generate the files
+    <filename>outdir/pkg/sub/Example1_Skel.class</filename>,
+    <filename>outdir/pkg/sub/Example1_Stub.class</filename>,
+    <filename>outdir/pkg/sub/Example2_Skel.class</filename> and
+    <filename>outdir/pkg/sub/Example2_Stub.class</filename>.
+
+    </para>
+
+  </section>
diff --git a/doc/user/java.xml b/doc/user/java.xml
new file mode 100644
index 0000000..8198b65
--- /dev/null
+++ b/doc/user/java.xml
@@ -0,0 +1,433 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  So far, we've been using examples of
+  building C and C++ programs
+  to demonstrate the features of &SCons;.
+  &SCons; also supports building Java programs,
+  but Java builds are handled slightly differently,
+  which reflects the ways in which
+  the Java compiler and tools
+  build programs differently than
+  other languages' tool chains.
+
+  </para>
+
+  <section>
+  <title>Building Java Class Files:  the &b-Java; Builder</title>
+
+    <para>
+
+    The basic activity when programming in Java,
+    of course, is to take one or more <filename>.java</filename> files
+    containing Java source code
+    and to call the Java compiler
+    to turn them into one or more
+    <filename>.class</filename> files.
+    In &SCons;, you do this
+    by giving the &b-link-Java; Builder
+    a target directory in which
+    to put the <filename>.class</filename> files,
+    and a source directory that contains
+    the <filename>.java</filename> files:
+
+    </para>
+
+    <programlisting>
+      Java('classes', 'src')
+    </programlisting>
+
+    <para>
+
+    If the <filename>src</filename> directory contains
+    three <filename>.java</filename> source files,
+    then running &SCons; might look like this:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      javac -d classes -sourcepath src src/Example1.java src/Example2.java src/Example3.java
+    </screen>
+
+    <para>
+
+    &SCons; will actually search the <filename>src</filename>
+    directory tree for all of the <filename>.java</filename> files.
+    The Java compiler will then create the
+    necessary class files in the <filename>classes</filename> subdirectory,
+    based on the class names found in the <filename>.java</filename> files.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>How &SCons; Handles Java Dependencies</title>
+
+    <para>
+
+    In addition to searching the source directory for
+    <filename>.java</filename> files,
+    &SCons; actually runs the <filename>.java</filename> files
+    through a stripped-down Java parser that figures out
+    what classes are defined.
+    In other words, &SCons; knows,
+    without you having to tell it,
+    what <filename>.class</filename> files
+    will be produced by the &javac; call.
+    So our one-liner example from the preceding section:
+
+    </para>
+
+    <programlisting>
+      Java('classes', 'src')
+    </programlisting>
+
+    <para>
+
+    Will not only tell you reliably
+    that the <filename>.class</filename> files
+    in the <filename>classes</filename> subdirectory 
+    are up-to-date:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      javac -d classes -sourcepath src src/Example1.java src/Example2.java src/Example3.java
+      % <userinput>scons -Q classes</userinput>
+      scons: `classes' is up to date.
+    </screen>
+
+    <para>
+
+    But it will also remove all of the generated
+    <filename>.class</filename> files,
+    even for inner classes,
+    without you having to specify them manually.
+    For example, if our
+    <filename>Example1.java</filename>
+    and
+    <filename>Example3.java</filename>
+    files both define additional classes,
+    and the class defined in <filename>Example2.java</filename>
+    has an inner class,
+    running <userinput>scons -c</userinput>
+    will clean up all of those <filename>.class</filename> files
+    as well:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      javac -d classes -sourcepath src src/Example1.java src/Example2.java src/Example3.java
+      % <userinput>scons -Q -c classes</userinput>
+      Removed classes/Example1.class
+      Removed classes/AdditionalClass1.class
+      Removed classes/Example2$Inner2.class
+      Removed classes/Example2.class
+      Removed classes/Example3.class
+      Removed classes/AdditionalClass3.class
+    </screen>
+
+    <para>
+
+    To ensure correct handling of <filename>.class</filename>
+    dependencies in all cases, you need to tell &SCons; which Java
+    version is being used.  This is needed because Java 1.5 changed
+    the <filename>.class</filename> file names for nested anonymous
+    inner classes.  Use the <varname>JAVAVERSION</varname> construction
+    variable to specify the version in use.  With Java 1.6, the
+    one-liner example can then be defined like this:
+
+    </para> 
+
+    <programlisting>
+      Java('classes', 'src', JAVAVERSION='1.6')
+    </programlisting>
+
+    <para>
+    See <varname>JAVAVERSION</varname> in the man page for more information.
+    </para>
+
+  </section>
+
+  <section>
+  <title>Building Java Archive (<filename>.jar</filename>) Files:  the &b-Jar; Builder</title>
+
+    <para>
+
+    After building the class files,
+    it's common to collect them into
+    a Java archive (<filename>.jar</filename>) file,
+    which you do by calling the &b-link-Jar; Builder method.
+    If you want to just collect all of the
+    class files within a subdirectory,
+    you can just specify that subdirectory
+    as the &b-Jar; source:
+
+    </para>
+
+    <programlisting>
+      Java(target = 'classes', source = 'src')
+      Jar(target = 'test.jar', source = 'classes')
+    </programlisting>
+
+    <para>
+
+    &SCons; will then pass that directory
+    to the &jar; command,
+    which will collect all of the underlying
+    <filename>.class</filename> files:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      javac -d classes -sourcepath src src/Example1.java src/Example2.java src/Example3.java
+      jar cf test.jar classes
+    </screen>
+
+    <para>
+
+    If you want to keep all of the
+    <filename>.class</filename> files
+    for multiple programs in one location,
+    and only archive some of them in
+    each <filename>.jar</filename> file,
+    you can pass the &b-Jar; builder a
+    list of files as its source.
+    It's extremely simple to create multiple
+    <filename>.jar</filename> files this way,
+    using the lists of target class files created
+    by calls to the &b-link-Java; builder
+    as sources to the various &b-Jar; calls:
+
+    </para>
+
+    <programlisting>
+      prog1_class_files = Java(target = 'classes', source = 'prog1')
+      prog2_class_files = Java(target = 'classes', source = 'prog2')
+      Jar(target = 'prog1.jar', source = prog1_class_files)
+      Jar(target = 'prog2.jar', source = prog2_class_files)
+    </programlisting>
+
+    <para>
+
+    This will then create
+    <filename>prog1.jar</filename>
+    and <filename>prog2.jar</filename>
+    next to the subdirectories
+    that contain their <filename>.java</filename> files:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      javac -d classes -sourcepath prog1 prog1/Example1.java prog1/Example2.java
+      javac -d classes -sourcepath prog2 prog2/Example3.java prog2/Example4.java
+      jar cf prog1.jar -C classes Example1.class -C classes Example2.class
+      jar cf prog2.jar -C classes Example3.class -C classes Example4.class
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Building C Header and Stub Files:  the &b-JavaH; Builder</title>
+
+    <para>
+
+    You can generate C header and source files
+    for implementing native methods,
+    by using the &b-link-JavaH; Builder.
+    There are several ways of using the &JavaH; Builder.
+    One typical invocation might look like:
+
+    </para>
+
+    <programlisting>
+      classes = Java(target = 'classes', source = 'src/pkg/sub')
+      JavaH(target = 'native', source = classes)
+    </programlisting>
+
+    <para>
+
+    The source is a list of class files generated by the
+    call to the &b-link-Java; Builder,
+    and the target is the output directory in
+    which we want the C header files placed.
+    The target
+    gets converted into the <option>-d</option>
+    when &SCons; runs &javah;:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      javac -d classes -sourcepath src/pkg/sub src/pkg/sub/Example1.java src/pkg/sub/Example2.java src/pkg/sub/Example3.java
+      javah -d native -classpath classes pkg.sub.Example1 pkg.sub.Example2 pkg.sub.Example3
+    </screen>
+
+    <para>
+
+    In this case,
+    the call to &javah;
+    will generate the header files
+    <filename>native/pkg_sub_Example1.h</filename>,
+    <filename>native/pkg_sub_Example2.h</filename>
+    and
+    <filename>native/pkg_sub_Example3.h</filename>.
+    Notice that &SCons; remembered that the class
+    files were generated with a target directory of
+    <filename>classes</filename>,
+    and that it then specified that target directory
+    as the <option>-classpath</option> option
+    to the call to &javah;.
+
+    </para>
+
+    <para>
+
+    Although it's more convenient to use
+    the list of class files returned by
+    the &b-Java; Builder
+    as the source of a call to the &b-JavaH; Builder,
+    you <emphasis>can</emphasis>
+    specify the list of class files
+    by hand, if you prefer.
+    If you do,
+    you need to set the
+    &cv-link-JAVACLASSDIR; construction variable
+    when calling &b-JavaH;:
+
+    </para>
+
+    <programlisting>
+      Java(target = 'classes', source = 'src/pkg/sub')
+      class_file_list = ['classes/pkg/sub/Example1.class',
+                         'classes/pkg/sub/Example2.class',
+                         'classes/pkg/sub/Example3.class']
+      JavaH(target = 'native', source = class_file_list, JAVACLASSDIR = 'classes')
+    </programlisting>
+
+    <para>
+
+    The &cv-JAVACLASSDIR; value then
+    gets converted into the <option>-classpath</option>
+    when &SCons; runs &javah;:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      javac -d classes -sourcepath src/pkg/sub src/pkg/sub/Example1.java src/pkg/sub/Example2.java src/pkg/sub/Example3.java
+      javah -d native -classpath classes pkg.sub.Example1 pkg.sub.Example2 pkg.sub.Example3
+    </screen>
+
+    <para>
+
+    Lastly, if you don't want a separate header file
+    generated for each source file,
+    you can specify an explicit File Node
+    as the target of the &b-JavaH; Builder:
+
+    </para>
+
+    <programlisting>
+      classes = Java(target = 'classes', source = 'src/pkg/sub')
+      JavaH(target = File('native.h'), source = classes)
+    </programlisting>
+
+    <para>
+
+    Because &SCons; assumes by default
+    that the target of the &b-JavaH; builder is a directory,
+    you need to use the &File; function
+    to make sure that &SCons; doesn't
+    create a directory named <filename>native.h</filename>.
+    When a file is used, though,
+    &SCons; correctly converts the file name
+    into the &javah; <option>-o</option> option:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      javac -d classes -sourcepath src/pkg/sub src/pkg/sub/Example1.java src/pkg/sub/Example2.java src/pkg/sub/Example3.java
+      javah -o native.h -classpath classes pkg.sub.Example1 pkg.sub.Example2 pkg.sub.Example3
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Building RMI Stub and Skeleton Class Files:  the &b-RMIC; Builder</title>
+
+    <para>
+
+    You can generate Remote Method Invocation stubs
+    by using the &b-link-RMIC; Builder.
+    The source is a list of directories,
+    typically returned by a call to the &b-link-Java; Builder,
+    and the target is an output directory
+    where the <filename>_Stub.class</filename>
+    and <filename>_Skel.class</filename> files will
+    be placed:
+
+    </para>
+
+    <programlisting>
+      classes = Java(target = 'classes', source = 'src/pkg/sub')
+      RMIC(target = 'outdir', source = classes)
+    </programlisting>
+
+    <para>
+
+    As it did with the &b-link-JavaH; Builder,
+    &SCons; remembers the class directory
+    and passes it as the <option>-classpath</option> option
+    to &rmic;:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      javac -d classes -sourcepath src/pkg/sub src/pkg/sub/Example1.java src/pkg/sub/Example2.java
+      rmic -d outdir -classpath classes pkg.sub.Example1 pkg.sub.Example2
+    </screen>
+
+    <para>
+
+    This example would generate the files
+    <filename>outdir/pkg/sub/Example1_Skel.class</filename>,
+    <filename>outdir/pkg/sub/Example1_Stub.class</filename>,
+    <filename>outdir/pkg/sub/Example2_Skel.class</filename> and
+    <filename>outdir/pkg/sub/Example2_Stub.class</filename>.
+
+    </para>
+
+  </section>
diff --git a/doc/user/less-simple.in b/doc/user/less-simple.in
new file mode 100644
index 0000000..e19ba13
--- /dev/null
+++ b/doc/user/less-simple.in
@@ -0,0 +1,623 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  In this chapter,
+  you will see several examples of
+  very simple build configurations using &SCons;,
+  which will demonstrate how easy
+  it is to use &SCons; to
+  build programs from several different programming languages
+  on different types of systems.
+
+  </para>
+
+  <section>
+  <title>Specifying the Name of the Target (Output) File</title>
+
+    <para>
+
+    You've seen that when you call the &b-link-Program; builder method,
+    it builds the resulting program with the same
+    base name as the source file.
+    That is, the following call to build an
+    executable program from the &hello_c; source file
+    will build an executable program named &hello; on POSIX systems,
+    and an executable program named &hello_exe; on Windows systems:
+
+    </para>
+
+    <programlisting>
+       Program('hello.c')
+    </programlisting>
+
+    <para>
+
+    If you want to build a program with
+    a different name than the base of the source file name,
+    you simply put the target file name
+    to the left of the source file name:
+
+    </para>
+
+    <scons_example name="target">
+       <file name="SConstruct" printme="1">
+       Program('new_hello', 'hello.c')
+       </file>
+       <file name="hello.c">
+       int main() { printf("Hello, world!\n"); }
+       </file>
+    </scons_example>
+
+    <para>
+
+    (&SCons; requires the target file name first,
+    followed by the source file name,
+    so that the order mimics that of an
+    assignment statement in most programming languages,
+    including Python:
+    <literal>"program = source files"</literal>.)
+
+    </para>
+
+    <para>
+
+    Now &SCons; will build an executable program
+    named &new_hello; when run on a POSIX system:
+
+    </para>
+
+    <scons_output example="target" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    And &SCons; will build an executable program
+    named &new_hello_exe; when run on a Windows system:
+
+    </para>
+
+    <scons_output example="target" os="win32">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Compiling Multiple Source Files</title>
+
+    <para>
+
+    You've just seen how to configure &SCons;
+    to compile a program from a single source file.
+    It's more common, of course,
+    that you'll need to build a program from
+    many input source files, not just one.
+    To do this, you need to put the
+    source files in a Python list
+    (enclosed in square brackets),
+    like so:
+
+    </para>
+
+    <scons_example name="ex2">
+       <file name="SConstruct" printme="1">
+       Program(['prog.c', 'file1.c', 'file2.c'])
+       </file>
+       <file name="prog.c">
+       int main() { printf("prog.c\n"); }
+       </file>
+       <file name="file1.c">
+       void file1() { printf("file1.c\n"); }
+       </file>
+       <file name="file2.c">
+       void file2() { printf("file2.c\n"); }
+       </file>
+    </scons_example>
+
+    <para>
+
+    A build of the above example would look like:
+
+    </para>
+
+    <scons_output example="ex2">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Notice that &SCons;
+    deduces the output program name
+    from the first source file specified
+    in the list--that is,
+    because the first source file was &prog_c;,
+    &SCons; will name the resulting program &prog;
+    (or &prog_exe; on a Windows system).
+    If you want to specify a different program name,
+    then (as we've seen in the previous section)
+    you slide the list of source files
+    over to the right
+    to make room for the output program file name.
+    (&SCons; puts the output file name to the left
+    of the source file names
+    so that the order mimics that of an
+    assignment statement:  "program = source files".)
+    This makes our example:
+
+    </para>
+
+    <scons_example name="ex3">
+       <file name="SConstruct" printme="1">
+       Program('program', ['prog.c', 'file1.c', 'file2.c'])
+       </file>
+       <file name="prog.c">
+       int main() { printf("prog.c\n"); }
+       </file>
+       <file name="file1.c">
+       void file1() { printf("file1.c\n"); }
+       </file>
+       <file name="file2.c">
+       void file2() { printf("file2.c\n"); }
+       </file>
+    </scons_example>
+
+    <para>
+
+    On Linux, a build of this example would look like:
+
+    </para>
+
+    <scons_output example="ex3" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Or on Windows:
+
+    </para>
+
+    <scons_output example="ex3" os="win32">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Making a list of files with &Glob;</title>
+
+    <para>
+
+    You can also use the &Glob; function to find all files matching a
+    certain template, using the standard shell pattern matching
+    characters <literal>*</literal>, <literal>?</literal>
+    and <literal>[abc]</literal> to match any of
+    <literal>a</literal>, <literal>b</literal> or <literal>c</literal>.
+    <literal>[!abc]</literal> is also supported,
+    to match any character <emphasis>except</emphasis>
+    <literal>a</literal>, <literal>b</literal> or <literal>c</literal>.
+    This makes many multi-source-file builds quite easy:
+
+    </para>
+
+    <sconstruct>
+       Program('program', Glob('*.c'))
+    </sconstruct>
+
+    <para>
+
+    The SCons man page has more details on using &Glob;
+    with variant directories
+    (see <xref linkend="chap-variants"></xref>, below)
+    and repositories
+    (see <xref linkend="chap-repositories"></xref>, below),
+    and returning strings rather than Nodes.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Specifying Single Files Vs. Lists of Files</title>
+
+    <para>
+
+    We've now shown you two ways to specify
+    the source for a program,
+    one with a list of files:
+
+    </para>
+
+    <sconstruct>
+       Program('hello', ['file1.c', 'file2.c'])
+    </sconstruct>
+
+    <para>
+
+    And one with a single file:
+
+    </para>
+
+    <sconstruct>
+       Program('hello', 'hello.c')
+    </sconstruct>
+
+    <para>
+
+    You could actually put a single file name in a list, too,
+    which you might prefer just for the sake of consistency:
+
+    </para>
+
+    <sconstruct>
+       Program('hello', ['hello.c'])
+    </sconstruct>
+
+    <para>
+
+    &SCons; functions will accept a single file name in either form.
+    In fact, internally, &SCons; treats all input as lists of files,
+    but allows you to omit the square brackets
+    to cut down a little on the typing
+    when there's only a single file name.
+
+    </para>
+
+    <important>
+    
+    <para>
+
+    Although &SCons; functions
+    are forgiving about whether or not you
+    use a string vs. a list for a single file name,
+    Python itself is more strict about
+    treating lists and strings differently.
+    So where &SCons; allows either
+    a string or list:
+
+    </para>
+
+    <sconstruct>
+       # The following two calls both work correctly:
+       Program('program1', 'program1.c')
+       Program('program2', ['program2.c'])
+    </sconstruct>
+
+    <para>
+
+    Trying to do "Python things" that mix strings and
+    lists will cause errors or lead to incorrect results:
+
+    </para>
+
+    <sconstruct>
+       common_sources = ['file1.c', 'file2.c']
+
+       # THE FOLLOWING IS INCORRECT AND GENERATES A PYTHON ERROR
+       # BECAUSE IT TRIES TO ADD A STRING TO A LIST:
+       Program('program1', common_sources + 'program1.c')
+
+       # The following works correctly, because it's adding two
+       # lists together to make another list.
+       Program('program2', common_sources + ['program2.c'])
+    </sconstruct>
+
+    </important>
+
+  </section>
+
+  <section>
+  <title>Making Lists of Files Easier to Read</title>
+
+    <para>
+
+    One drawback to the use of a Python list
+    for source files is that 
+    each file name must be enclosed in quotes
+    (either single quotes or double quotes).
+    This can get cumbersome and difficult to read
+    when the list of file names is long.
+    Fortunately, &SCons; and Python provide a number of ways
+    to make sure that
+    the &SConstruct; file stays easy to read.
+
+    </para>
+
+    <para>
+
+    To make long lists of file names
+    easier to deal with, &SCons; provides a
+    &Split; function
+    that takes a quoted list of file names,
+    with the names separated by spaces or other white-space characters,
+    and turns it into a list of separate file names.
+    Using the &Split; function turns the
+    previous example into:
+
+    </para>
+
+    <programlisting>
+       Program('program', Split('main.c file1.c file2.c'))
+    </programlisting>
+
+    <para>
+
+    (If you're already familiar with Python,
+    you'll have realized that this is similar to the
+    <function>split()</function> method
+    in the Python standard <function>string</function> module.
+    Unlike the <function>string.split()</function> method,
+    however, the &Split; function
+    does not require a string as input
+    and will wrap up a single non-string object in a list,
+    or return its argument untouched if it's already a list.
+    This comes in handy as a way to make sure
+    arbitrary values can be passed to &SCons; functions
+    without having to check the type of the variable by hand.)
+
+    </para>
+
+    <para>
+
+    Putting the call to the &Split; function
+    inside the &b-Program; call
+    can also be a little unwieldy.
+    A more readable alternative is to
+    assign the output from the &Split; call
+    to a variable name,
+    and then use the variable when calling the
+    &b-Program; function:
+
+    </para>
+
+    <programlisting>
+       src_files = Split('main.c file1.c file2.c')
+       Program('program', src_files)
+    </programlisting>
+
+    <para>
+
+    Lastly, the &Split; function
+    doesn't care how much white space separates
+    the file names in the quoted string.
+    This allows you to create lists of file
+    names that span multiple lines,
+    which often makes for easier editing:
+
+    </para>
+
+    <programlisting>
+       src_files = Split("""main.c
+                            file1.c
+                            file2.c""")
+       Program('program', src_files)
+    </programlisting>
+
+    <para>
+
+    (Note in this example that we used
+    the Python "triple-quote" syntax,
+    which allows a string to contain
+    multiple lines.
+    The three quotes can be either
+    single or double quotes.)
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Keyword Arguments</title>
+
+    <para>
+
+    &SCons; also allows you to identify
+    the output file and input source files
+    using Python keyword arguments.
+    The output file is known as the
+    <emphasis>target</emphasis>,
+    and the source file(s) are known (logically enough) as the
+    <emphasis>source</emphasis>.
+    The Python syntax for this is:
+
+    </para>
+
+    <programlisting>
+       src_files = Split('main.c file1.c file2.c')
+       Program(target = 'program', source = src_files)
+    </programlisting>
+
+    <para>
+
+    Because the keywords explicitly identify
+    what each argument is,
+    you can actually reverse the order if you prefer:
+
+    </para>
+
+    <programlisting>
+       src_files = Split('main.c file1.c file2.c')
+       Program(source = src_files, target = 'program')
+    </programlisting>
+
+    <para>
+
+    Whether or not you choose to use keyword arguments
+    to identify the target and source files,
+    and the order in which you specify them
+    when using keywords,
+    are purely personal choices;
+    &SCons; functions the same regardless.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Compiling Multiple Programs</title>
+
+    <para>
+
+    In order to compile multiple programs
+    within the same &SConstruct; file,
+    simply call the &Program; method
+    multiple times,
+    once for each program you need to build:
+
+    </para>
+
+    <scons_example name="ex4">
+       <file name="SConstruct" printme="1">
+       Program('foo.c')
+       Program('bar', ['bar1.c', 'bar2.c'])
+       </file>
+       <file name="foo.c">
+       int main() { printf("foo.c\n"); }
+       </file>
+       <file name="bar1.c">
+       int main() { printf("bar1.c\n"); }
+       </file>
+       <file name="bar2.c">
+       void bar2() { printf("bar2.c\n"); }
+       </file>
+    </scons_example>
+
+    <para>
+
+    &SCons; would then build the programs as follows:
+
+    </para>
+
+    <scons_output example="ex4">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Notice that &SCons; does not necessarily build the
+    programs in the same order in which you specify
+    them in the &SConstruct; file.
+    &SCons; does, however, recognize that
+    the individual object files must be built
+    before the resulting program can be built.
+    We'll discuss this in greater detail in
+    the "Dependencies" section, below.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Sharing Source Files Between Multiple Programs</title>
+
+    <para>
+
+    It's common to re-use code by sharing source files
+    between multiple programs.
+    One way to do this is to create a library
+    from the common source files,
+    which can then be linked into resulting programs.
+    (Creating libraries is discussed in
+    <xref linkend="chap-libraries"></xref>, below.)
+
+    </para>
+
+    <para>
+
+    A more straightforward, but perhaps less convenient,
+    way to share source files between multiple programs
+    is simply to include the common files
+    in the lists of source files for each program:
+
+    </para>
+
+    <scons_example name="ex5">
+       <file name="SConstruct" printme="1">
+       Program(Split('foo.c common1.c common2.c'))
+       Program('bar', Split('bar1.c bar2.c common1.c common2.c'))
+       </file>
+       <file name="foo.c">
+       int main() { printf("foo.c\n"); }
+       </file>
+       <file name="bar1.c">
+       int main() { printf("bar1.c\n"); }
+       </file>
+       <file name="bar2.c">
+       int bar2() { printf("bar2.c\n"); }
+       </file>
+       <file name="common1.c">
+       void common1() { printf("common1.c\n"); }
+       </file>
+       <file name="common2.c">
+       void common22() { printf("common2.c\n"); }
+       </file>
+    </scons_example>
+
+    <para>
+
+    &SCons; recognizes that the object files for
+    the &common1_c; and &common2_c; source files
+    each need to be built only once,
+    even though the resulting object files are
+    each linked in to both of the resulting executable programs:
+
+    </para>
+
+    <scons_output example="ex5">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    If two or more programs
+    share a lot of common source files,
+    repeating the common files in the list for each program
+    can be a maintenance problem when you need to change the
+    list of common files.
+    You can simplify this by creating a separate Python list
+    to hold the common file names,
+    and concatenating it with other lists
+    using the Python &plus; operator:
+
+    </para>
+
+    <programlisting>
+       common = ['common1.c', 'common2.c']
+       foo_files = ['foo.c'] + common
+       bar_files = ['bar1.c', 'bar2.c'] + common
+       Program('foo', foo_files)
+       Program('bar', bar_files)
+    </programlisting>
+
+    <para>
+
+    This is functionally equivalent to the previous example.
+
+    </para>
+
+  </section>
diff --git a/doc/user/less-simple.xml b/doc/user/less-simple.xml
new file mode 100644
index 0000000..57c61e2
--- /dev/null
+++ b/doc/user/less-simple.xml
@@ -0,0 +1,608 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  In this chapter,
+  you will see several examples of
+  very simple build configurations using &SCons;,
+  which will demonstrate how easy
+  it is to use &SCons; to
+  build programs from several different programming languages
+  on different types of systems.
+
+  </para>
+
+  <section>
+  <title>Specifying the Name of the Target (Output) File</title>
+
+    <para>
+
+    You've seen that when you call the &b-link-Program; builder method,
+    it builds the resulting program with the same
+    base name as the source file.
+    That is, the following call to build an
+    executable program from the &hello_c; source file
+    will build an executable program named &hello; on POSIX systems,
+    and an executable program named &hello_exe; on Windows systems:
+
+    </para>
+
+    <programlisting>
+       Program('hello.c')
+    </programlisting>
+
+    <para>
+
+    If you want to build a program with
+    a different name than the base of the source file name,
+    you simply put the target file name
+    to the left of the source file name:
+
+    </para>
+
+    <programlisting>
+       Program('new_hello', 'hello.c')
+    </programlisting>
+
+    <para>
+
+    (&SCons; requires the target file name first,
+    followed by the source file name,
+    so that the order mimics that of an
+    assignment statement in most programming languages,
+    including Python:
+    <literal>"program = source files"</literal>.)
+
+    </para>
+
+    <para>
+
+    Now &SCons; will build an executable program
+    named &new_hello; when run on a POSIX system:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       cc -o hello.o -c hello.c
+       cc -o new_hello hello.o
+    </screen>
+
+    <para>
+
+    And &SCons; will build an executable program
+    named &new_hello_exe; when run on a Windows system:
+
+    </para>
+
+    <screen>
+       C:\><userinput>scons -Q</userinput>
+       
+       scons: warning: No installed VCs
+       File "&lt;stdin&gt;", line 67, in __call__
+       
+       scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+       File "&lt;stdin&gt;", line 67, in __call__
+       cl /Fohello.obj /c hello.c /nologo
+       link /nologo /OUT:new_hello.exe hello.obj
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Compiling Multiple Source Files</title>
+
+    <para>
+
+    You've just seen how to configure &SCons;
+    to compile a program from a single source file.
+    It's more common, of course,
+    that you'll need to build a program from
+    many input source files, not just one.
+    To do this, you need to put the
+    source files in a Python list
+    (enclosed in square brackets),
+    like so:
+
+    </para>
+
+    <programlisting>
+       Program(['prog.c', 'file1.c', 'file2.c'])
+    </programlisting>
+
+    <para>
+
+    A build of the above example would look like:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       cc -o file1.o -c file1.c
+       cc -o file2.o -c file2.c
+       cc -o prog.o -c prog.c
+       cc -o prog prog.o file1.o file2.o
+    </screen>
+
+    <para>
+
+    Notice that &SCons;
+    deduces the output program name
+    from the first source file specified
+    in the list--that is,
+    because the first source file was &prog_c;,
+    &SCons; will name the resulting program &prog;
+    (or &prog_exe; on a Windows system).
+    If you want to specify a different program name,
+    then (as we've seen in the previous section)
+    you slide the list of source files
+    over to the right
+    to make room for the output program file name.
+    (&SCons; puts the output file name to the left
+    of the source file names
+    so that the order mimics that of an
+    assignment statement:  "program = source files".)
+    This makes our example:
+
+    </para>
+
+    <programlisting>
+       Program('program', ['prog.c', 'file1.c', 'file2.c'])
+    </programlisting>
+
+    <para>
+
+    On Linux, a build of this example would look like:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       cc -o file1.o -c file1.c
+       cc -o file2.o -c file2.c
+       cc -o prog.o -c prog.c
+       cc -o program prog.o file1.o file2.o
+    </screen>
+
+    <para>
+
+    Or on Windows:
+
+    </para>
+
+    <screen>
+       C:\><userinput>scons -Q</userinput>
+       
+       scons: warning: No installed VCs
+       File "&lt;stdin&gt;", line 67, in __call__
+       
+       scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+       File "&lt;stdin&gt;", line 67, in __call__
+       cl /Fofile1.obj /c file1.c /nologo
+       cl /Fofile2.obj /c file2.c /nologo
+       cl /Foprog.obj /c prog.c /nologo
+       link /nologo /OUT:program.exe prog.obj file1.obj file2.obj
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Making a list of files with &Glob;</title>
+
+    <para>
+
+    You can also use the &Glob; function to find all files matching a
+    certain template, using the standard shell pattern matching
+    characters <literal>*</literal>, <literal>?</literal>
+    and <literal>[abc]</literal> to match any of
+    <literal>a</literal>, <literal>b</literal> or <literal>c</literal>.
+    <literal>[!abc]</literal> is also supported,
+    to match any character <emphasis>except</emphasis>
+    <literal>a</literal>, <literal>b</literal> or <literal>c</literal>.
+    This makes many multi-source-file builds quite easy:
+
+    </para>
+
+    <programlisting>
+       Program('program', Glob('*.c'))
+    </programlisting>
+
+    <para>
+
+    The SCons man page has more details on using &Glob;
+    with variant directories
+    (see <xref linkend="chap-variants"></xref>, below)
+    and repositories
+    (see <xref linkend="chap-repositories"></xref>, below),
+    and returning strings rather than Nodes.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Specifying Single Files Vs. Lists of Files</title>
+
+    <para>
+
+    We've now shown you two ways to specify
+    the source for a program,
+    one with a list of files:
+
+    </para>
+
+    <programlisting>
+       Program('hello', ['file1.c', 'file2.c'])
+    </programlisting>
+
+    <para>
+
+    And one with a single file:
+
+    </para>
+
+    <programlisting>
+       Program('hello', 'hello.c')
+    </programlisting>
+
+    <para>
+
+    You could actually put a single file name in a list, too,
+    which you might prefer just for the sake of consistency:
+
+    </para>
+
+    <programlisting>
+       Program('hello', ['hello.c'])
+    </programlisting>
+
+    <para>
+
+    &SCons; functions will accept a single file name in either form.
+    In fact, internally, &SCons; treats all input as lists of files,
+    but allows you to omit the square brackets
+    to cut down a little on the typing
+    when there's only a single file name.
+
+    </para>
+
+    <important>
+    
+    <para>
+
+    Although &SCons; functions
+    are forgiving about whether or not you
+    use a string vs. a list for a single file name,
+    Python itself is more strict about
+    treating lists and strings differently.
+    So where &SCons; allows either
+    a string or list:
+
+    </para>
+
+    <programlisting>
+       # The following two calls both work correctly:
+       Program('program1', 'program1.c')
+       Program('program2', ['program2.c'])
+    </programlisting>
+
+    <para>
+
+    Trying to do "Python things" that mix strings and
+    lists will cause errors or lead to incorrect results:
+
+    </para>
+
+    <programlisting>
+       common_sources = ['file1.c', 'file2.c']
+
+       # THE FOLLOWING IS INCORRECT AND GENERATES A PYTHON ERROR
+       # BECAUSE IT TRIES TO ADD A STRING TO A LIST:
+       Program('program1', common_sources + 'program1.c')
+
+       # The following works correctly, because it's adding two
+       # lists together to make another list.
+       Program('program2', common_sources + ['program2.c'])
+    </programlisting>
+
+    </important>
+
+  </section>
+
+  <section>
+  <title>Making Lists of Files Easier to Read</title>
+
+    <para>
+
+    One drawback to the use of a Python list
+    for source files is that 
+    each file name must be enclosed in quotes
+    (either single quotes or double quotes).
+    This can get cumbersome and difficult to read
+    when the list of file names is long.
+    Fortunately, &SCons; and Python provide a number of ways
+    to make sure that
+    the &SConstruct; file stays easy to read.
+
+    </para>
+
+    <para>
+
+    To make long lists of file names
+    easier to deal with, &SCons; provides a
+    &Split; function
+    that takes a quoted list of file names,
+    with the names separated by spaces or other white-space characters,
+    and turns it into a list of separate file names.
+    Using the &Split; function turns the
+    previous example into:
+
+    </para>
+
+    <programlisting>
+       Program('program', Split('main.c file1.c file2.c'))
+    </programlisting>
+
+    <para>
+
+    (If you're already familiar with Python,
+    you'll have realized that this is similar to the
+    <function>split()</function> method
+    in the Python standard <function>string</function> module.
+    Unlike the <function>string.split()</function> method,
+    however, the &Split; function
+    does not require a string as input
+    and will wrap up a single non-string object in a list,
+    or return its argument untouched if it's already a list.
+    This comes in handy as a way to make sure
+    arbitrary values can be passed to &SCons; functions
+    without having to check the type of the variable by hand.)
+
+    </para>
+
+    <para>
+
+    Putting the call to the &Split; function
+    inside the &b-Program; call
+    can also be a little unwieldy.
+    A more readable alternative is to
+    assign the output from the &Split; call
+    to a variable name,
+    and then use the variable when calling the
+    &b-Program; function:
+
+    </para>
+
+    <programlisting>
+       src_files = Split('main.c file1.c file2.c')
+       Program('program', src_files)
+    </programlisting>
+
+    <para>
+
+    Lastly, the &Split; function
+    doesn't care how much white space separates
+    the file names in the quoted string.
+    This allows you to create lists of file
+    names that span multiple lines,
+    which often makes for easier editing:
+
+    </para>
+
+    <programlisting>
+       src_files = Split("""main.c
+                            file1.c
+                            file2.c""")
+       Program('program', src_files)
+    </programlisting>
+
+    <para>
+
+    (Note in this example that we used
+    the Python "triple-quote" syntax,
+    which allows a string to contain
+    multiple lines.
+    The three quotes can be either
+    single or double quotes.)
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Keyword Arguments</title>
+
+    <para>
+
+    &SCons; also allows you to identify
+    the output file and input source files
+    using Python keyword arguments.
+    The output file is known as the
+    <emphasis>target</emphasis>,
+    and the source file(s) are known (logically enough) as the
+    <emphasis>source</emphasis>.
+    The Python syntax for this is:
+
+    </para>
+
+    <programlisting>
+       src_files = Split('main.c file1.c file2.c')
+       Program(target = 'program', source = src_files)
+    </programlisting>
+
+    <para>
+
+    Because the keywords explicitly identify
+    what each argument is,
+    you can actually reverse the order if you prefer:
+
+    </para>
+
+    <programlisting>
+       src_files = Split('main.c file1.c file2.c')
+       Program(source = src_files, target = 'program')
+    </programlisting>
+
+    <para>
+
+    Whether or not you choose to use keyword arguments
+    to identify the target and source files,
+    and the order in which you specify them
+    when using keywords,
+    are purely personal choices;
+    &SCons; functions the same regardless.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Compiling Multiple Programs</title>
+
+    <para>
+
+    In order to compile multiple programs
+    within the same &SConstruct; file,
+    simply call the &Program; method
+    multiple times,
+    once for each program you need to build:
+
+    </para>
+
+    <programlisting>
+       Program('foo.c')
+       Program('bar', ['bar1.c', 'bar2.c'])
+    </programlisting>
+
+    <para>
+
+    &SCons; would then build the programs as follows:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       cc -o bar1.o -c bar1.c
+       cc -o bar2.o -c bar2.c
+       cc -o bar bar1.o bar2.o
+       cc -o foo.o -c foo.c
+       cc -o foo foo.o
+    </screen>
+
+    <para>
+
+    Notice that &SCons; does not necessarily build the
+    programs in the same order in which you specify
+    them in the &SConstruct; file.
+    &SCons; does, however, recognize that
+    the individual object files must be built
+    before the resulting program can be built.
+    We'll discuss this in greater detail in
+    the "Dependencies" section, below.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Sharing Source Files Between Multiple Programs</title>
+
+    <para>
+
+    It's common to re-use code by sharing source files
+    between multiple programs.
+    One way to do this is to create a library
+    from the common source files,
+    which can then be linked into resulting programs.
+    (Creating libraries is discussed in
+    <xref linkend="chap-libraries"></xref>, below.)
+
+    </para>
+
+    <para>
+
+    A more straightforward, but perhaps less convenient,
+    way to share source files between multiple programs
+    is simply to include the common files
+    in the lists of source files for each program:
+
+    </para>
+
+    <programlisting>
+       Program(Split('foo.c common1.c common2.c'))
+       Program('bar', Split('bar1.c bar2.c common1.c common2.c'))
+    </programlisting>
+
+    <para>
+
+    &SCons; recognizes that the object files for
+    the &common1_c; and &common2_c; source files
+    each need to be built only once,
+    even though the resulting object files are
+    each linked in to both of the resulting executable programs:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       cc -o bar1.o -c bar1.c
+       cc -o bar2.o -c bar2.c
+       cc -o common1.o -c common1.c
+       cc -o common2.o -c common2.c
+       cc -o bar bar1.o bar2.o common1.o common2.o
+       cc -o foo.o -c foo.c
+       cc -o foo foo.o common1.o common2.o
+    </screen>
+
+    <para>
+
+    If two or more programs
+    share a lot of common source files,
+    repeating the common files in the list for each program
+    can be a maintenance problem when you need to change the
+    list of common files.
+    You can simplify this by creating a separate Python list
+    to hold the common file names,
+    and concatenating it with other lists
+    using the Python &plus; operator:
+
+    </para>
+
+    <programlisting>
+       common = ['common1.c', 'common2.c']
+       foo_files = ['foo.c'] + common
+       bar_files = ['bar1.c', 'bar2.c'] + common
+       Program('foo', foo_files)
+       Program('bar', bar_files)
+    </programlisting>
+
+    <para>
+
+    This is functionally equivalent to the previous example.
+
+    </para>
+
+  </section>
diff --git a/doc/user/libraries.in b/doc/user/libraries.in
new file mode 100644
index 0000000..4cce091
--- /dev/null
+++ b/doc/user/libraries.in
@@ -0,0 +1,445 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  It's often useful to organize large software projects
+  by collecting parts of the software into one or more libraries.
+  &SCons; makes it easy to create libraries
+  and to use them in the programs.
+
+  </para>
+
+  <section>
+  <title>Building Libraries</title>
+
+    <para>
+
+    You build your own libraries by specifying &b-link-Library;
+    instead of &b-link-Program;:
+
+    </para>
+
+    <scons_example name="ex1" printme="1">
+      <file name="SConstruct" printme="1">
+      Library('foo', ['f1.c', 'f2.c', 'f3.c'])
+      </file>
+      <file name="f1.c">
+      void f1() { printf("f1.c\n"); }
+      </file>
+      <file name="f2.c">
+      void f2() { printf("f2.c\n"); }
+      </file>
+      <file name="f3.c">
+      void f3() { printf("f3.c\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    &SCons; uses the appropriate library prefix and suffix for your system.
+    So on POSIX or Linux systems,
+    the above example would build as follows
+    (although &ranlib; may not be called on all systems):
+
+    </para>
+
+    <scons_output example="ex1" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    On a Windows system,
+    a build of the above example would look like:
+
+    </para>
+
+    <scons_output example="ex1" os="win32">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The rules for the target name of the library
+    are similar to those for programs:
+    if you don't explicitly specify a target library name,
+    &SCons; will deduce one from the
+    name of the first source file specified,
+    and &SCons; will add an appropriate
+    file prefix and suffix if you leave them off.
+
+    </para>
+
+    <section>
+    <title>Building Libraries From Source Code or Object Files</title>
+
+      <para>
+
+      The previous example shows building a library from a
+      list of source files.
+      You can, however, also give the &b-link-Library; call
+      object files,
+      and it will correctly realize
+      In fact, you can arbitrarily mix source code files
+      and object files in the source list:
+
+      </para>
+
+      <scons_example name="objects" printme="1">
+        <file name="SConstruct" printme="1">
+        Library('foo', ['f1.c', 'f2.o', 'f3.c', 'f4.o'])
+        </file>
+        <file name="f1.c">
+        void f1() { printf("f1.c\n"); }
+        </file>
+        <file name="f2.o">
+        object file
+        </file>
+        <file name="f3.c">
+        void f3() { printf("f3.c\n"); }
+        </file>
+        <file name="f4.o">
+        object file
+        </file>
+      </scons_example>
+
+      <para>
+
+      And SCons realizes that only the source code files
+      must be compiled into object files
+      before creating the final library:
+
+      </para>
+
+      <scons_output example="objects" os="posix">
+        <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Of course, in this example, the object files
+      must already exist for the build to succeed.
+      See <xref linkend="chap-nodes"></xref>, below,
+      for information about how you can
+      build object files explicitly
+      and include the built files in a library.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Building Static Libraries Explicitly:  the &b-StaticLibrary; Builder</title>
+
+      <para>
+
+      The &b-link-Library; function builds a traditional static library.
+      If you want to be explicit about the type of library being built,
+      you can use the synonym &b-link-StaticLibrary; function
+      instead of &b-Library;:
+
+      </para>
+
+      <scons_example name="StaticLibrary" printme="1">
+        <file name="SConstruct" printme="1">
+        StaticLibrary('foo', ['f1.c', 'f2.c', 'f3.c'])
+        </file>
+      </scons_example>
+
+      <para>
+
+      There is no functional difference between the
+      &b-link-StaticLibrary; and &b-Library; functions.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Building Shared (DLL) Libraries:  the &b-SharedLibrary; Builder</title>
+
+      <para>
+
+      If you want to build a shared library (on POSIX systems)
+      or a DLL file (on Windows systems),
+      you use the &b-link-SharedLibrary; function:
+
+      </para>
+
+      <scons_example name="SharedLibrary" printme="1">
+        <file name="SConstruct" printme="1">
+        SharedLibrary('foo', ['f1.c', 'f2.c', 'f3.c'])
+        </file>
+        <file name="f1.c">
+        void f1() { printf("f1.c\n"); }
+        </file>
+        <file name="f2.c">
+        void f2() { printf("f2.c\n"); }
+        </file>
+        <file name="f3.c">
+        void f3() { printf("f3.c\n"); }
+        </file>
+      </scons_example>
+
+      <para>
+
+      The output on POSIX:
+
+      </para>
+
+      <scons_output example="SharedLibrary" os="posix">
+        <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      And the output on Windows:
+
+      </para>
+
+      <scons_output example="SharedLibrary" os="win32">
+        <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      Notice again that &SCons; takes care of
+      building the output file correctly,
+      adding the <literal>-shared</literal> option
+      for a POSIX compilation,
+      and the <literal>/dll</literal> option on Windows.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Linking with Libraries</title>
+
+    <para>
+
+    Usually, you build a library
+    because you want to link it with one or more programs.
+    You link libraries with a program by specifying
+    the libraries in the &cv-link-LIBS; construction variable,
+    and by specifying the directory in which
+    the library will be found in the 
+    &cv-link-LIBPATH; construction variable:
+
+    <!-- In the preceding paragraph, the "$" notation for
+         LIBS, LIBPATH etc. is used for the first time.
+         Maybe some words of explanation would be nice. -->
+
+    </para>
+
+    <scons_example name="ex2">
+      <file name="SConstruct" printme="1">
+      Library('foo', ['f1.c', 'f2.c', 'f3.c'])
+      Program('prog.c', LIBS=['foo', 'bar'], LIBPATH='.')
+      </file>
+      <file name="f1.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+      <file name="f2.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+      <file name="f3.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+      <file name="prog.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Notice, of course, that you don't need to specify a library
+    prefix (like <literal>lib</literal>)
+    or suffix (like <literal>.a</literal> or <literal>.lib</literal>).
+    &SCons; uses the correct prefix or suffix for the current system.
+
+    </para>
+
+    <para>
+
+    On a POSIX or Linux system,
+    a build of the above example would look like:
+
+    </para>
+
+    <scons_output example="ex2" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    On a Windows system,
+    a build of the above example would look like:
+
+    </para>
+
+    <scons_output example="ex2" os="win32">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    As usual, notice that &SCons; has taken care
+    of constructing the correct command lines
+    to link with the specified library on each system.
+
+    </para>
+
+    <para>
+
+    Note also that,
+    if you only have a single library to link with,
+    you can specify the library name in single string,
+    instead of a Python list,
+    so that:
+
+    </para>
+
+    <sconstruct>
+      Program('prog.c', LIBS='foo', LIBPATH='.')
+    </sconstruct>
+
+    <para>
+
+    is equivalent to:
+
+    </para>
+
+    <sconstruct>
+      Program('prog.c', LIBS=['foo'], LIBPATH='.')
+    </sconstruct>
+
+    <para>
+
+    This is similar to the way that &SCons;
+    handles either a string or a list to
+    specify a single source file.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Finding Libraries:  the &cv-LIBPATH; Construction Variable</title>
+
+    <para>
+
+    By default, the linker will only look in
+    certain system-defined directories for libraries.
+    &SCons; knows how to look for libraries
+    in directories that you specify with the
+    &cv-link-LIBPATH; construction variable.
+    &cv-LIBPATH; consists of a list of
+    directory names, like so:
+
+    </para>
+
+    <scons_example name="ex3">
+      <file name="SConstruct" printme="1">
+      Program('prog.c', LIBS = 'm',
+                        LIBPATH = ['/usr/lib', '/usr/local/lib'])
+      </file>
+      <file name="prog.c">
+      int main() { printf("prog.c\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Using a Python list is preferred because it's portable
+    across systems.  Alternatively, you could put all of
+    the directory names in a single string, separated by the
+    system-specific path separator character:
+    a colon on POSIX systems:
+
+    </para>
+
+    <sconstruct>
+      LIBPATH = '/usr/lib:/usr/local/lib'
+    </sconstruct>
+
+    <para>
+
+    or a semi-colon on Windows systems:
+
+    </para>
+
+    <sconstruct>
+      LIBPATH = 'C:\\lib;D:\\lib'
+    </sconstruct>
+
+    <para>
+
+    (Note that Python requires that the backslash
+    separators in a Windows path name
+    be escaped within strings.)
+
+    </para>
+
+    <para>
+
+    When the linker is executed,
+    &SCons; will create appropriate flags
+    so that the linker will look for
+    libraries in the same directories as &SCons;.
+    So on a POSIX or Linux system,
+    a build of the above example would look like:
+
+    </para>
+
+    <scons_output example="ex3" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    On a Windows system,
+    a build of the above example would look like:
+
+    </para>
+
+    <scons_output example="ex3" os="win32">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+    <!-- The link command is too wide in the PDF version. 
+         There are some other examples of this throughout the document. -->
+
+    <para>
+
+    Note again that &SCons; has taken care of
+    the system-specific details of creating
+    the right command-line options.
+
+    </para>
+
+  </section>
diff --git a/doc/user/libraries.xml b/doc/user/libraries.xml
new file mode 100644
index 0000000..e3821ce
--- /dev/null
+++ b/doc/user/libraries.xml
@@ -0,0 +1,451 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  It's often useful to organize large software projects
+  by collecting parts of the software into one or more libraries.
+  &SCons; makes it easy to create libraries
+  and to use them in the programs.
+
+  </para>
+
+  <section>
+  <title>Building Libraries</title>
+
+    <para>
+
+    You build your own libraries by specifying &b-link-Library;
+    instead of &b-link-Program;:
+
+    </para>
+
+    <programlisting>
+      Library('foo', ['f1.c', 'f2.c', 'f3.c'])
+    </programlisting>
+
+    <para>
+
+    &SCons; uses the appropriate library prefix and suffix for your system.
+    So on POSIX or Linux systems,
+    the above example would build as follows
+    (although &ranlib; may not be called on all systems):
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o f1.o -c f1.c
+      cc -o f2.o -c f2.c
+      cc -o f3.o -c f3.c
+      ar rc libfoo.a f1.o f2.o f3.o
+      ranlib libfoo.a
+    </screen>
+
+    <para>
+
+    On a Windows system,
+    a build of the above example would look like:
+
+    </para>
+
+    <screen>
+      C:\><userinput>scons -Q</userinput>
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      cl /Fof1.obj /c f1.c /nologo
+      cl /Fof2.obj /c f2.c /nologo
+      cl /Fof3.obj /c f3.c /nologo
+      lib /nologo /OUT:foo.lib f1.obj f2.obj f3.obj
+    </screen>
+
+    <para>
+
+    The rules for the target name of the library
+    are similar to those for programs:
+    if you don't explicitly specify a target library name,
+    &SCons; will deduce one from the
+    name of the first source file specified,
+    and &SCons; will add an appropriate
+    file prefix and suffix if you leave them off.
+
+    </para>
+
+    <section>
+    <title>Building Libraries From Source Code or Object Files</title>
+
+      <para>
+
+      The previous example shows building a library from a
+      list of source files.
+      You can, however, also give the &b-link-Library; call
+      object files,
+      and it will correctly realize
+      In fact, you can arbitrarily mix source code files
+      and object files in the source list:
+
+      </para>
+
+      <programlisting>
+        Library('foo', ['f1.c', 'f2.o', 'f3.c', 'f4.o'])
+      </programlisting>
+
+      <para>
+
+      And SCons realizes that only the source code files
+      must be compiled into object files
+      before creating the final library:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q</userinput>
+        cc -o f1.o -c f1.c
+        cc -o f3.o -c f3.c
+        ar rc libfoo.a f1.o f2.o f3.o f4.o
+        ranlib libfoo.a
+      </screen>
+
+      <para>
+
+      Of course, in this example, the object files
+      must already exist for the build to succeed.
+      See <xref linkend="chap-nodes"></xref>, below,
+      for information about how you can
+      build object files explicitly
+      and include the built files in a library.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Building Static Libraries Explicitly:  the &b-StaticLibrary; Builder</title>
+
+      <para>
+
+      The &b-link-Library; function builds a traditional static library.
+      If you want to be explicit about the type of library being built,
+      you can use the synonym &b-link-StaticLibrary; function
+      instead of &b-Library;:
+
+      </para>
+
+      <programlisting>
+        StaticLibrary('foo', ['f1.c', 'f2.c', 'f3.c'])
+      </programlisting>
+
+      <para>
+
+      There is no functional difference between the
+      &b-link-StaticLibrary; and &b-Library; functions.
+
+      </para>
+
+    </section>
+
+    <section>
+    <title>Building Shared (DLL) Libraries:  the &b-SharedLibrary; Builder</title>
+
+      <para>
+
+      If you want to build a shared library (on POSIX systems)
+      or a DLL file (on Windows systems),
+      you use the &b-link-SharedLibrary; function:
+
+      </para>
+
+      <programlisting>
+        SharedLibrary('foo', ['f1.c', 'f2.c', 'f3.c'])
+      </programlisting>
+
+      <para>
+
+      The output on POSIX:
+
+      </para>
+
+      <screen>
+        % <userinput>scons -Q</userinput>
+        cc -o f1.os -c f1.c
+        cc -o f2.os -c f2.c
+        cc -o f3.os -c f3.c
+        cc -o libfoo.so -shared f1.os f2.os f3.os
+      </screen>
+
+      <para>
+
+      And the output on Windows:
+
+      </para>
+
+      <screen>
+        C:\><userinput>scons -Q</userinput>
+        
+        scons: warning: No installed VCs
+        File "&lt;stdin&gt;", line 67, in __call__
+        
+        scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+        File "&lt;stdin&gt;", line 67, in __call__
+        cl /Fof1.obj /c f1.c /nologo
+        cl /Fof2.obj /c f2.c /nologo
+        cl /Fof3.obj /c f3.c /nologo
+        link /nologo /dll /out:foo.dll /implib:foo.lib f1.obj f2.obj f3.obj
+        RegServerFunc(target, source, env)
+      </screen>
+
+      <para>
+
+      Notice again that &SCons; takes care of
+      building the output file correctly,
+      adding the <literal>-shared</literal> option
+      for a POSIX compilation,
+      and the <literal>/dll</literal> option on Windows.
+
+      </para>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Linking with Libraries</title>
+
+    <para>
+
+    Usually, you build a library
+    because you want to link it with one or more programs.
+    You link libraries with a program by specifying
+    the libraries in the &cv-link-LIBS; construction variable,
+    and by specifying the directory in which
+    the library will be found in the 
+    &cv-link-LIBPATH; construction variable:
+
+    <!-- In the preceding paragraph, the "$" notation for
+         LIBS, LIBPATH etc. is used for the first time.
+         Maybe some words of explanation would be nice. -->
+
+    </para>
+
+    <programlisting>
+      Library('foo', ['f1.c', 'f2.c', 'f3.c'])
+      Program('prog.c', LIBS=['foo', 'bar'], LIBPATH='.')
+    </programlisting>
+
+    <para>
+
+    Notice, of course, that you don't need to specify a library
+    prefix (like <literal>lib</literal>)
+    or suffix (like <literal>.a</literal> or <literal>.lib</literal>).
+    &SCons; uses the correct prefix or suffix for the current system.
+
+    </para>
+
+    <para>
+
+    On a POSIX or Linux system,
+    a build of the above example would look like:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o f1.o -c f1.c
+      cc -o f2.o -c f2.c
+      cc -o f3.o -c f3.c
+      ar rc libfoo.a f1.o f2.o f3.o
+      ranlib libfoo.a
+      cc -o prog.o -c prog.c
+      cc -o prog prog.o -L. -lfoo -lbar
+    </screen>
+
+    <para>
+
+    On a Windows system,
+    a build of the above example would look like:
+
+    </para>
+
+    <screen>
+      C:\><userinput>scons -Q</userinput>
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      cl /Fof1.obj /c f1.c /nologo
+      cl /Fof2.obj /c f2.c /nologo
+      cl /Fof3.obj /c f3.c /nologo
+      lib /nologo /OUT:foo.lib f1.obj f2.obj f3.obj
+      cl /Foprog.obj /c prog.c /nologo
+      link /nologo /OUT:prog.exe /LIBPATH:. foo.lib bar.lib prog.obj
+    </screen>
+
+    <para>
+
+    As usual, notice that &SCons; has taken care
+    of constructing the correct command lines
+    to link with the specified library on each system.
+
+    </para>
+
+    <para>
+
+    Note also that,
+    if you only have a single library to link with,
+    you can specify the library name in single string,
+    instead of a Python list,
+    so that:
+
+    </para>
+
+    <programlisting>
+      Program('prog.c', LIBS='foo', LIBPATH='.')
+    </programlisting>
+
+    <para>
+
+    is equivalent to:
+
+    </para>
+
+    <programlisting>
+      Program('prog.c', LIBS=['foo'], LIBPATH='.')
+    </programlisting>
+
+    <para>
+
+    This is similar to the way that &SCons;
+    handles either a string or a list to
+    specify a single source file.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Finding Libraries:  the &cv-LIBPATH; Construction Variable</title>
+
+    <para>
+
+    By default, the linker will only look in
+    certain system-defined directories for libraries.
+    &SCons; knows how to look for libraries
+    in directories that you specify with the
+    &cv-link-LIBPATH; construction variable.
+    &cv-LIBPATH; consists of a list of
+    directory names, like so:
+
+    </para>
+
+    <programlisting>
+      Program('prog.c', LIBS = 'm',
+                        LIBPATH = ['/usr/lib', '/usr/local/lib'])
+    </programlisting>
+
+    <para>
+
+    Using a Python list is preferred because it's portable
+    across systems.  Alternatively, you could put all of
+    the directory names in a single string, separated by the
+    system-specific path separator character:
+    a colon on POSIX systems:
+
+    </para>
+
+    <programlisting>
+      LIBPATH = '/usr/lib:/usr/local/lib'
+    </programlisting>
+
+    <para>
+
+    or a semi-colon on Windows systems:
+
+    </para>
+
+    <programlisting>
+      LIBPATH = 'C:\\lib;D:\\lib'
+    </programlisting>
+
+    <para>
+
+    (Note that Python requires that the backslash
+    separators in a Windows path name
+    be escaped within strings.)
+
+    </para>
+
+    <para>
+
+    When the linker is executed,
+    &SCons; will create appropriate flags
+    so that the linker will look for
+    libraries in the same directories as &SCons;.
+    So on a POSIX or Linux system,
+    a build of the above example would look like:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o prog.o -c prog.c
+      cc -o prog prog.o -L/usr/lib -L/usr/local/lib -lm
+    </screen>
+
+    <para>
+
+    On a Windows system,
+    a build of the above example would look like:
+
+    </para>
+
+    <screen>
+      C:\><userinput>scons -Q</userinput>
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      cl /Foprog.obj /c prog.c /nologo
+      link /nologo /OUT:prog.exe /LIBPATH:\usr\lib /LIBPATH:\usr\local\lib m.lib prog.obj
+    </screen>
+    <!-- The link command is too wide in the PDF version. 
+         There are some other examples of this throughout the document. -->
+
+    <para>
+
+    Note again that &SCons; has taken care of
+    the system-specific details of creating
+    the right command-line options.
+
+    </para>
+
+  </section>
diff --git a/doc/user/main.in b/doc/user/main.in
new file mode 100644
index 0000000..949a90a
--- /dev/null
+++ b/doc/user/main.in
@@ -0,0 +1,385 @@
+<?xml version="1.0"?>
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
+"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd"
+[
+
+    <!ENTITY % version SYSTEM "../version.xml">
+    %version;
+
+    <!ENTITY % scons SYSTEM "../scons.mod">
+    %scons;
+
+    <!ENTITY % builders-mod SYSTEM "builders.mod">
+    %builders-mod;
+
+    <!ENTITY % tools-mod SYSTEM "tools.mod">
+    %tools-mod;
+
+    <!ENTITY % variables-mod SYSTEM "variables.mod">
+    %variables-mod;
+
+    <!ENTITY actions SYSTEM "actions.xml">
+    <!ENTITY alias SYSTEM "alias.xml">
+    <!ENTITY ant SYSTEM "ant.xml">
+    <!ENTITY build-install SYSTEM "build-install.xml">
+    <!ENTITY builders SYSTEM "builders.xml">
+    <!ENTITY builders-built-in SYSTEM "builders-built-in.xml">
+    <!ENTITY builders-commands SYSTEM "builders-commands.xml">
+    <!ENTITY builders-writing SYSTEM "builders-writing.xml">
+    <!ENTITY add-method SYSTEM "add-method.xml">
+    <!ENTITY caching SYSTEM "caching.xml">
+    <!ENTITY command-line SYSTEM "command-line.xml">
+    <!ENTITY copyright SYSTEM "copyright.xml">
+    <!ENTITY depends SYSTEM "depends.xml">
+    <!ENTITY environments SYSTEM "environments.xml">
+    <!ENTITY errors SYSTEM "errors.xml">
+    <!ENTITY example SYSTEM "example.xml">
+    <!ENTITY factories SYSTEM "factories.xml">
+    <!ENTITY file-removal SYSTEM "file-removal.xml">
+    <!ENTITY hierarchy SYSTEM "hierarchy.xml">
+    <!ENTITY java SYSTEM "java.xml">
+    <!ENTITY install SYSTEM "install.xml">
+    <!ENTITY less-simple SYSTEM "less-simple.xml">
+    <!ENTITY libraries SYSTEM "libraries.xml">
+    <!ENTITY make SYSTEM "make.xml">
+    <!ENTITY mergeflags SYSTEM "mergeflags.xml">
+    <!ENTITY misc SYSTEM "misc.xml">
+    <!ENTITY nodes SYSTEM "nodes.xml">
+    <!ENTITY output SYSTEM "output.xml">
+    <!ENTITY parseconfig SYSTEM "parseconfig.xml">
+    <!ENTITY parseflags SYSTEM "parseflags.xml">
+    <!ENTITY preface SYSTEM "preface.xml">
+    <!ENTITY python SYSTEM "python.xml">
+    <!ENTITY repositories SYSTEM "repositories.xml">
+    <!ENTITY run SYSTEM "run.xml">
+    <!ENTITY scanners SYSTEM "scanners.xml">
+    <!ENTITY sconf SYSTEM "sconf.xml">
+    <!ENTITY separate SYSTEM "separate.xml">
+    <!ENTITY simple SYSTEM "simple.xml">
+    <!ENTITY sourcecode SYSTEM "sourcecode.xml">
+    <!ENTITY tasks SYSTEM "tasks.xml">
+    <!ENTITY tools SYSTEM "tools.xml">
+    <!ENTITY troubleshoot SYSTEM "troubleshoot.xml">
+    <!ENTITY variables-xml SYSTEM "variables.xml">
+    <!ENTITY variants SYSTEM "variants.xml">
+
+    <!ENTITY builders-gen SYSTEM "builders.gen">
+    <!ENTITY tools-gen SYSTEM "tools.gen">
+    <!ENTITY variables-gen SYSTEM "variables.gen">
+
+]>
+
+  <!--
+
+  XXX FindFile()
+  XXX FindPathDirs()
+  XXX GetBuildPath()
+  XXX GetLaunchDir()
+
+  XXX ParseDepends()
+  XXX Platform()
+  XXX SConsignFile()
+  XXX Tools()
+
+  XXX GetOption('duplicate')
+  XXX SetOption('duplicate')
+  XXX - - duplicate=
+
+  XXX CheckTypeSize()
+
+  XXX - - diskcheck=
+
+  XXX - - warn=
+
+  -->
+
+<book>
+  <bookinfo>
+    <title>SCons User Guide &buildversion;</title>
+
+    <author>
+      <firstname>Steven</firstname>
+      <surname>Knight</surname>
+    </author>
+
+    <edition>Revision &buildrevision; (&builddate;)</edition>
+
+    <pubdate>2004, 2005, 2006, 2007, 2008</pubdate>
+
+    <copyright>
+      <year>2004, 2005, 2006, 2007, 2008</year>
+      <holder>Steven Knight</holder>
+    </copyright>
+
+    <legalnotice>
+      &copyright;
+    </legalnotice>
+
+    <releaseinfo>version &buildversion;</releaseinfo>
+
+  </bookinfo>
+
+  <preface id="chap-preface">
+    <title>Preface</title>
+    &preface;
+  </preface>
+
+  <chapter id="chap-build-install">
+    <title>Building and Installing &SCons;</title>
+    &build-install;
+  </chapter>
+
+  <chapter id="chap-simple">
+    <title>Simple Builds</title>
+    &simple;
+  </chapter>
+
+  <chapter id="chap-less-simple">
+    <title>Less Simple Things to Do With Builds</title>
+    &less-simple;
+  </chapter>
+
+  <chapter id="chap-libraries">
+    <title>Building and Linking with Libraries</title>
+    &libraries;
+  </chapter>
+
+  <chapter id="chap-nodes">
+    <title>Node Objects</title>
+    &nodes;
+  </chapter>
+
+  <chapter id="chap-depends">
+    <title>Dependencies</title>
+    &depends;
+  </chapter>
+
+  <chapter id="chap-environments">
+    <title>Environments</title>
+    &environments;
+  </chapter>
+
+  <!-- These next three sections should be combined into one chapter -->
+  <chapter id="chap-mergeflags">
+    <title>Merging Options into the Environment: the &MergeFlags; Function</title>
+    &mergeflags;
+  </chapter>
+  <chapter id="chap-parseflags">
+    <title>Separating Compile Arguments into their Variables:  the &ParseFlags; Function</title>
+    &parseflags;
+  </chapter>
+  <chapter id="chap-parseconfig">
+    <title>Finding Installed Library Information:  the &ParseConfig; Function</title>
+    &parseconfig;
+  </chapter>
+
+  <chapter id="chap-output">
+    <title>Controlling Build Output</title>
+    &output;
+  </chapter>
+
+  <chapter id="chap-command-line">
+    <title>Controlling a Build From the Command Line</title>
+    &command-line;
+  </chapter>
+
+  <chapter id="chap-install">
+    <title>Installing Files in Other Directories:  the &Install; Builder</title>
+    &install;
+  </chapter>
+
+  <chapter id="chap-factories">
+    <title>Platform-Independent File System Manipulation</title>
+    &factories;
+  </chapter>
+
+  <chapter id="chap-file-removal">
+    <title>Controlling Removal of Targets</title>
+    &file-removal;
+  </chapter>
+
+  <chapter id="chap-hierarchical">
+    <title>Hierarchical Builds</title>
+    &hierarchy;
+  </chapter>
+
+  <chapter id="chap-separate">
+    <title>Separating Source and Build Directories</title>
+    &separate;
+  </chapter>
+
+  <chapter id="chap-variants">
+    <title>Variant Builds</title>
+    &variants;
+  </chapter>
+
+  <!--
+
+  <chapter id="chap-builders-built-in">
+    <title>Built-In Builders</title>
+    &builders-built-in;
+  </chapter>
+
+  -->
+
+  <chapter id="chap-builders-writing">
+    <title>Writing Your Own Builders</title>
+    &builders-writing;
+  </chapter>
+
+  <chapter id="chap-builders-commands">
+    <title>Not Writing a Builder:  the &Command; Builder</title>
+    &builders-commands;
+  </chapter>
+
+  <chapter id="chap-add-method">
+    <title>Pseudo-Builders:  the AddMethod function</title>
+    &add-method;
+  </chapter>
+
+  <!--
+
+  XXX Action()
+  XXX AddPostAction()
+  XXX AddPreAction()
+
+  <chapter id="chap-actions">
+    <title>&SCons; Actions</title>
+    &actions;
+  </chapter>
+
+  -->
+
+  <chapter id="chap-scanners">
+    <title>Writing Scanners</title>
+    &scanners;
+  </chapter>
+
+  <chapter id="chap-repositories">
+    <title>Building From Code Repositories</title>
+    &repositories;
+  </chapter>
+
+  <chapter id="chap-sconf">
+    <title>Multi-Platform Configuration (&Autoconf; Functionality)</title>
+    &sconf;
+  </chapter>
+
+  <!--
+
+  <chapter id="chap-sourcecode">
+    <title>Fetching Files From Source Code Management Systems</title>
+    &sourcecode;
+  </chapter>
+
+  -->
+
+  <chapter id="chap-caching">
+    <title>Caching Built Files</title>
+    &caching;
+  </chapter>
+
+  <chapter id="chap-alias">
+    <title>Alias Targets</title>
+    &alias;
+  </chapter>
+
+  <chapter id="chap-java">
+    <title>Java Builds</title>
+    &java;
+  </chapter>
+
+  <!--
+
+  <chapter id="chap-run">
+    <title>How to Run &SCons;</title>
+    &run;
+  </chapter>
+
+  -->
+
+  <chapter id="chap-misc">
+    <title>Miscellaneous Functionality</title>
+    &misc;
+  </chapter>
+
+  <chapter id="chap-troubleshooting">
+    <title>Troubleshooting</title>
+    &troubleshoot;
+  </chapter>
+
+  <appendix id="app-variables">
+    <title>Construction Variables</title>
+    &variables-xml;
+  </appendix>
+
+  <appendix id="app-builders">
+    <title>Builders</title>
+    &builders;
+  </appendix>
+
+  <appendix id="app-tools">
+    <title>Tools</title>
+    &tools;
+  </appendix>
+
+  <appendix id="app-tasks">
+    <title>Handling Common Tasks</title>
+    &tasks;
+  </appendix>
+
+  <!--
+
+  <appendix id="app-python">
+    <title>Python Overview</title>
+    &example;
+  </appendix>
+
+  <appendix id="app-example">
+    <title>Complex &SCons; Example</title>
+    &example;
+  </appendix>
+
+  <appendix id="app-make">
+    <title>Converting From Make</title>
+    &make;
+  </appendix>
+
+  <appendix id="app-cons">
+    <title>Converting From Cons</title>
+    &cons;
+  </appendix>
+
+  <appendix id="app-ant">
+    <title>Converting From Ant</title>
+    &ant;
+  </appendix>
+
+  -->
+
+</book>
diff --git a/doc/user/main.xml b/doc/user/main.xml
new file mode 100644
index 0000000..949a90a
--- /dev/null
+++ b/doc/user/main.xml
@@ -0,0 +1,385 @@
+<?xml version="1.0"?>
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
+"http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd"
+[
+
+    <!ENTITY % version SYSTEM "../version.xml">
+    %version;
+
+    <!ENTITY % scons SYSTEM "../scons.mod">
+    %scons;
+
+    <!ENTITY % builders-mod SYSTEM "builders.mod">
+    %builders-mod;
+
+    <!ENTITY % tools-mod SYSTEM "tools.mod">
+    %tools-mod;
+
+    <!ENTITY % variables-mod SYSTEM "variables.mod">
+    %variables-mod;
+
+    <!ENTITY actions SYSTEM "actions.xml">
+    <!ENTITY alias SYSTEM "alias.xml">
+    <!ENTITY ant SYSTEM "ant.xml">
+    <!ENTITY build-install SYSTEM "build-install.xml">
+    <!ENTITY builders SYSTEM "builders.xml">
+    <!ENTITY builders-built-in SYSTEM "builders-built-in.xml">
+    <!ENTITY builders-commands SYSTEM "builders-commands.xml">
+    <!ENTITY builders-writing SYSTEM "builders-writing.xml">
+    <!ENTITY add-method SYSTEM "add-method.xml">
+    <!ENTITY caching SYSTEM "caching.xml">
+    <!ENTITY command-line SYSTEM "command-line.xml">
+    <!ENTITY copyright SYSTEM "copyright.xml">
+    <!ENTITY depends SYSTEM "depends.xml">
+    <!ENTITY environments SYSTEM "environments.xml">
+    <!ENTITY errors SYSTEM "errors.xml">
+    <!ENTITY example SYSTEM "example.xml">
+    <!ENTITY factories SYSTEM "factories.xml">
+    <!ENTITY file-removal SYSTEM "file-removal.xml">
+    <!ENTITY hierarchy SYSTEM "hierarchy.xml">
+    <!ENTITY java SYSTEM "java.xml">
+    <!ENTITY install SYSTEM "install.xml">
+    <!ENTITY less-simple SYSTEM "less-simple.xml">
+    <!ENTITY libraries SYSTEM "libraries.xml">
+    <!ENTITY make SYSTEM "make.xml">
+    <!ENTITY mergeflags SYSTEM "mergeflags.xml">
+    <!ENTITY misc SYSTEM "misc.xml">
+    <!ENTITY nodes SYSTEM "nodes.xml">
+    <!ENTITY output SYSTEM "output.xml">
+    <!ENTITY parseconfig SYSTEM "parseconfig.xml">
+    <!ENTITY parseflags SYSTEM "parseflags.xml">
+    <!ENTITY preface SYSTEM "preface.xml">
+    <!ENTITY python SYSTEM "python.xml">
+    <!ENTITY repositories SYSTEM "repositories.xml">
+    <!ENTITY run SYSTEM "run.xml">
+    <!ENTITY scanners SYSTEM "scanners.xml">
+    <!ENTITY sconf SYSTEM "sconf.xml">
+    <!ENTITY separate SYSTEM "separate.xml">
+    <!ENTITY simple SYSTEM "simple.xml">
+    <!ENTITY sourcecode SYSTEM "sourcecode.xml">
+    <!ENTITY tasks SYSTEM "tasks.xml">
+    <!ENTITY tools SYSTEM "tools.xml">
+    <!ENTITY troubleshoot SYSTEM "troubleshoot.xml">
+    <!ENTITY variables-xml SYSTEM "variables.xml">
+    <!ENTITY variants SYSTEM "variants.xml">
+
+    <!ENTITY builders-gen SYSTEM "builders.gen">
+    <!ENTITY tools-gen SYSTEM "tools.gen">
+    <!ENTITY variables-gen SYSTEM "variables.gen">
+
+]>
+
+  <!--
+
+  XXX FindFile()
+  XXX FindPathDirs()
+  XXX GetBuildPath()
+  XXX GetLaunchDir()
+
+  XXX ParseDepends()
+  XXX Platform()
+  XXX SConsignFile()
+  XXX Tools()
+
+  XXX GetOption('duplicate')
+  XXX SetOption('duplicate')
+  XXX - - duplicate=
+
+  XXX CheckTypeSize()
+
+  XXX - - diskcheck=
+
+  XXX - - warn=
+
+  -->
+
+<book>
+  <bookinfo>
+    <title>SCons User Guide &buildversion;</title>
+
+    <author>
+      <firstname>Steven</firstname>
+      <surname>Knight</surname>
+    </author>
+
+    <edition>Revision &buildrevision; (&builddate;)</edition>
+
+    <pubdate>2004, 2005, 2006, 2007, 2008</pubdate>
+
+    <copyright>
+      <year>2004, 2005, 2006, 2007, 2008</year>
+      <holder>Steven Knight</holder>
+    </copyright>
+
+    <legalnotice>
+      &copyright;
+    </legalnotice>
+
+    <releaseinfo>version &buildversion;</releaseinfo>
+
+  </bookinfo>
+
+  <preface id="chap-preface">
+    <title>Preface</title>
+    &preface;
+  </preface>
+
+  <chapter id="chap-build-install">
+    <title>Building and Installing &SCons;</title>
+    &build-install;
+  </chapter>
+
+  <chapter id="chap-simple">
+    <title>Simple Builds</title>
+    &simple;
+  </chapter>
+
+  <chapter id="chap-less-simple">
+    <title>Less Simple Things to Do With Builds</title>
+    &less-simple;
+  </chapter>
+
+  <chapter id="chap-libraries">
+    <title>Building and Linking with Libraries</title>
+    &libraries;
+  </chapter>
+
+  <chapter id="chap-nodes">
+    <title>Node Objects</title>
+    &nodes;
+  </chapter>
+
+  <chapter id="chap-depends">
+    <title>Dependencies</title>
+    &depends;
+  </chapter>
+
+  <chapter id="chap-environments">
+    <title>Environments</title>
+    &environments;
+  </chapter>
+
+  <!-- These next three sections should be combined into one chapter -->
+  <chapter id="chap-mergeflags">
+    <title>Merging Options into the Environment: the &MergeFlags; Function</title>
+    &mergeflags;
+  </chapter>
+  <chapter id="chap-parseflags">
+    <title>Separating Compile Arguments into their Variables:  the &ParseFlags; Function</title>
+    &parseflags;
+  </chapter>
+  <chapter id="chap-parseconfig">
+    <title>Finding Installed Library Information:  the &ParseConfig; Function</title>
+    &parseconfig;
+  </chapter>
+
+  <chapter id="chap-output">
+    <title>Controlling Build Output</title>
+    &output;
+  </chapter>
+
+  <chapter id="chap-command-line">
+    <title>Controlling a Build From the Command Line</title>
+    &command-line;
+  </chapter>
+
+  <chapter id="chap-install">
+    <title>Installing Files in Other Directories:  the &Install; Builder</title>
+    &install;
+  </chapter>
+
+  <chapter id="chap-factories">
+    <title>Platform-Independent File System Manipulation</title>
+    &factories;
+  </chapter>
+
+  <chapter id="chap-file-removal">
+    <title>Controlling Removal of Targets</title>
+    &file-removal;
+  </chapter>
+
+  <chapter id="chap-hierarchical">
+    <title>Hierarchical Builds</title>
+    &hierarchy;
+  </chapter>
+
+  <chapter id="chap-separate">
+    <title>Separating Source and Build Directories</title>
+    &separate;
+  </chapter>
+
+  <chapter id="chap-variants">
+    <title>Variant Builds</title>
+    &variants;
+  </chapter>
+
+  <!--
+
+  <chapter id="chap-builders-built-in">
+    <title>Built-In Builders</title>
+    &builders-built-in;
+  </chapter>
+
+  -->
+
+  <chapter id="chap-builders-writing">
+    <title>Writing Your Own Builders</title>
+    &builders-writing;
+  </chapter>
+
+  <chapter id="chap-builders-commands">
+    <title>Not Writing a Builder:  the &Command; Builder</title>
+    &builders-commands;
+  </chapter>
+
+  <chapter id="chap-add-method">
+    <title>Pseudo-Builders:  the AddMethod function</title>
+    &add-method;
+  </chapter>
+
+  <!--
+
+  XXX Action()
+  XXX AddPostAction()
+  XXX AddPreAction()
+
+  <chapter id="chap-actions">
+    <title>&SCons; Actions</title>
+    &actions;
+  </chapter>
+
+  -->
+
+  <chapter id="chap-scanners">
+    <title>Writing Scanners</title>
+    &scanners;
+  </chapter>
+
+  <chapter id="chap-repositories">
+    <title>Building From Code Repositories</title>
+    &repositories;
+  </chapter>
+
+  <chapter id="chap-sconf">
+    <title>Multi-Platform Configuration (&Autoconf; Functionality)</title>
+    &sconf;
+  </chapter>
+
+  <!--
+
+  <chapter id="chap-sourcecode">
+    <title>Fetching Files From Source Code Management Systems</title>
+    &sourcecode;
+  </chapter>
+
+  -->
+
+  <chapter id="chap-caching">
+    <title>Caching Built Files</title>
+    &caching;
+  </chapter>
+
+  <chapter id="chap-alias">
+    <title>Alias Targets</title>
+    &alias;
+  </chapter>
+
+  <chapter id="chap-java">
+    <title>Java Builds</title>
+    &java;
+  </chapter>
+
+  <!--
+
+  <chapter id="chap-run">
+    <title>How to Run &SCons;</title>
+    &run;
+  </chapter>
+
+  -->
+
+  <chapter id="chap-misc">
+    <title>Miscellaneous Functionality</title>
+    &misc;
+  </chapter>
+
+  <chapter id="chap-troubleshooting">
+    <title>Troubleshooting</title>
+    &troubleshoot;
+  </chapter>
+
+  <appendix id="app-variables">
+    <title>Construction Variables</title>
+    &variables-xml;
+  </appendix>
+
+  <appendix id="app-builders">
+    <title>Builders</title>
+    &builders;
+  </appendix>
+
+  <appendix id="app-tools">
+    <title>Tools</title>
+    &tools;
+  </appendix>
+
+  <appendix id="app-tasks">
+    <title>Handling Common Tasks</title>
+    &tasks;
+  </appendix>
+
+  <!--
+
+  <appendix id="app-python">
+    <title>Python Overview</title>
+    &example;
+  </appendix>
+
+  <appendix id="app-example">
+    <title>Complex &SCons; Example</title>
+    &example;
+  </appendix>
+
+  <appendix id="app-make">
+    <title>Converting From Make</title>
+    &make;
+  </appendix>
+
+  <appendix id="app-cons">
+    <title>Converting From Cons</title>
+    &cons;
+  </appendix>
+
+  <appendix id="app-ant">
+    <title>Converting From Ant</title>
+    &ant;
+  </appendix>
+
+  -->
+
+</book>
diff --git a/doc/user/make.in b/doc/user/make.in
new file mode 100644
index 0000000..e778c61
--- /dev/null
+++ b/doc/user/make.in
@@ -0,0 +1,121 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 Why Cons? Why not Make?
+
+Cons is a B<make> replacement. In the following paragraphs, we look at a few
+of the undesirable characteristics of make, and typical build environments
+based on make, that motivated the development of Cons.
+
+=head2 Build complexity
+
+Traditional make-based systems of any size tend to become quite complex. The
+original make utility and its derivatives have contributed to this tendency
+in a number of ways. Make is not good at dealing with systems that are
+spread over multiple directories. Various work-arounds are used to overcome
+this difficulty; the usual choice is for make to invoke itself recursively
+for each sub-directory of a build. This leads to complicated code, in which
+it is often unclear how a variable is set, or what effect the setting of a
+variable will have on the build as a whole. The make scripting language has
+gradually been extended to provide more possibilities, but these have
+largely served to clutter an already overextended language. Often, builds
+are done in multiple passes in order to provide appropriate products from
+one directory to another directory. This represents a further increase in
+build complexity.
+
+
+=head2 Build reproducibility
+
+The bane of all makes has always been the correct handling of
+dependencies. Most often, an attempt is made to do a reasonable job of
+dependencies within a single directory, but no serious attempt is made to do
+the job between directories. Even when dependencies are working correctly,
+make's reliance on a simple time stamp comparison to determine whether a
+file is out of date with respect to its dependents is not, in general,
+adequate for determining when a file should be rederived. If an external
+library, for example, is rebuilt and then ``snapped'' into place, the
+timestamps on its newly created files may well be earlier than the last
+local build, since it was built before it became visible.
+
+
+=head2 Variant builds
+
+Make provides only limited facilities for handling variant builds. With the
+proliferation of hardware platforms and the need for debuggable
+vs. optimized code, the ability to easily create these variants is
+essential. More importantly, if variants are created, it is important to
+either be able to separate the variants or to be able to reproduce the
+original or variant at will. With make it is very difficult to separate the
+builds into multiple build directories, separate from the source. And if
+this technique isn't used, it's also virtually impossible to guarantee at
+any given time which variant is present in the tree, without resorting to a
+complete rebuild.
+
+
+=head2 Repositories
+
+Make provides only limited support for building software from code that
+exists in a central repository directory structure.  The VPATH feature of
+GNU make (and some other make implementations) is intended to provide this,
+but doesn't work as expected: it changes the path of target file to the
+VPATH name too early in its analysis, and therefore searches for all
+dependencies in the VPATH directory.  To ensure correct development builds,
+it is important to be able to create a file in a local build directory and
+have any files in a code repository (a VPATH directory, in make terms) that
+depend on the local file get rebuilt properly.  This isn't possible with
+VPATH, without coding a lot of complex repository knowledge directly into
+the makefiles.
+
+-->
+
+ <para>
+
+   XXX
+
+ </para>
+
+ <section>
+ <title>Differences Between &Make; and &SCons;</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+ </section>
+
+ <section>
+ <title>Advantages of &SCons; Over &Make;</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+ </section>
diff --git a/doc/user/make.xml b/doc/user/make.xml
new file mode 100644
index 0000000..e778c61
--- /dev/null
+++ b/doc/user/make.xml
@@ -0,0 +1,121 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 Why Cons? Why not Make?
+
+Cons is a B<make> replacement. In the following paragraphs, we look at a few
+of the undesirable characteristics of make, and typical build environments
+based on make, that motivated the development of Cons.
+
+=head2 Build complexity
+
+Traditional make-based systems of any size tend to become quite complex. The
+original make utility and its derivatives have contributed to this tendency
+in a number of ways. Make is not good at dealing with systems that are
+spread over multiple directories. Various work-arounds are used to overcome
+this difficulty; the usual choice is for make to invoke itself recursively
+for each sub-directory of a build. This leads to complicated code, in which
+it is often unclear how a variable is set, or what effect the setting of a
+variable will have on the build as a whole. The make scripting language has
+gradually been extended to provide more possibilities, but these have
+largely served to clutter an already overextended language. Often, builds
+are done in multiple passes in order to provide appropriate products from
+one directory to another directory. This represents a further increase in
+build complexity.
+
+
+=head2 Build reproducibility
+
+The bane of all makes has always been the correct handling of
+dependencies. Most often, an attempt is made to do a reasonable job of
+dependencies within a single directory, but no serious attempt is made to do
+the job between directories. Even when dependencies are working correctly,
+make's reliance on a simple time stamp comparison to determine whether a
+file is out of date with respect to its dependents is not, in general,
+adequate for determining when a file should be rederived. If an external
+library, for example, is rebuilt and then ``snapped'' into place, the
+timestamps on its newly created files may well be earlier than the last
+local build, since it was built before it became visible.
+
+
+=head2 Variant builds
+
+Make provides only limited facilities for handling variant builds. With the
+proliferation of hardware platforms and the need for debuggable
+vs. optimized code, the ability to easily create these variants is
+essential. More importantly, if variants are created, it is important to
+either be able to separate the variants or to be able to reproduce the
+original or variant at will. With make it is very difficult to separate the
+builds into multiple build directories, separate from the source. And if
+this technique isn't used, it's also virtually impossible to guarantee at
+any given time which variant is present in the tree, without resorting to a
+complete rebuild.
+
+
+=head2 Repositories
+
+Make provides only limited support for building software from code that
+exists in a central repository directory structure.  The VPATH feature of
+GNU make (and some other make implementations) is intended to provide this,
+but doesn't work as expected: it changes the path of target file to the
+VPATH name too early in its analysis, and therefore searches for all
+dependencies in the VPATH directory.  To ensure correct development builds,
+it is important to be able to create a file in a local build directory and
+have any files in a code repository (a VPATH directory, in make terms) that
+depend on the local file get rebuilt properly.  This isn't possible with
+VPATH, without coding a lot of complex repository knowledge directly into
+the makefiles.
+
+-->
+
+ <para>
+
+   XXX
+
+ </para>
+
+ <section>
+ <title>Differences Between &Make; and &SCons;</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+ </section>
+
+ <section>
+ <title>Advantages of &SCons; Over &Make;</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+ </section>
diff --git a/doc/user/mergeflags.in b/doc/user/mergeflags.in
new file mode 100644
index 0000000..b50992b
--- /dev/null
+++ b/doc/user/mergeflags.in
@@ -0,0 +1,137 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+ &SCons; construction environments have a &MergeFlags; method
+ that merges a dictionary of values into the construction environment.
+ &MergeFlags; treats each value in the dictionary
+ as a list of options such as one might pass to a command
+ (such as a compiler or linker).
+ &MergeFlags; will not duplicate an option
+ if it already exists in the construction environment variable.
+
+ </para>
+
+ <para>
+
+ &MergeFlags; tries to be intelligent about merging options.
+ When merging options to any variable
+ whose name ends in <varname>PATH</varname>,
+ &MergeFlags; keeps the leftmost occurrence of the option,
+ because in typical lists of directory paths,
+ the first occurrence "wins."
+ When merging options to any other variable name,
+ &MergeFlags; keeps the rightmost occurrence of the option,
+ because in a list of typical command-line options,
+ the last occurrence "wins."
+
+ </para>
+
+ <scons_example name="MergeFlags1">
+   <file name="SConstruct" printme="1">
+    env = Environment()
+    env.Append(CCFLAGS = '-option -O3 -O1')
+    flags = { 'CCFLAGS' : '-whatever -O3' }
+    env.MergeFlags(flags)
+    print env['CCFLAGS']
+   </file>
+ </scons_example>
+
+ <scons_output example="MergeFlags1">
+    <scons_output_command>scons -Q</scons_output_command>
+ </scons_output>
+
+ <para>
+
+ Note that the default value for &cv-link-CCFLAGS;
+ <!--
+ [TODO: for when we make CLVar public]
+ is a <varname>CLVar</varname>,
+ -->
+ is an internal &SCons; object
+ which automatically converts
+ the options we specified as a string into a list.
+
+ </para>
+
+ <scons_example name="MergeFlags2">
+   <file name="SConstruct" printme="1">
+    env = Environment()
+    env.Append(CPPPATH = ['/include', '/usr/local/include', '/usr/include'])
+    flags = { 'CPPPATH' : ['/usr/opt/include', '/usr/local/include'] }
+    env.MergeFlags(flags)
+    print env['CPPPATH']
+   </file>
+ </scons_example>
+
+ <scons_output example="MergeFlags2">
+    <scons_output_command>scons -Q</scons_output_command>
+ </scons_output>
+
+ <para>
+
+ Note that the default value for &cv-link-CPPPATH;
+ <!--
+ [TODO: for when we make CLVar public]
+ is a Python list, not a <varname>CLVar</varname>,
+ -->
+ is a normal Python list,
+ so we must specify its values as a list
+ in the dictionary we pass to the &MergeFlags; function.
+
+ </para>
+
+ <para>
+
+ If &MergeFlags; is passed anything other than a dictionary,
+ it calls the &ParseFlags; method to convert it into a dictionary.
+
+ </para>
+
+ <scons_example name="MergeFlags3">
+   <file name="SConstruct" printme="1">
+    env = Environment()
+    env.Append(CCFLAGS = '-option -O3 -O1')
+    env.Append(CPPPATH = ['/include', '/usr/local/include', '/usr/include'])
+    env.MergeFlags('-whatever -I/usr/opt/include -O3 -I/usr/local/include')
+    print env['CCFLAGS']
+    print env['CPPPATH']
+   </file>
+ </scons_example>
+
+ <scons_output example="MergeFlags3">
+    <scons_output_command>scons -Q</scons_output_command>
+ </scons_output>
+
+ <para>
+
+ In the combined example above,
+ &ParseFlags; has sorted the options into their corresponding variables
+ and returned a dictionary for &MergeFlags; to apply
+ to the construction variables
+ in the specified construction environment.
+
+ </para>
diff --git a/doc/user/mergeflags.xml b/doc/user/mergeflags.xml
new file mode 100644
index 0000000..7edc986
--- /dev/null
+++ b/doc/user/mergeflags.xml
@@ -0,0 +1,138 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+ &SCons; construction environments have a &MergeFlags; method
+ that merges a dictionary of values into the construction environment.
+ &MergeFlags; treats each value in the dictionary
+ as a list of options such as one might pass to a command
+ (such as a compiler or linker).
+ &MergeFlags; will not duplicate an option
+ if it already exists in the construction environment variable.
+
+ </para>
+
+ <para>
+
+ &MergeFlags; tries to be intelligent about merging options.
+ When merging options to any variable
+ whose name ends in <varname>PATH</varname>,
+ &MergeFlags; keeps the leftmost occurrence of the option,
+ because in typical lists of directory paths,
+ the first occurrence "wins."
+ When merging options to any other variable name,
+ &MergeFlags; keeps the rightmost occurrence of the option,
+ because in a list of typical command-line options,
+ the last occurrence "wins."
+
+ </para>
+
+ <programlisting>
+    env = Environment()
+    env.Append(CCFLAGS = '-option -O3 -O1')
+    flags = { 'CCFLAGS' : '-whatever -O3' }
+    env.MergeFlags(flags)
+    print env['CCFLAGS']
+ </programlisting>
+
+ <screen>
+    % <userinput>scons -Q</userinput>
+    ['-option', '-O1', '-whatever', '-O3']
+    scons: `.' is up to date.
+ </screen>
+
+ <para>
+
+ Note that the default value for &cv-link-CCFLAGS;
+ <!--
+ [TODO: for when we make CLVar public]
+ is a <varname>CLVar</varname>,
+ -->
+ is an internal &SCons; object
+ which automatically converts
+ the options we specified as a string into a list.
+
+ </para>
+
+ <programlisting>
+    env = Environment()
+    env.Append(CPPPATH = ['/include', '/usr/local/include', '/usr/include'])
+    flags = { 'CPPPATH' : ['/usr/opt/include', '/usr/local/include'] }
+    env.MergeFlags(flags)
+    print env['CPPPATH']
+ </programlisting>
+
+ <screen>
+    % <userinput>scons -Q</userinput>
+    ['/include', '/usr/local/include', '/usr/include', '/usr/opt/include']
+    scons: `.' is up to date.
+ </screen>
+
+ <para>
+
+ Note that the default value for &cv-link-CPPPATH;
+ <!--
+ [TODO: for when we make CLVar public]
+ is a Python list, not a <varname>CLVar</varname>,
+ -->
+ is a normal Python list,
+ so we must specify its values as a list
+ in the dictionary we pass to the &MergeFlags; function.
+
+ </para>
+
+ <para>
+
+ If &MergeFlags; is passed anything other than a dictionary,
+ it calls the &ParseFlags; method to convert it into a dictionary.
+
+ </para>
+
+ <programlisting>
+    env = Environment()
+    env.Append(CCFLAGS = '-option -O3 -O1')
+    env.Append(CPPPATH = ['/include', '/usr/local/include', '/usr/include'])
+    env.MergeFlags('-whatever -I/usr/opt/include -O3 -I/usr/local/include')
+    print env['CCFLAGS']
+    print env['CPPPATH']
+ </programlisting>
+
+ <screen>
+    % <userinput>scons -Q</userinput>
+    ['-option', '-O1', '-whatever', '-O3']
+    ['/include', '/usr/local/include', '/usr/include', '/usr/opt/include']
+    scons: `.' is up to date.
+ </screen>
+
+ <para>
+
+ In the combined example above,
+ &ParseFlags; has sorted the options into their corresponding variables
+ and returned a dictionary for &MergeFlags; to apply
+ to the construction variables
+ in the specified construction environment.
+
+ </para>
diff --git a/doc/user/misc.in b/doc/user/misc.in
new file mode 100644
index 0000000..6679134
--- /dev/null
+++ b/doc/user/misc.in
@@ -0,0 +1,606 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  &SCons; supports a lot of additional functionality
+  that doesn't readily fit into the other chapters.
+
+  </para>
+
+  <section>
+  <title>Verifying the Python Version:  the &EnsurePythonVersion; Function</title>
+
+    <para>
+
+    Although the &SCons; code itself will run 
+    on any Python version 1.5.2 or later,
+    you are perfectly free to make use of
+    Python syntax and modules from more modern versions
+    (for example, Python 2.4 or 2.5)
+    when writing your &SConscript; files
+    or your own local modules.
+    If you do this, it's usually helpful to
+    configure &SCons; to exit gracefully with an error message
+    if it's being run with a version of Python
+    that simply won't work with your code.
+    This is especially true if you're going to use &SCons;
+    to build source code that you plan to distribute publicly,
+    where you can't be sure of the Python version
+    that an anonymous remote user might use
+    to try to build your software.
+
+    </para>
+
+    <para>
+
+    &SCons; provides an &EnsurePythonVersion; function for this.
+    You simply pass it the major and minor versions
+    numbers of the version of Python you require:
+
+    </para>
+
+    <!--
+
+    TODO:  Figure out how to generate the error message
+    regardless of executing Python version by faking out
+    the infrastructure in some way.
+
+    <scons_example name="EnsurePythonVersion">
+      <file name="SConstruct" printme="1">
+      EnsurePythonVersion(2, 5)
+      </file>
+    </scons_example>
+
+    -->
+
+    <sconstruct>
+      EnsurePythonVersion(2, 5)
+    </sconstruct>
+
+    <para>
+
+    And then &SCons will exit with the following error
+    message when a user runs it with an unsupported
+    earlier version of Python:
+
+    </para>
+
+    <!--
+
+    TODO:  Figure out how to generate the error message
+    regardless of executing Python version by faking out
+    the infrastructure in some way.
+
+    <scons_output example="EnsurePythonVersion">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      Python 2.5 or greater required, but you have Python 2.3.6
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Verifying the SCons Version:  the &EnsureSConsVersion; Function</title>
+
+    <para>
+
+    You may, of course, write your &SConscript; files
+    to use features that were only added in
+    recent versions of &SCons;.
+    When you publicly distribute software that is built using &SCons;,
+    it's helpful to have &SCons;
+    verify the version being used and
+    exit gracefully with an error message
+    if the user's version of &SCons; won't work
+    with your &SConscript; files.
+    &SCons; provides an &EnsureSConsVersion; function
+    that verifies the version of &SCons;
+    in the same
+    the &EnsurePythonVersion; function
+    verifies the version of Python,
+    by passing in the major and minor versions
+    numbers of the version of SCons you require:
+
+    </para>
+
+    <!--
+
+    TODO:  Figure out how to generate the error message
+    regardless of executing SCons version by faking out
+    the infrastructure in some way.
+
+    <scons_example name="EnsureSConsVersion">
+      <file name="SConstruct" printme="1">
+      EnsureSConsVersion(1, 0)
+      </file>
+    </scons_example>
+
+    -->
+
+    <sconstruct>
+      EnsureSConsVersion(1, 0)
+    </sconstruct>
+
+    <para>
+
+    And then &SCons will exit with the following error
+    message when a user runs it with an unsupported
+    earlier version of &SCons;:
+
+    </para>
+
+    <!--
+
+    TODO:  Figure out how to generate the error message
+    regardless of executing SCons version by faking out
+    the infrastructure in some way.
+
+    <scons_output example="EnsureSConsVersion">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      SCons 1.0 or greater required, but you have SCons 0.98.5
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Explicitly Terminating &SCons; While Reading &SConscript; Files:  the &Exit; Function</title>
+
+    <para>
+
+    &SCons; supports an &Exit; function
+    which can be used to terminate &SCons;
+    while reading the &SConscript; files,
+    usually because you've detected a condition
+    under which it doesn't make sense to proceed:
+
+    </para>
+
+    <scons_example name="Exit">
+      <file name="SConstruct" printme="1">
+      if ARGUMENTS.get('FUTURE'):
+          print "The FUTURE option is not supported yet!"
+          Exit(2)
+      env = Environment()
+      env.Program('hello.c')
+      </file>
+      <file name="hello.c">
+      hello.c
+      </file>
+    </scons_example>
+
+    <scons_output example="Exit">
+      <scons_output_command>scons -Q FUTURE=1</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The &Exit; function takes as an argument
+    the (numeric) exit status that you want &SCons; to exit with.
+    If you don't specify a value,
+    the default is to exit with <literal>0</literal>,
+    which indicates successful execution.
+
+    </para>
+
+    <para>
+
+    Note that the &Exit; function
+    is equivalent to calling the Python
+    <function>sys.exit</function> function
+    (which the it actually calls),
+    but because &Exit; is a &SCons; function,
+    you don't have to import the Python
+    <literal>sys</literal> module to use it.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Searching for Files:  the &FindFile; Function</title>
+
+    <para>
+
+     The &FindFile; function searches for a file in a list of directories.
+     If there is only one directory, it can be given as a simple string.
+     The function returns a File node if a matching file exists,
+     or None if no file is found.
+     (See the documentation for the &Glob; function for an alternative way
+     of searching for entries in a directory.)
+
+    </para>
+
+    <scons_example name="FindFile1a">
+      <file name="SConstruct" printme="1">
+       # one directory
+       print FindFile('missing', '.')
+       t = FindFile('exists', '.')
+       print t.__class__, t
+      </file>
+      <file name="exists">
+        exists
+      </file>
+    </scons_example>
+
+    <scons_output example="FindFile1a" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <scons_example name="FindFile1b">
+      <file name="SConstruct" printme="1">
+       # several directories
+       includes = [ '.', 'include', 'src/include']
+       headers = [ 'nonesuch.h', 'config.h', 'private.h', 'dist.h']
+       for hdr in headers:
+           print '%-12s' % ('%s:' % hdr), FindFile(hdr, includes)
+      </file>
+      <file name="config.h">
+        exists
+      </file>
+      <directory name="src"></directory>
+      <directory name="src/include"></directory>
+      </file>
+      <file name="src/include/private.h">
+        exists
+      <directory name="include"></directory>
+      </file>
+      <file name="include/dist.h">
+        exists
+    </scons_example>
+
+    <scons_output example="FindFile1b" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+   <!-- The man page says this should work, but it fails.
+    <para>
+
+     If the 'file' parameter is a list of files,
+     a list of File nodes is returned.
+
+    </para>
+
+    <scons_example name="FindFile1c">
+      <file name="SConstruct" printme="1">
+       # several directories
+       includes = [ '.', 'include', 'src/include']
+       headers = [ 'nonesuch.h', 'config.h', 'private.h', 'dist.h']
+       print FindFile(headers, includes)
+      </file>
+      <file name="config.h">
+        exists
+      </file>
+      <directory name="src"></directory>
+      <directory name="src/include"></directory>
+      </file>
+      <file name="src/include/private.h">
+        exists
+      <directory name="include"></directory>
+      </file>
+      <file name="include/dist.h">
+        exists
+    </scons_example>
+
+    <scons_output example="FindFile1c" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+   -->
+
+    <para>
+
+     If the file exists in more than one directory,
+     only the first occurrence is returned.
+
+    </para>
+
+    <scons_example name="FindFile1d">
+      <file name="SConstruct" printme="1">
+        print FindFile('multiple', ['sub1', 'sub2', 'sub3'])
+        print FindFile('multiple', ['sub2', 'sub3', 'sub1'])
+        print FindFile('multiple', ['sub3', 'sub1', 'sub2'])
+      </file>
+      <directory name="sub1"></directory>
+      <file name="sub1/multiple">
+        exists
+      </file>
+      <directory name="sub2"></directory>
+      <file name="sub2/multiple">
+        exists
+      </file>
+      <directory name="sub3"></directory>
+      <file name="sub3/multiple">
+        exists
+      </file>
+    </scons_example>
+
+    <scons_output example="FindFile1d" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+   <!-- file may be a list of file names or a single file name. -->
+
+    <para>
+
+    In addition to existing files, &FindFile; will also find derived files
+    (that is, non-leaf files) that haven't been built yet.
+    (Leaf files should already exist, or the build will fail!)
+
+    </para>
+
+    <scons_example name="FindFile2">
+      <file name="SConstruct" printme="1">
+       # Neither file exists, so build will fail
+       Command('derived', 'leaf', 'cat >$TARGET $SOURCE')
+       print FindFile('leaf', '.')
+       print FindFile('derived', '.')
+      </file>
+    </scons_example>
+
+    <scons_output example="FindFile2" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <scons_example name="FindFile2">
+      <file name="SConstruct" printme="1">
+       # Only 'leaf' exists
+       Command('derived', 'leaf', 'cat >$TARGET $SOURCE')
+       print FindFile('leaf', '.')
+       print FindFile('derived', '.')
+      </file>
+      <file name="leaf">
+       leaf
+      </file>
+    </scons_example>
+
+    <scons_output example="FindFile2" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    If a source file exists, &FindFile; will correctly return the name
+    in the build directory.
+
+    </para>
+
+    <scons_example name="FindFile3">
+      <file name="SConstruct" printme="1">
+       # Only 'src/leaf' exists
+       VariantDir('build', 'src')
+       print FindFile('leaf', 'build')
+      </file>
+      <directory name="src"></directory>
+      <file name="src/leaf">
+       leaf
+      </file>
+    </scons_example>
+
+    <scons_output example="FindFile3" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Handling Nested Lists:  the &Flatten; Function</title>
+
+    <para>
+
+    &SCons; supports a &Flatten; function
+    which takes an input Python sequence
+    (list or tuple)
+    and returns a flattened list
+    containing just the individual elements of
+    the sequence.
+    This can be handy when trying to examine
+    a list composed of the lists
+    returned by calls to various Builders.
+    For example, you might collect
+    object files built in different ways
+    into one call to the &Program; Builder
+    by just enclosing them in a list, as follows:
+
+    </para>
+
+    <scons_example name="Flatten1">
+      <file name="SConstruct" printme="1">
+      objects = [
+          Object('prog1.c'),
+          Object('prog2.c', CCFLAGS='-DFOO'),
+      ]
+      Program(objects)
+      </file>
+      <file name="prog1.c">
+      prog1.c
+      </file>
+      <file name="prog2.c">
+      prog2.c
+      </file>
+    </scons_example>
+
+    <para>
+
+    Because the Builder calls in &SCons;
+    flatten their input lists,
+    this works just fine to build the program:
+
+    </para>
+
+    <scons_output example="Flatten1">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    But if you were debugging your build
+    and wanted to print the absolute path
+    of each object file in the
+    <varname>objects</varname> list,
+    you might try the following simple approach,
+    trying to print each Node's
+    <literal>abspath</literal>
+    attribute:
+
+    </para>
+
+    <scons_example name="Flatten2">
+      <file name="SConstruct" printme="1">
+      objects = [
+          Object('prog1.c'),
+          Object('prog2.c', CCFLAGS='-DFOO'),
+      ]
+      Program(objects)
+
+      for object_file in objects:
+          print object_file.abspath
+      </file>
+      <file name="prog1.c">
+      prog1.c
+      </file>
+      <file name="prog2.c">
+      prog2.c
+      </file>
+    </scons_example>
+
+    <para>
+
+    This does not work as expected
+    because each call to <function>str</function>
+    is operating an embedded list returned by
+    each &Object; call,
+    not on the underlying Nodes within those lists:
+
+    </para>
+
+    <scons_output example="Flatten2">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The solution is to use the &Flatten; function
+    so that you can pass each Node to
+    the <function>str</function> separately:
+
+    </para>
+
+    <scons_example name="Flatten3">
+      <file name="SConstruct" printme="1">
+      objects = [
+          Object('prog1.c'),
+          Object('prog2.c', CCFLAGS='-DFOO'),
+      ]
+      Program(objects)
+
+      for object_file in Flatten(objects):
+          print object_file.abspath
+      </file>
+      <file name="prog1.c">
+      prog1.c
+      </file>
+      <file name="prog2.c">
+      prog2.c
+      </file>
+    </scons_example>
+
+    <!--
+
+    TODO:  can't use this now because it displays the temporary path name
+
+    <scons_output example="Flatten3">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      /home/me/project/prog1.o
+      /home/me/project/prog2.o
+      cc -o prog1.o -c prog1.c
+      cc -o prog2.o -c -DFOO prog2.c
+      cc -o prog1 prog1.o prog2.o
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Finding the Invocation Directory:  the &GetLaunchDir; Function</title>
+
+    <para>
+
+    If you need to find the directory from
+    which the user invoked the &scons; command,
+    you can use the &GetLaunchDir; function:
+
+    </para>
+
+    <sconstruct>
+      env = Environment(
+          LAUNCHDIR = GetLaunchDir(),
+      )
+      env.Command('directory_build_info',
+                  '$LAUNCHDIR/build_info'
+                  Copy('$TARGET', '$SOURCE'))
+    </sconstruct>
+
+    <para>
+
+    Because &SCons; is usually invoked from the top-level
+    directory in which the &SConstruct; file lives,
+    the Python <function>os.getcwd()</function>
+    is often equivalent.
+    However, the &SCons;
+    <literal>-u</literal>,
+    <literal>-U</literal>
+    and
+    <literal>-D</literal>
+    command-line options,
+    when invoked from a subdirectory,
+    will cause &SCons; to change to the directory
+    in which the &SConstruct; file is found.
+    When those options are used,
+    &GetLaunchDir; will still return the path to the
+    user's invoking subdirectory,
+    allowing the &SConscript; configuration
+    to still get at configuration (or other) files
+    from the originating directory.
+
+    </para>
+
+  </section>
diff --git a/doc/user/misc.xml b/doc/user/misc.xml
new file mode 100644
index 0000000..a2305ee
--- /dev/null
+++ b/doc/user/misc.xml
@@ -0,0 +1,565 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  &SCons; supports a lot of additional functionality
+  that doesn't readily fit into the other chapters.
+
+  </para>
+
+  <section>
+  <title>Verifying the Python Version:  the &EnsurePythonVersion; Function</title>
+
+    <para>
+
+    Although the &SCons; code itself will run 
+    on any Python version 1.5.2 or later,
+    you are perfectly free to make use of
+    Python syntax and modules from more modern versions
+    (for example, Python 2.4 or 2.5)
+    when writing your &SConscript; files
+    or your own local modules.
+    If you do this, it's usually helpful to
+    configure &SCons; to exit gracefully with an error message
+    if it's being run with a version of Python
+    that simply won't work with your code.
+    This is especially true if you're going to use &SCons;
+    to build source code that you plan to distribute publicly,
+    where you can't be sure of the Python version
+    that an anonymous remote user might use
+    to try to build your software.
+
+    </para>
+
+    <para>
+
+    &SCons; provides an &EnsurePythonVersion; function for this.
+    You simply pass it the major and minor versions
+    numbers of the version of Python you require:
+
+    </para>
+
+    <!--
+
+    TODO:  Figure out how to generate the error message
+    regardless of executing Python version by faking out
+    the infrastructure in some way.
+
+    <scons_example name="EnsurePythonVersion">
+      <file name="SConstruct" printme="1">
+      EnsurePythonVersion(2, 5)
+      </file>
+    </scons_example>
+
+    -->
+
+    <programlisting>
+      EnsurePythonVersion(2, 5)
+    </programlisting>
+
+    <para>
+
+    And then &SCons; will exit with the following error
+    message when a user runs it with an unsupported
+    earlier version of Python:
+
+    </para>
+
+    <!--
+
+    TODO:  Figure out how to generate the error message
+    regardless of executing Python version by faking out
+    the infrastructure in some way.
+
+    <scons_output example="EnsurePythonVersion">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      Python 2.5 or greater required, but you have Python 2.3.6
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Verifying the SCons Version:  the &EnsureSConsVersion; Function</title>
+
+    <para>
+
+    You may, of course, write your &SConscript; files
+    to use features that were only added in
+    recent versions of &SCons;.
+    When you publicly distribute software that is built using &SCons;,
+    it's helpful to have &SCons;
+    verify the version being used and
+    exit gracefully with an error message
+    if the user's version of &SCons; won't work
+    with your &SConscript; files.
+    &SCons; provides an &EnsureSConsVersion; function
+    that verifies the version of &SCons;
+    in the same
+    the &EnsurePythonVersion; function
+    verifies the version of Python,
+    by passing in the major and minor versions
+    numbers of the version of SCons you require:
+
+    </para>
+
+    <!--
+
+    TODO:  Figure out how to generate the error message
+    regardless of executing SCons version by faking out
+    the infrastructure in some way.
+
+    <scons_example name="EnsureSConsVersion">
+      <file name="SConstruct" printme="1">
+      EnsureSConsVersion(1, 0)
+      </file>
+    </scons_example>
+
+    -->
+
+    <programlisting>
+      EnsureSConsVersion(1, 0)
+    </programlisting>
+
+    <para>
+
+    And then &SCons; will exit with the following error
+    message when a user runs it with an unsupported
+    earlier version of &SCons;:
+
+    </para>
+
+    <!--
+
+    TODO:  Figure out how to generate the error message
+    regardless of executing SCons version by faking out
+    the infrastructure in some way.
+
+    <scons_output example="EnsureSConsVersion">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      SCons 1.0 or greater required, but you have SCons 0.98.5
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Explicitly Terminating &SCons; While Reading &SConscript; Files:  the &Exit; Function</title>
+
+    <para>
+
+    &SCons; supports an &Exit; function
+    which can be used to terminate &SCons;
+    while reading the &SConscript; files,
+    usually because you've detected a condition
+    under which it doesn't make sense to proceed:
+
+    </para>
+
+    <programlisting>
+      if ARGUMENTS.get('FUTURE'):
+          print "The FUTURE option is not supported yet!"
+          Exit(2)
+      env = Environment()
+      env.Program('hello.c')
+    </programlisting>
+
+    <screen>
+      % <userinput>scons -Q FUTURE=1</userinput>
+      The FUTURE option is not supported yet!
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+    </screen>
+
+    <para>
+
+    The &Exit; function takes as an argument
+    the (numeric) exit status that you want &SCons; to exit with.
+    If you don't specify a value,
+    the default is to exit with <literal>0</literal>,
+    which indicates successful execution.
+
+    </para>
+
+    <para>
+
+    Note that the &Exit; function
+    is equivalent to calling the Python
+    <function>sys.exit</function> function
+    (which the it actually calls),
+    but because &Exit; is a &SCons; function,
+    you don't have to import the Python
+    <literal>sys</literal> module to use it.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Searching for Files:  the &FindFile; Function</title>
+
+    <para>
+
+     The &FindFile; function searches for a file in a list of directories.
+     If there is only one directory, it can be given as a simple string.
+     The function returns a File node if a matching file exists,
+     or None if no file is found.
+     (See the documentation for the &Glob; function for an alternative way
+     of searching for entries in a directory.)
+
+    </para>
+
+    <programlisting>
+       # one directory
+       print FindFile('missing', '.')
+       t = FindFile('exists', '.')
+       print t.__class__, t
+    </programlisting>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       None
+       SCons.Node.FS.File exists
+       scons: `.' is up to date.
+    </screen>
+
+    <programlisting>
+       # several directories
+       includes = [ '.', 'include', 'src/include']
+       headers = [ 'nonesuch.h', 'config.h', 'private.h', 'dist.h']
+       for hdr in headers:
+           print '%-12s' % ('%s:' % hdr), FindFile(hdr, includes)
+</programlisting>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       nonesuch.h:  None
+       config.h:    config.h
+       private.h:   src/include/private.h
+       dist.h:      include/dist.h
+       scons: `.' is up to date.
+    </screen>
+
+   <!-- The man page says this should work, but it fails.
+    <para>
+
+     If the 'file' parameter is a list of files,
+     a list of File nodes is returned.
+
+    </para>
+
+    <scons_example name="FindFile1c">
+      <file name="SConstruct" printme="1">
+       # several directories
+       includes = [ '.', 'include', 'src/include']
+       headers = [ 'nonesuch.h', 'config.h', 'private.h', 'dist.h']
+       print FindFile(headers, includes)
+      </file>
+      <file name="config.h">
+        exists
+      </file>
+      <directory name="src"></directory>
+      <directory name="src/include"></directory>
+      </file>
+      <file name="src/include/private.h">
+        exists
+      <directory name="include"></directory>
+      </file>
+      <file name="include/dist.h">
+        exists
+    </scons_example>
+
+    <scons_output example="FindFile1c" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+   -->
+
+    <para>
+
+     If the file exists in more than one directory,
+     only the first occurrence is returned.
+
+    </para>
+
+    <programlisting>
+        print FindFile('multiple', ['sub1', 'sub2', 'sub3'])
+        print FindFile('multiple', ['sub2', 'sub3', 'sub1'])
+        print FindFile('multiple', ['sub3', 'sub1', 'sub2'])
+    </programlisting>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       sub1/multiple
+       sub2/multiple
+       sub3/multiple
+       scons: `.' is up to date.
+    </screen>
+
+   <!-- file may be a list of file names or a single file name. -->
+
+    <para>
+
+    In addition to existing files, &FindFile; will also find derived files
+    (that is, non-leaf files) that haven't been built yet.
+    (Leaf files should already exist, or the build will fail!)
+
+    </para>
+
+    <programlisting>
+       # Neither file exists, so build will fail
+       Command('derived', 'leaf', 'cat &gt;$TARGET $SOURCE')
+       print FindFile('leaf', '.')
+       print FindFile('derived', '.')
+    </programlisting>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       None
+       derived
+       scons: *** [derived] Source `leaf' not found, needed by target `derived'.
+    </screen>
+
+    <programlisting>
+       # Neither file exists, so build will fail
+       Command('derived', 'leaf', 'cat &gt;$TARGET $SOURCE')
+       print FindFile('leaf', '.')
+       print FindFile('derived', '.')
+
+       # Only 'leaf' exists
+       Command('derived', 'leaf', 'cat &gt;$TARGET $SOURCE')
+       print FindFile('leaf', '.')
+       print FindFile('derived', '.')
+    </programlisting>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       leaf
+       derived
+       cat &gt; derived leaf
+    </screen>
+
+    <para>
+
+    If a source file exists, &FindFile; will correctly return the name
+    in the build directory.
+
+    </para>
+
+    <programlisting>
+       # Only 'src/leaf' exists
+       VariantDir('build', 'src')
+       print FindFile('leaf', 'build')
+    </programlisting>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       build/leaf
+       scons: `.' is up to date.
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Handling Nested Lists:  the &Flatten; Function</title>
+
+    <para>
+
+    &SCons; supports a &Flatten; function
+    which takes an input Python sequence
+    (list or tuple)
+    and returns a flattened list
+    containing just the individual elements of
+    the sequence.
+    This can be handy when trying to examine
+    a list composed of the lists
+    returned by calls to various Builders.
+    For example, you might collect
+    object files built in different ways
+    into one call to the &Program; Builder
+    by just enclosing them in a list, as follows:
+
+    </para>
+
+    <programlisting>
+      objects = [
+          Object('prog1.c'),
+          Object('prog2.c', CCFLAGS='-DFOO'),
+      ]
+      Program(objects)
+    </programlisting>
+
+    <para>
+
+    Because the Builder calls in &SCons;
+    flatten their input lists,
+    this works just fine to build the program:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o prog1.o -c prog1.c
+      cc -o prog2.o -c -DFOO prog2.c
+      cc -o prog1 prog1.o prog2.o
+    </screen>
+
+    <para>
+
+    But if you were debugging your build
+    and wanted to print the absolute path
+    of each object file in the
+    <varname>objects</varname> list,
+    you might try the following simple approach,
+    trying to print each Node's
+    <literal>abspath</literal>
+    attribute:
+
+    </para>
+
+    <programlisting>
+      objects = [
+          Object('prog1.c'),
+          Object('prog2.c', CCFLAGS='-DFOO'),
+      ]
+      Program(objects)
+
+      for object_file in objects:
+          print object_file.abspath
+    </programlisting>
+
+    <para>
+
+    This does not work as expected
+    because each call to <function>str</function>
+    is operating an embedded list returned by
+    each &Object; call,
+    not on the underlying Nodes within those lists:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      AttributeError: NodeList instance has no attribute 'abspath':
+        File "/home/my/project/SConstruct", line 8:
+          print object_file.abspath
+    </screen>
+
+    <para>
+
+    The solution is to use the &Flatten; function
+    so that you can pass each Node to
+    the <function>str</function> separately:
+
+    </para>
+
+    <programlisting>
+      objects = [
+          Object('prog1.c'),
+          Object('prog2.c', CCFLAGS='-DFOO'),
+      ]
+      Program(objects)
+
+      for object_file in Flatten(objects):
+          print object_file.abspath
+    </programlisting>
+
+    <!--
+
+    TODO:  can't use this now because it displays the temporary path name
+
+    <scons_output example="Flatten3">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      /home/me/project/prog1.o
+      /home/me/project/prog2.o
+      cc -o prog1.o -c prog1.c
+      cc -o prog2.o -c -DFOO prog2.c
+      cc -o prog1 prog1.o prog2.o
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Finding the Invocation Directory:  the &GetLaunchDir; Function</title>
+
+    <para>
+
+    If you need to find the directory from
+    which the user invoked the &scons; command,
+    you can use the &GetLaunchDir; function:
+
+    </para>
+
+    <programlisting>
+      env = Environment(
+          LAUNCHDIR = GetLaunchDir(),
+      )
+      env.Command('directory_build_info',
+                  '$LAUNCHDIR/build_info'
+                  Copy('$TARGET', '$SOURCE'))
+    </programlisting>
+
+    <para>
+
+    Because &SCons; is usually invoked from the top-level
+    directory in which the &SConstruct; file lives,
+    the Python <function>os.getcwd()</function>
+    is often equivalent.
+    However, the &SCons;
+    <literal>-u</literal>,
+    <literal>-U</literal>
+    and
+    <literal>-D</literal>
+    command-line options,
+    when invoked from a subdirectory,
+    will cause &SCons; to change to the directory
+    in which the &SConstruct; file is found.
+    When those options are used,
+    &GetLaunchDir; will still return the path to the
+    user's invoking subdirectory,
+    allowing the &SConscript; configuration
+    to still get at configuration (or other) files
+    from the originating directory.
+
+    </para>
+
+  </section>
diff --git a/doc/user/nodes.in b/doc/user/nodes.in
new file mode 100644
index 0000000..c914ce5
--- /dev/null
+++ b/doc/user/nodes.in
@@ -0,0 +1,386 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  Internally, &SCons; represents all of the files
+  and directories it knows about as &Nodes;.
+  These internal objects
+  (not object <emphasis>files</emphasis>)
+  can be used in a variety of ways
+  to make your &SConscript;
+  files portable and easy to read.
+
+  </para>
+
+  <section>
+  <title>Builder Methods Return Lists of Target Nodes</title>
+
+    <para>
+
+    All builder methods return a list of
+    &Node; objects that identify the
+    target file or files that will be built.
+    These returned &Nodes; can be passed
+    as arguments to other builder methods.
+
+    </para>
+
+    <para>
+
+    For example, suppose that we want to build
+    the two object files that make up a program with different options.
+    This would mean calling the &b-link-Object;
+    builder once for each object file,
+    specifying the desired options:
+
+    </para>
+
+    <sconstruct>
+    Object('hello.c', CCFLAGS='-DHELLO')
+    Object('goodbye.c', CCFLAGS='-DGOODBYE')
+    </sconstruct>
+
+    <para>
+
+    One way to combine these object files
+    into the resulting program
+    would be to call the &b-link-Program;
+    builder with the names of the object files
+    listed as sources:
+
+    </para>
+
+    <sconstruct>
+    Object('hello.c', CCFLAGS='-DHELLO')
+    Object('goodbye.c', CCFLAGS='-DGOODBYE')
+    Program(['hello.o', 'goodbye.o'])
+    </sconstruct>
+
+    <para>
+
+    The problem with specifying the names as strings
+    is that our &SConstruct; file is no longer portable
+    across operating systems.
+    It won't, for example, work on Windows
+    because the object files there would be
+    named &hello_obj; and &goodbye_obj;,
+    not &hello_o; and &goodbye_o;.
+
+    </para>
+
+    <para>
+
+    A better solution is to assign the lists of targets
+    returned by the calls to the &b-Object; builder to variables,
+    which we can then concatenate in our
+    call to the &b-Program; builder:
+
+    </para>
+
+    <scons_example name="ex1">
+      <file name="SConstruct" printme="1">
+      hello_list = Object('hello.c', CCFLAGS='-DHELLO')
+      goodbye_list = Object('goodbye.c', CCFLAGS='-DGOODBYE')
+      Program(hello_list + goodbye_list)
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+      <file name="goodbye.c">
+      int main() { printf("Goodbye, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    This makes our &SConstruct; file portable again,
+    the build output on Linux looking like:
+
+    </para>
+
+    <scons_output example="ex1" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    And on Windows:
+
+    </para>
+
+    <scons_output example="ex1" os="win32">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    We'll see examples of using the list of nodes
+    returned by builder methods throughout
+    the rest of this guide.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Explicitly Creating File and Directory Nodes</title>
+
+    <para>
+
+    It's worth mentioning here that
+    &SCons; maintains a clear distinction
+    between Nodes that represent files
+    and Nodes that represent directories.
+    &SCons; supports &File; and &Dir;
+    functions that, respectively,
+    return a file or directory Node:
+
+    </para>
+
+    <scons_example name="print">
+      <file name="SConstruct" printme="1">
+      hello_c = File('hello.c')
+      Program(hello_c)
+
+      classes = Dir('classes')
+      Java(classes, 'src')
+      </file>
+    </scons_example>
+
+    <para>
+
+    Normally, you don't need to call
+    &File; or &Dir; directly,
+    because calling a builder method automatically
+    treats strings as the names of files or directories,
+    and translates them into
+    the Node objects for you.
+    The &File; and &Dir; functions can come in handy
+    in situations where you need to explicitly
+    instruct &SCons; about the type of Node being
+    passed to a builder or other function,
+    or unambiguously refer to a specific
+    file in a directory tree.
+    <!--
+    (For an example of when you might
+    need to use &File; or &Dir; to
+    prevent ambiguous interpretation of a string
+    naming a file or directory, see
+    <xref linkend="chap-hierarchy">.)
+    -->
+
+    </para>
+
+    <para>
+
+    There are also times when you may need to
+    refer to an entry in a file system
+    without knowing in advance
+    whether it's a file or a directory.
+    For those situations,
+    &SCons; also supports an &Entry; function,
+    which returns a Node
+    that can represent either a file or a directory.
+
+    </para>
+
+    <sconstruct>
+    xyzzy = Entry('xyzzy')
+    </sconstruct>
+
+    <para>
+
+    The returned <literal>xyzzy</literal> Node
+    will be turned into a file or directory Node
+    the first time it is used by a builder method
+    or other function that
+    requires one vs. the other.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Printing &Node; File Names</title>
+
+    <para>
+
+    One of the most common things you can do
+    with a Node is use it to print the
+    file name that the node represents.
+    Keep in mind, though, that because the object
+    returned by a builder call
+    is a <emphasis>list</emphasis> of Nodes,
+    you must use Python subscripts
+    to fetch individual Nodes from the list.
+    For example, the following &SConstruct; file:
+
+    </para>
+
+    <scons_example name="print">
+      <file name="SConstruct" printme="1">
+      object_list = Object('hello.c')
+      program_list = Program(object_list)
+      print "The object file is:", object_list[0]
+      print "The program file is:", program_list[0]
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Would print the following file names on a POSIX system:
+
+    </para>
+
+    <scons_output example="print" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    And the following file names on a Windows system:
+
+    </para>
+
+    <scons_output example="print" os="win32">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Note that in the above example,
+    the <literal>object_list[0]</literal>
+    extracts an actual Node <emphasis>object</emphasis>
+    from the list,
+    and the Python <literal>print</literal> statement
+    converts the object to a string for printing.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Using a &Node;'s File Name as a String</title>
+
+    <para>
+
+    Printing a &Node;'s name
+    as described in the previous section
+    works because the string representation of a &Node; object
+    is the name of the file.
+    If you want to do something other than
+    print the name of the file,
+    you can fetch it by using the builtin Python
+    &str; function.
+    For example, if you want to use the Python
+    <function>os.path.exists</function>
+    to figure out whether a file
+    exists while the &SConstruct; file
+    is being read and executed,
+    you can fetch the string as follows:
+
+    </para>
+
+    <scons_example name="exists">
+      <file name="SConstruct" printme="1">
+      import os.path
+      program_list = Program('hello.c')
+      program_name = str(program_list[0])
+      if not os.path.exists(program_name):
+          print program_name, "does not exist!"
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Which executes as follows on a POSIX system:
+
+    </para>
+
+    <scons_output example="exists" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Fetching the Contents of a &Node;</title>
+
+    <para>
+
+    XXX Describe using read() and readlines()
+    when we add that as a public interface.
+
+    </para>
+
+    <scons_example name="read">
+      <file name="SConstruct" printme="1">
+      hello_c = File('hello.c')
+      contents = hello_c.read()
+      print "contents are:"
+      print contents
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Which executes as follows on a POSIX system:
+
+    </para>
+
+    <scons_output example="read" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  -->
+
+  <!--
+
+  <section>
+  <title>Python Value &Node;</title>
+
+    <para>
+
+    XXX Value()
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/nodes.xml b/doc/user/nodes.xml
new file mode 100644
index 0000000..46215c4
--- /dev/null
+++ b/doc/user/nodes.xml
@@ -0,0 +1,401 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  Internally, &SCons; represents all of the files
+  and directories it knows about as &Nodes;.
+  These internal objects
+  (not object <emphasis>files</emphasis>)
+  can be used in a variety of ways
+  to make your &SConscript;
+  files portable and easy to read.
+
+  </para>
+
+  <section>
+  <title>Builder Methods Return Lists of Target Nodes</title>
+
+    <para>
+
+    All builder methods return a list of
+    &Node; objects that identify the
+    target file or files that will be built.
+    These returned &Nodes; can be passed
+    as arguments to other builder methods.
+
+    </para>
+
+    <para>
+
+    For example, suppose that we want to build
+    the two object files that make up a program with different options.
+    This would mean calling the &b-link-Object;
+    builder once for each object file,
+    specifying the desired options:
+
+    </para>
+
+    <programlisting>
+    Object('hello.c', CCFLAGS='-DHELLO')
+    Object('goodbye.c', CCFLAGS='-DGOODBYE')
+    </programlisting>
+
+    <para>
+
+    One way to combine these object files
+    into the resulting program
+    would be to call the &b-link-Program;
+    builder with the names of the object files
+    listed as sources:
+
+    </para>
+
+    <programlisting>
+    Object('hello.c', CCFLAGS='-DHELLO')
+    Object('goodbye.c', CCFLAGS='-DGOODBYE')
+    Program(['hello.o', 'goodbye.o'])
+    </programlisting>
+
+    <para>
+
+    The problem with specifying the names as strings
+    is that our &SConstruct; file is no longer portable
+    across operating systems.
+    It won't, for example, work on Windows
+    because the object files there would be
+    named &hello_obj; and &goodbye_obj;,
+    not &hello_o; and &goodbye_o;.
+
+    </para>
+
+    <para>
+
+    A better solution is to assign the lists of targets
+    returned by the calls to the &b-Object; builder to variables,
+    which we can then concatenate in our
+    call to the &b-Program; builder:
+
+    </para>
+
+    <programlisting>
+      hello_list = Object('hello.c', CCFLAGS='-DHELLO')
+      goodbye_list = Object('goodbye.c', CCFLAGS='-DGOODBYE')
+      Program(hello_list + goodbye_list)
+    </programlisting>
+
+    <para>
+
+    This makes our &SConstruct; file portable again,
+    the build output on Linux looking like:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       cc -o goodbye.o -c -DGOODBYE goodbye.c
+       cc -o hello.o -c -DHELLO hello.c
+       cc -o hello hello.o goodbye.o
+    </screen>
+
+    <para>
+
+    And on Windows:
+
+    </para>
+
+    <screen>
+       C:\><userinput>scons -Q</userinput>
+       
+       scons: warning: No installed VCs
+       File "&lt;stdin&gt;", line 67, in __call__
+       
+       scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+       File "&lt;stdin&gt;", line 67, in __call__
+       cl /Fogoodbye.obj /c goodbye.c -DGOODBYE
+       cl /Fohello.obj /c hello.c -DHELLO
+       link /nologo /OUT:hello.exe hello.obj goodbye.obj
+    </screen>
+
+    <para>
+
+    We'll see examples of using the list of nodes
+    returned by builder methods throughout
+    the rest of this guide.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Explicitly Creating File and Directory Nodes</title>
+
+    <para>
+
+    It's worth mentioning here that
+    &SCons; maintains a clear distinction
+    between Nodes that represent files
+    and Nodes that represent directories.
+    &SCons; supports &File; and &Dir;
+    functions that, respectively,
+    return a file or directory Node:
+
+    </para>
+
+    <programlisting>
+      hello_c = File('hello.c')
+      Program(hello_c)
+
+      classes = Dir('classes')
+      Java(classes, 'src')
+    </programlisting>
+
+    <para>
+
+    Normally, you don't need to call
+    &File; or &Dir; directly,
+    because calling a builder method automatically
+    treats strings as the names of files or directories,
+    and translates them into
+    the Node objects for you.
+    The &File; and &Dir; functions can come in handy
+    in situations where you need to explicitly
+    instruct &SCons; about the type of Node being
+    passed to a builder or other function,
+    or unambiguously refer to a specific
+    file in a directory tree.
+    <!--
+    (For an example of when you might
+    need to use &File; or &Dir; to
+    prevent ambiguous interpretation of a string
+    naming a file or directory, see
+    <xref linkend="chap-hierarchy">.)
+    -->
+
+    </para>
+
+    <para>
+
+    There are also times when you may need to
+    refer to an entry in a file system
+    without knowing in advance
+    whether it's a file or a directory.
+    For those situations,
+    &SCons; also supports an &Entry; function,
+    which returns a Node
+    that can represent either a file or a directory.
+
+    </para>
+
+    <programlisting>
+    xyzzy = Entry('xyzzy')
+    </programlisting>
+
+    <para>
+
+    The returned <literal>xyzzy</literal> Node
+    will be turned into a file or directory Node
+    the first time it is used by a builder method
+    or other function that
+    requires one vs. the other.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Printing &Node; File Names</title>
+
+    <para>
+
+    One of the most common things you can do
+    with a Node is use it to print the
+    file name that the node represents.
+    Keep in mind, though, that because the object
+    returned by a builder call
+    is a <emphasis>list</emphasis> of Nodes,
+    you must use Python subscripts
+    to fetch individual Nodes from the list.
+    For example, the following &SConstruct; file:
+
+    </para>
+
+    <programlisting>
+      hello_c = File('hello.c')
+      Program(hello_c)
+
+      classes = Dir('classes')
+      Java(classes, 'src')
+
+      object_list = Object('hello.c')
+      program_list = Program(object_list)
+      print "The object file is:", object_list[0]
+      print "The program file is:", program_list[0]
+    </programlisting>
+
+    <para>
+
+    Would print the following file names on a POSIX system:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      The object file is: hello.o
+      The program file is: hello
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+    </screen>
+
+    <para>
+
+    And the following file names on a Windows system:
+
+    </para>
+
+    <screen>
+      C:\><userinput>scons -Q</userinput>
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      The object file is: hello.obj
+      The program file is: hello.exe
+      cl /Fohello.obj /c hello.c /nologo
+      link /nologo /OUT:hello.exe hello.obj
+    </screen>
+
+    <para>
+
+    Note that in the above example,
+    the <literal>object_list[0]</literal>
+    extracts an actual Node <emphasis>object</emphasis>
+    from the list,
+    and the Python <literal>print</literal> statement
+    converts the object to a string for printing.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Using a &Node;'s File Name as a String</title>
+
+    <para>
+
+    Printing a &Node;'s name
+    as described in the previous section
+    works because the string representation of a &Node; object
+    is the name of the file.
+    If you want to do something other than
+    print the name of the file,
+    you can fetch it by using the builtin Python
+    &str; function.
+    For example, if you want to use the Python
+    <function>os.path.exists</function>
+    to figure out whether a file
+    exists while the &SConstruct; file
+    is being read and executed,
+    you can fetch the string as follows:
+
+    </para>
+
+    <programlisting>
+      import os.path
+      program_list = Program('hello.c')
+      program_name = str(program_list[0])
+      if not os.path.exists(program_name):
+          print program_name, "does not exist!"
+    </programlisting>
+
+    <para>
+
+    Which executes as follows on a POSIX system:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      hello does not exist!
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+    </screen>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Fetching the Contents of a &Node;</title>
+
+    <para>
+
+    XXX Describe using read() and readlines()
+    when we add that as a public interface.
+
+    </para>
+
+    <scons_example name="read">
+      <file name="SConstruct" printme="1">
+      hello_c = File('hello.c')
+      contents = hello_c.read()
+      print "contents are:"
+      print contents
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Which executes as follows on a POSIX system:
+
+    </para>
+
+    <scons_output example="read" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  -->
+
+  <!--
+
+  <section>
+  <title>Python Value &Node;</title>
+
+    <para>
+
+    XXX Value()
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/output.in b/doc/user/output.in
new file mode 100644
index 0000000..1f600f3
--- /dev/null
+++ b/doc/user/output.in
@@ -0,0 +1,681 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  A key aspect of creating a usable build configuration
+  is providing good output from the build
+  so its users can readily understand
+  what the build is doing
+  and get information about how to control the build.
+  &SCons; provides several ways of
+  controlling output from the build configuration
+  to help make the build
+  more useful and understandable.
+
+  </para>
+
+  <section>
+  <title>Providing Build Help:  the &Help; Function</title>
+
+    <para>
+
+    It's often very useful to be able to give
+    users some help that describes the
+    specific targets, build options, etc.,
+    that can be used for your build.
+    &SCons; provides the &Help; function
+    to allow you to specify this help text:
+
+    </para>
+
+    <scons_example name="ex1">
+       <file name="SConstruct" printme="1">
+       Help("""
+       Type: 'scons program' to build the production program,
+             'scons debug' to build the debug version.
+       """)
+       </file>
+    </scons_example>
+
+    <para>
+
+    (Note the above use of the Python triple-quote syntax,
+    which comes in very handy for
+    specifying multi-line strings like help text.)
+
+    </para>
+
+    <para>
+
+    When the &SConstruct; or &SConscript; files
+    contain such a call to the &Help; function,
+    the specified help text will be displayed in response to
+    the &SCons; <literal>-h</literal> option:
+
+    </para>
+
+    <scons_output example="ex1">
+       <scons_output_command>scons -h</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The &SConscript; files may contain
+    multiple calls to the &Help; function,
+    in which case the specified text(s)
+    will be concatenated when displayed.
+    This allows you to split up the
+    help text across multiple &SConscript; files.
+    In this situation, the order in
+    which the &SConscript; files are called
+    will determine the order in which the &Help; functions are called,
+    which will determine the order in which
+    the various bits of text will get concatenated.
+
+    </para>
+
+    <para>
+
+    Another use would be to make the help text conditional
+    on some variable.
+    For example, suppose you only want to display
+    a line about building a Windows-only
+    version of a program when actually
+    run on Windows.
+    The following &SConstruct; file:
+
+    </para>
+
+    <scons_example name="ex2">
+       <file name="SConstruct" printme="1">
+       env = Environment()
+
+       Help("\nType: 'scons program' to build the production program.\n")
+
+       if env['PLATFORM'] == 'win32':
+           Help("\nType: 'scons windebug' to build the Windows debug version.\n")
+       </file>
+    </scons_example>
+
+    <para>
+
+    Will display the complete help text on Windows:
+
+    </para>
+
+    <scons_output example="ex2" os="win32">
+       <scons_output_command>scons -h</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    But only show the relevant option on a Linux or UNIX system:
+
+    </para>
+
+    <scons_output example="ex2" os="posix">
+       <scons_output_command>scons -h</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    If there is no &Help; text in the &SConstruct; or
+    &SConscript; files,
+    &SCons; will revert to displaying its
+    standard list that describes the &SCons; command-line
+    options.
+    This list is also always displayed whenever
+    the <literal>-H</literal> option is used.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Controlling How &SCons; Prints Build Commands:  the <envar>$*COMSTR</envar> Variables</title>
+
+    <para>
+
+    Sometimes the commands executed
+    to compile object files or link programs
+    (or build other targets)
+    can get very long,
+    long enough to make it difficult for users
+    to distinguish error messages or
+    other important build output
+    from the commands themselves.
+    All of the default <envar>$*COM</envar> variables
+    that specify the command lines
+    used to build various types of target files
+    have a corresponding <envar>$*COMSTR</envar> variable
+    that can be set to an alternative
+    string that will be displayed
+    when the target is built.
+
+    </para>
+
+    <para>
+
+    For example, suppose you want to
+    have &SCons; display a
+    <literal>"Compiling"</literal>
+    message whenever it's compiling an object file,
+    and a
+    <literal>"Linking"</literal>
+    when it's linking an executable.
+    You could write a &SConstruct; file
+    that looks like:
+
+    </para>
+
+    <scons_example name="COMSTR">
+       <file name="SConstruct" printme="1">
+       env = Environment(CCCOMSTR = "Compiling $TARGET",
+                         LINKCOMSTR = "Linking $TARGET")
+       env.Program('foo.c')
+       </file>
+       <file name="foo.c">
+       foo.c
+       </file>
+    </scons_example>
+
+    <para>
+
+    Which would then yield the output:
+
+    </para>
+
+    <!--
+
+    <scons_output example="COMSTR" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       Compiling foo.o
+       Linking foo
+    </screen>
+
+    <para>
+
+    &SCons; performs complete variable substitution
+    on <envar>$*COMSTR</envar> variables,
+    so they have access to all of the
+    standard variables like &cv-TARGET; &cv-SOURCES;, etc.,
+    as well as any construction variables
+    that happen to be configured in
+    the construction environment
+    used to build a specific target.
+
+    </para>
+
+    <para>
+
+    Of course, sometimes it's still important to
+    be able to see the exact command
+    that &SCons; will execute to build a target.
+    For example, you may simply need to verify
+    that &SCons; is configured to supply
+    the right options to the compiler,
+    or a developer may want to
+    cut-and-paste a compile command
+    to add a few options
+    for a custom test.
+
+    </para>
+
+    <para>
+
+    One common way to give users
+    control over whether or not
+    &SCons; should print the actual command line
+    or a short, configured summary
+    is to add support for a
+    <varname>VERBOSE</varname>
+    command-line variable to your &SConstruct; file.
+    A simple configuration for this might look like:
+
+    </para>
+
+    <scons_example name="COMSTR-VERBOSE">
+       <file name="SConstruct" printme="1">
+       env = Environment()
+       if ARGUMENTS.get('VERBOSE') != "1':
+           env['CCCOMSTR'] = "Compiling $TARGET"
+           env['LINKCOMSTR'] = "Linking $TARGET"
+       env.Program('foo.c')
+       </file>
+       <file name="foo.c">
+       foo.c
+       </file>
+    </scons_example>
+
+    <para>
+
+
+    By only setting the appropriate
+    <envar>$*COMSTR</envar> variables
+    if the user specifies
+    <literal>VERBOSE=1</literal>
+    on the command line,
+    the user has control
+    over how &SCons;
+    displays these particular command lines:
+
+    </para>
+
+    <!--
+
+    <scons_output example="COMSTR-VERBOSE" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+       <scons_output_command>scons -Q -c</scons_output_command>
+       <scons_output_command>scons -Q VERBOSE=1</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       Compiling foo.o
+       Linking foo
+       % <userinput>scons -Q -c</userinput>
+       Removed foo.o
+       Removed foo
+       % <userinput>scons -Q VERBOSE=1</userinput>
+       cc -o foo.o -c foo.c
+       cc -o foo foo.o
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Providing Build Progress Output:  the &Progress; Function</title>
+
+    <para>
+
+    Another aspect of providing good build output
+    is to give the user feedback
+    about what &SCons; is doing
+    even when nothing is being built at the moment.
+    This can be especially true for large builds
+    when most of the targets are already up-to-date.
+    Because &SCons; can take a long time
+    making absolutely sure that every
+    target is, in fact, up-to-date
+    with respect to a lot of dependency files,
+    it can be easy for users to mistakenly
+    conclude that &SCons; is hung
+    or that there is some other problem with the build.
+
+    </para>
+
+    <para>
+
+    One way to deal with this perception
+    is to configure &SCons; to print something to
+    let the user know what it's "thinking about."
+    The &Progress; function
+    allows you to specify a string
+    that will be printed for every file
+    that &SCons; is "considering"
+    while it is traversing the dependency graph
+    to decide what targets are or are not up-to-date.
+
+    </para>
+
+    <scons_example name="Progress-TARGET">
+      <file name="SConstruct" printme="1">
+        Progress('Evaluating $TARGET\n')
+        Program('f1.c')
+        Program('f2.c')
+      </file>
+      <file name="f1.c">
+        f1.c
+      </file>
+      <file name="f2.c">
+        f2.c
+      </file>
+    </scons_example>
+
+    <para>
+
+    Note that the &Progress; function does not
+    arrange for a newline to be printed automatically
+    at the end of the string (as does the Python
+    <literal>print</literal> statement),
+    and we must specify the
+    <literal>\n</literal>
+    that we want printed at the end of the configured string.
+    This configuration, then,
+    will have &SCons;
+    print that it is <literal>Evaluating</literal>
+    each file that it encounters
+    in turn as it traverses the dependency graph:
+
+    </para>
+
+    <scons_output example="Progress-TARGET" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Of course, normally you don't want to add
+    all of these additional lines to your build output,
+    as that can make it difficult for the user
+    to find errors or other important messages.
+    A more useful way to display
+    this progress might be
+    to have the file names printed
+    directly to the user's screen,
+    not to the same standard output
+    stream where build output is printed,
+    and to use a carriage return character
+    (<literal>\r</literal>)
+    so that each file name gets re-printed on the same line.
+    Such a configuration would look like:
+
+    </para>
+
+    <sconstruct>
+        Progress('$TARGET\r',
+                 file=open('/dev/tty', 'w'),
+                 overwrite=True)
+        Program('f1.c')
+        Program('f2.c')
+    </sconstruct>
+
+    <para>
+
+    Note that we also specified the
+    <literal>overwrite=True</literal> argument
+    to the &Progress; function,
+    which causes &SCons; to
+    "wipe out" the previous string with space characters
+    before printing the next &Progress; string.
+    Without the
+    <literal>overwrite=True</literal> argument,
+    a shorter file name would not overwrite
+    all of the charactes in a longer file name that 
+    precedes it,
+    making it difficult to tell what the
+    actual file name is on the output.
+    Also note that we opened up the
+    <filename>/dev/tty</filename> file
+    for direct access (on POSIX) to
+    the user's screen.
+    On Windows, the equivalent would be to open
+    the <filename>con:</filename> file name.
+
+    </para>
+
+    <para>
+
+    Also, it's important to know that although you can use
+    <literal>$TARGET</literal> to substitute the name of
+    the node in the string,
+    the &Progress; function does <emphasis>not</emphasis>
+    perform general variable substitution
+    (because there's not necessarily a construction
+    environment involved in evaluating a node
+    like a source file, for example).
+
+    </para>
+
+    <para>
+
+    You can also specify a list of strings
+    to the &Progress; function,
+    in which case &SCons; will
+    display each string in turn.
+    This can be used to implement a "spinner"
+    by having &SCons; cycle through a
+    sequence of strings:
+
+    </para>
+
+    <sconstruct>
+        Progress(['-\r', '\\\r', '|\r', '/\r'], interval=5)
+        Program('f1.c')
+        Program('f2.c')
+    </sconstruct>
+
+    <para>
+
+    Note that here we have also used the
+    <literal>interval=</literal>
+    keyword argument to have &SCons;
+    only print a new "spinner" string
+    once every five evaluated nodes.
+    Using an <literal>interval=</literal> count,
+    even with strings that use <literal>$TARGET</literal> like
+    our examples above,
+    can be a good way to lessen the
+    work that &SCons; expends printing &Progress; strings,
+    while still giving the user feedback
+    that indicates &SCons; is still
+    working on evaluating the build.
+
+    </para>
+
+    <para>
+
+    Lastly, you can have direct control
+    over how to print each evaluated node
+    by passing a Python function
+    (or other Python callable)
+    to the &Progress function.
+    Your function will be called
+    for each evaluated node,
+    allowing you to
+    implement more sophisticated logic
+    like adding a counter:
+
+    </para>
+
+    <scons_example name="Progress-callable">
+      <file name="SConstruct" printme="1">
+        screen = open('/dev/tty', 'w')
+        count = 0
+        def progress_function(node)
+            count += 1
+            screen.write('Node %4d: %s\r' % (count, node))
+
+        Progress(progress_function)
+      </file>
+    </scons_example>
+
+    <para>
+
+    Of course, if you choose,
+    you could completely ignore the
+    <varname>node</varname> argument to the function,
+    and just print a count,
+    or anything else you wish.
+
+    </para>
+
+    <para>
+
+    (Note that there's an obvious follow-on question here:
+    how would you find the total number of nodes
+    that <emphasis>will be</emphasis>
+    evaluated so you can tell the user how
+    close the build is to finishing?
+    Unfortunately, in the general case,
+    there isn't a good way to do that,
+    short of having &SCons; evaluate its
+    dependency graph twice,
+    first to count the total and
+    the second time to actually build the targets.
+    This would be necessary because
+    you can't know in advance which
+    target(s) the user actually requested
+    to be built.
+    The entire build may consist of thousands of Nodes,
+    for example,
+    but maybe the user specifically requested
+    that only a single object file be built.)
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Printing Detailed Build Status:  the &GetBuildFailures; Function</title>
+
+    <para>
+
+    SCons, like most build tools, returns zero status to
+    the shell on success and nonzero status on failure.
+    Sometimes it's useful to give more information about
+    the build status at the end of the run, for instance
+    to print an informative message, send an email, or
+    page the poor slob who broke the build.
+
+    </para>
+
+    <para>
+
+    SCons provides a &GetBuildFailures; method that
+    you can use in a python <function>atexit</function> function
+    to get a list of objects describing the actions that failed
+    while attempting to build targets.  There can be more
+    than one if you're using <literal>-j</literal>.  Here's a 
+    simple example:
+
+    </para>
+
+    <scons_example name="gbf1">
+      <file name="SConstruct" printme="1">
+        import atexit
+
+        def print_build_failures():
+            from SCons.Script import GetBuildFailures
+            for bf in GetBuildFailures():
+                print "%s failed: %s" % (bf.node, bf.errstr)
+        atexit.register(print_build_failures)
+      </file>
+    </scons_example>
+
+    <para>
+
+    The <function>atexit.register</function> call
+    registers <function>print_build_failures</function>
+    as an <function>atexit</function> callback, to be called
+    before &SCons; exits.  When that function is called,
+    it calls &GetBuildFailures; to fetch the list of failed objects.
+    See the man page
+    for the detailed contents of the returned objects;
+    some of the more useful attributes are 
+    <literal>.node</literal>,
+    <literal>.errstr</literal>,
+    <literal>.filename</literal>, and
+    <literal>.command</literal>.
+    The <literal>filename</literal> is not necessarily
+    the same file as the <literal>node</literal>; the
+    <literal>node</literal> is the target that was
+    being built when the error occurred, while the 
+    <literal>filename</literal>is the file or dir that
+    actually caused the error.
+    Note:  only call &GetBuildFailures; at the end of the
+    build; calling it at any other time is undefined.
+
+    </para>
+
+    <para>   
+
+    Here is a more complete example showing how to
+    turn each element of &GetBuildFailures; into a string:
+
+    </para>
+
+    <scons_example name="gbf2">
+      <file name="SConstruct" printme="1">
+        # Make the build fail if we pass fail=1 on the command line
+        if ARGUMENTS.get('fail', 0):
+            Command('target', 'source', ['/bin/false'])
+
+        def bf_to_str(bf):
+            """Convert an element of GetBuildFailures() to a string
+            in a useful way."""
+            import SCons.Errors
+            if bf is None: # unknown targets product None in list
+                return '(unknown tgt)'
+            elif isinstance(bf, SCons.Errors.StopError):
+                return str(bf)
+            elif bf.node:
+                return str(bf.node) + ': ' + bf.errstr
+            elif bf.filename:
+                return bf.filename + ': ' + bf.errstr
+            return 'unknown failure: ' + bf.errstr
+        import atexit
+
+        def build_status():
+            """Convert the build status to a 2-tuple, (status, msg)."""
+            from SCons.Script import GetBuildFailures
+            bf = GetBuildFailures()
+            if bf:
+                # bf is normally a list of build failures; if an element is None,
+                # it's because of a target that scons doesn't know anything about.
+                status = 'failed'
+                failures_message = "\n".join(["Failed building %s" % bf_to_str(x)
+                                   for x in bf if x is not None])
+            else:
+                # if bf is None, the build completed successfully.
+                status = 'ok'
+                failures_message = ''
+            return (status, failures_message)
+
+        def display_build_status():
+            """Display the build status.  Called by atexit.
+            Here you could do all kinds of complicated things."""
+            status, failures_message = build_status()
+            if status == 'failed':
+               print "FAILED!!!!"  # could display alert, ring bell, etc.
+            elif status == 'ok':
+               print "Build succeeded."
+            print failures_message
+
+        atexit.register(display_build_status)
+      </file>
+    </scons_example>
+
+    <para>
+    
+    When this runs, you'll see the appropriate output:
+
+    </para>
+
+    <scons_output example="gbf2">
+          <scons_output_command>scons -Q</scons_output_command>
+          <scons_output_command>scons -Q fail=1</scons_output_command>
+    </scons_output>
+
+  </section>
diff --git a/doc/user/output.xml b/doc/user/output.xml
new file mode 100644
index 0000000..89b443b
--- /dev/null
+++ b/doc/user/output.xml
@@ -0,0 +1,703 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  A key aspect of creating a usable build configuration
+  is providing good output from the build
+  so its users can readily understand
+  what the build is doing
+  and get information about how to control the build.
+  &SCons; provides several ways of
+  controlling output from the build configuration
+  to help make the build
+  more useful and understandable.
+
+  </para>
+
+  <section>
+  <title>Providing Build Help:  the &Help; Function</title>
+
+    <para>
+
+    It's often very useful to be able to give
+    users some help that describes the
+    specific targets, build options, etc.,
+    that can be used for your build.
+    &SCons; provides the &Help; function
+    to allow you to specify this help text:
+
+    </para>
+
+    <programlisting>
+       Help("""
+       Type: 'scons program' to build the production program,
+             'scons debug' to build the debug version.
+       """)
+    </programlisting>
+
+    <para>
+
+    (Note the above use of the Python triple-quote syntax,
+    which comes in very handy for
+    specifying multi-line strings like help text.)
+
+    </para>
+
+    <para>
+
+    When the &SConstruct; or &SConscript; files
+    contain such a call to the &Help; function,
+    the specified help text will be displayed in response to
+    the &SCons; <literal>-h</literal> option:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -h</userinput>
+       scons: Reading SConscript files ...
+       scons: done reading SConscript files.
+       
+       Type: 'scons program' to build the production program,
+             'scons debug' to build the debug version.
+       
+       Use scons -H for help about command-line options.
+    </screen>
+
+    <para>
+
+    The &SConscript; files may contain
+    multiple calls to the &Help; function,
+    in which case the specified text(s)
+    will be concatenated when displayed.
+    This allows you to split up the
+    help text across multiple &SConscript; files.
+    In this situation, the order in
+    which the &SConscript; files are called
+    will determine the order in which the &Help; functions are called,
+    which will determine the order in which
+    the various bits of text will get concatenated.
+
+    </para>
+
+    <para>
+
+    Another use would be to make the help text conditional
+    on some variable.
+    For example, suppose you only want to display
+    a line about building a Windows-only
+    version of a program when actually
+    run on Windows.
+    The following &SConstruct; file:
+
+    </para>
+
+    <programlisting>
+       env = Environment()
+
+       Help("\nType: 'scons program' to build the production program.\n")
+
+       if env['PLATFORM'] == 'win32':
+           Help("\nType: 'scons windebug' to build the Windows debug version.\n")
+    </programlisting>
+
+    <para>
+
+    Will display the complete help text on Windows:
+
+    </para>
+
+    <screen>
+       C:\><userinput>scons -h</userinput>
+       scons: Reading SConscript files ...
+       
+       scons: warning: No installed VCs
+       File "&lt;stdin&gt;", line 67, in __call__
+       
+       scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+       File "&lt;stdin&gt;", line 67, in __call__
+       
+       scons: warning: No installed VCs
+       File "&lt;stdin&gt;", line 67, in __call__
+       
+       scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+       File "&lt;stdin&gt;", line 67, in __call__
+       scons: done reading SConscript files.
+       
+       Type: 'scons program' to build the production program.
+       
+       Type: 'scons windebug' to build the Windows debug version.
+       
+       Use scons -H for help about command-line options.
+    </screen>
+
+    <para>
+
+    But only show the relevant option on a Linux or UNIX system:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -h</userinput>
+       scons: Reading SConscript files ...
+       scons: done reading SConscript files.
+       
+       Type: 'scons program' to build the production program.
+       
+       Use scons -H for help about command-line options.
+    </screen>
+
+    <para>
+
+    If there is no &Help; text in the &SConstruct; or
+    &SConscript; files,
+    &SCons; will revert to displaying its
+    standard list that describes the &SCons; command-line
+    options.
+    This list is also always displayed whenever
+    the <literal>-H</literal> option is used.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Controlling How &SCons; Prints Build Commands:  the <envar>$*COMSTR</envar> Variables</title>
+
+    <para>
+
+    Sometimes the commands executed
+    to compile object files or link programs
+    (or build other targets)
+    can get very long,
+    long enough to make it difficult for users
+    to distinguish error messages or
+    other important build output
+    from the commands themselves.
+    All of the default <envar>$*COM</envar> variables
+    that specify the command lines
+    used to build various types of target files
+    have a corresponding <envar>$*COMSTR</envar> variable
+    that can be set to an alternative
+    string that will be displayed
+    when the target is built.
+
+    </para>
+
+    <para>
+
+    For example, suppose you want to
+    have &SCons; display a
+    <literal>"Compiling"</literal>
+    message whenever it's compiling an object file,
+    and a
+    <literal>"Linking"</literal>
+    when it's linking an executable.
+    You could write a &SConstruct; file
+    that looks like:
+
+    </para>
+
+    <programlisting>
+       env = Environment(CCCOMSTR = "Compiling $TARGET",
+                         LINKCOMSTR = "Linking $TARGET")
+       env.Program('foo.c')
+    </programlisting>
+
+    <para>
+
+    Which would then yield the output:
+
+    </para>
+
+    <!--
+
+    <scons_output example="COMSTR" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       Compiling foo.o
+       Linking foo
+    </screen>
+
+    <para>
+
+    &SCons; performs complete variable substitution
+    on <envar>$*COMSTR</envar> variables,
+    so they have access to all of the
+    standard variables like &cv-TARGET; &cv-SOURCES;, etc.,
+    as well as any construction variables
+    that happen to be configured in
+    the construction environment
+    used to build a specific target.
+
+    </para>
+
+    <para>
+
+    Of course, sometimes it's still important to
+    be able to see the exact command
+    that &SCons; will execute to build a target.
+    For example, you may simply need to verify
+    that &SCons; is configured to supply
+    the right options to the compiler,
+    or a developer may want to
+    cut-and-paste a compile command
+    to add a few options
+    for a custom test.
+
+    </para>
+
+    <para>
+
+    One common way to give users
+    control over whether or not
+    &SCons; should print the actual command line
+    or a short, configured summary
+    is to add support for a
+    <varname>VERBOSE</varname>
+    command-line variable to your &SConstruct; file.
+    A simple configuration for this might look like:
+
+    </para>
+
+    <programlisting>
+       env = Environment()
+       if ARGUMENTS.get('VERBOSE') != "1':
+           env['CCCOMSTR'] = "Compiling $TARGET"
+           env['LINKCOMSTR'] = "Linking $TARGET"
+       env.Program('foo.c')
+    </programlisting>
+
+    <para>
+
+
+    By only setting the appropriate
+    <envar>$*COMSTR</envar> variables
+    if the user specifies
+    <literal>VERBOSE=1</literal>
+    on the command line,
+    the user has control
+    over how &SCons;
+    displays these particular command lines:
+
+    </para>
+
+    <!--
+
+    <scons_output example="COMSTR-VERBOSE" os="posix">
+       <scons_output_command>scons -Q</scons_output_command>
+       <scons_output_command>scons -Q -c</scons_output_command>
+       <scons_output_command>scons -Q VERBOSE=1</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       Compiling foo.o
+       Linking foo
+       % <userinput>scons -Q -c</userinput>
+       Removed foo.o
+       Removed foo
+       % <userinput>scons -Q VERBOSE=1</userinput>
+       cc -o foo.o -c foo.c
+       cc -o foo foo.o
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Providing Build Progress Output:  the &Progress; Function</title>
+
+    <para>
+
+    Another aspect of providing good build output
+    is to give the user feedback
+    about what &SCons; is doing
+    even when nothing is being built at the moment.
+    This can be especially true for large builds
+    when most of the targets are already up-to-date.
+    Because &SCons; can take a long time
+    making absolutely sure that every
+    target is, in fact, up-to-date
+    with respect to a lot of dependency files,
+    it can be easy for users to mistakenly
+    conclude that &SCons; is hung
+    or that there is some other problem with the build.
+
+    </para>
+
+    <para>
+
+    One way to deal with this perception
+    is to configure &SCons; to print something to
+    let the user know what it's "thinking about."
+    The &Progress; function
+    allows you to specify a string
+    that will be printed for every file
+    that &SCons; is "considering"
+    while it is traversing the dependency graph
+    to decide what targets are or are not up-to-date.
+
+    </para>
+
+    <programlisting>
+        Progress('Evaluating $TARGET\n')
+        Program('f1.c')
+        Program('f2.c')
+    </programlisting>
+
+    <para>
+
+    Note that the &Progress; function does not
+    arrange for a newline to be printed automatically
+    at the end of the string (as does the Python
+    <literal>print</literal> statement),
+    and we must specify the
+    <literal>\n</literal>
+    that we want printed at the end of the configured string.
+    This configuration, then,
+    will have &SCons;
+    print that it is <literal>Evaluating</literal>
+    each file that it encounters
+    in turn as it traverses the dependency graph:
+
+    </para>
+
+    <screen>
+       % <userinput>scons -Q</userinput>
+       Evaluating SConstruct
+       Evaluating f1.c
+       Evaluating f1.o
+       cc -o f1.o -c f1.c
+       Evaluating f1
+       cc -o f1 f1.o
+       Evaluating f2.c
+       Evaluating f2.o
+       cc -o f2.o -c f2.c
+       Evaluating f2
+       cc -o f2 f2.o
+       Evaluating .
+    </screen>
+
+    <para>
+
+    Of course, normally you don't want to add
+    all of these additional lines to your build output,
+    as that can make it difficult for the user
+    to find errors or other important messages.
+    A more useful way to display
+    this progress might be
+    to have the file names printed
+    directly to the user's screen,
+    not to the same standard output
+    stream where build output is printed,
+    and to use a carriage return character
+    (<literal>\r</literal>)
+    so that each file name gets re-printed on the same line.
+    Such a configuration would look like:
+
+    </para>
+
+    <programlisting>
+        Progress('$TARGET\r',
+                 file=open('/dev/tty', 'w'),
+                 overwrite=True)
+        Program('f1.c')
+        Program('f2.c')
+    </programlisting>
+
+    <para>
+
+    Note that we also specified the
+    <literal>overwrite=True</literal> argument
+    to the &Progress; function,
+    which causes &SCons; to
+    "wipe out" the previous string with space characters
+    before printing the next &Progress; string.
+    Without the
+    <literal>overwrite=True</literal> argument,
+    a shorter file name would not overwrite
+    all of the charactes in a longer file name that 
+    precedes it,
+    making it difficult to tell what the
+    actual file name is on the output.
+    Also note that we opened up the
+    <filename>/dev/tty</filename> file
+    for direct access (on POSIX) to
+    the user's screen.
+    On Windows, the equivalent would be to open
+    the <filename>con:</filename> file name.
+
+    </para>
+
+    <para>
+
+    Also, it's important to know that although you can use
+    <literal>$TARGET</literal> to substitute the name of
+    the node in the string,
+    the &Progress; function does <emphasis>not</emphasis>
+    perform general variable substitution
+    (because there's not necessarily a construction
+    environment involved in evaluating a node
+    like a source file, for example).
+
+    </para>
+
+    <para>
+
+    You can also specify a list of strings
+    to the &Progress; function,
+    in which case &SCons; will
+    display each string in turn.
+    This can be used to implement a "spinner"
+    by having &SCons; cycle through a
+    sequence of strings:
+
+    </para>
+
+    <programlisting>
+        Progress(['-\r', '\\\r', '|\r', '/\r'], interval=5)
+        Program('f1.c')
+        Program('f2.c')
+    </programlisting>
+
+    <para>
+
+    Note that here we have also used the
+    <literal>interval=</literal>
+    keyword argument to have &SCons;
+    only print a new "spinner" string
+    once every five evaluated nodes.
+    Using an <literal>interval=</literal> count,
+    even with strings that use <literal>$TARGET</literal> like
+    our examples above,
+    can be a good way to lessen the
+    work that &SCons; expends printing &Progress; strings,
+    while still giving the user feedback
+    that indicates &SCons; is still
+    working on evaluating the build.
+
+    </para>
+
+    <para>
+
+    Lastly, you can have direct control
+    over how to print each evaluated node
+    by passing a Python function
+    (or other Python callable)
+    to the &Progress; function.
+    Your function will be called
+    for each evaluated node,
+    allowing you to
+    implement more sophisticated logic
+    like adding a counter:
+
+    </para>
+
+    <programlisting>
+        screen = open('/dev/tty', 'w')
+        count = 0
+        def progress_function(node)
+            count += 1
+            screen.write('Node %4d: %s\r' % (count, node))
+
+        Progress(progress_function)
+    </programlisting>
+
+    <para>
+
+    Of course, if you choose,
+    you could completely ignore the
+    <varname>node</varname> argument to the function,
+    and just print a count,
+    or anything else you wish.
+
+    </para>
+
+    <para>
+
+    (Note that there's an obvious follow-on question here:
+    how would you find the total number of nodes
+    that <emphasis>will be</emphasis>
+    evaluated so you can tell the user how
+    close the build is to finishing?
+    Unfortunately, in the general case,
+    there isn't a good way to do that,
+    short of having &SCons; evaluate its
+    dependency graph twice,
+    first to count the total and
+    the second time to actually build the targets.
+    This would be necessary because
+    you can't know in advance which
+    target(s) the user actually requested
+    to be built.
+    The entire build may consist of thousands of Nodes,
+    for example,
+    but maybe the user specifically requested
+    that only a single object file be built.)
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Printing Detailed Build Status:  the &GetBuildFailures; Function</title>
+
+    <para>
+
+    SCons, like most build tools, returns zero status to
+    the shell on success and nonzero status on failure.
+    Sometimes it's useful to give more information about
+    the build status at the end of the run, for instance
+    to print an informative message, send an email, or
+    page the poor slob who broke the build.
+
+    </para>
+
+    <para>
+
+    SCons provides a &GetBuildFailures; method that
+    you can use in a python <function>atexit</function> function
+    to get a list of objects describing the actions that failed
+    while attempting to build targets.  There can be more
+    than one if you're using <literal>-j</literal>.  Here's a 
+    simple example:
+
+    </para>
+
+    <programlisting>
+        import atexit
+
+        def print_build_failures():
+            from SCons.Script import GetBuildFailures
+            for bf in GetBuildFailures():
+                print "%s failed: %s" % (bf.node, bf.errstr)
+        atexit.register(print_build_failures)
+    </programlisting>
+
+    <para>
+
+    The <function>atexit.register</function> call
+    registers <function>print_build_failures</function>
+    as an <function>atexit</function> callback, to be called
+    before &SCons; exits.  When that function is called,
+    it calls &GetBuildFailures; to fetch the list of failed objects.
+    See the man page
+    for the detailed contents of the returned objects;
+    some of the more useful attributes are 
+    <literal>.node</literal>,
+    <literal>.errstr</literal>,
+    <literal>.filename</literal>, and
+    <literal>.command</literal>.
+    The <literal>filename</literal> is not necessarily
+    the same file as the <literal>node</literal>; the
+    <literal>node</literal> is the target that was
+    being built when the error occurred, while the 
+    <literal>filename</literal>is the file or dir that
+    actually caused the error.
+    Note:  only call &GetBuildFailures; at the end of the
+    build; calling it at any other time is undefined.
+
+    </para>
+
+    <para>   
+
+    Here is a more complete example showing how to
+    turn each element of &GetBuildFailures; into a string:
+
+    </para>
+
+    <programlisting>
+        # Make the build fail if we pass fail=1 on the command line
+        if ARGUMENTS.get('fail', 0):
+            Command('target', 'source', ['/bin/false'])
+
+        def bf_to_str(bf):
+            """Convert an element of GetBuildFailures() to a string
+            in a useful way."""
+            import SCons.Errors
+            if bf is None: # unknown targets product None in list
+                return '(unknown tgt)'
+            elif isinstance(bf, SCons.Errors.StopError):
+                return str(bf)
+            elif bf.node:
+                return str(bf.node) + ': ' + bf.errstr
+            elif bf.filename:
+                return bf.filename + ': ' + bf.errstr
+            return 'unknown failure: ' + bf.errstr
+        import atexit
+
+        def build_status():
+            """Convert the build status to a 2-tuple, (status, msg)."""
+            from SCons.Script import GetBuildFailures
+            bf = GetBuildFailures()
+            if bf:
+                # bf is normally a list of build failures; if an element is None,
+                # it's because of a target that scons doesn't know anything about.
+                status = 'failed'
+                failures_message = "\n".join(["Failed building %s" % bf_to_str(x)
+                                   for x in bf if x is not None])
+            else:
+                # if bf is None, the build completed successfully.
+                status = 'ok'
+                failures_message = ''
+            return (status, failures_message)
+
+        def display_build_status():
+            """Display the build status.  Called by atexit.
+            Here you could do all kinds of complicated things."""
+            status, failures_message = build_status()
+            if status == 'failed':
+               print "FAILED!!!!"  # could display alert, ring bell, etc.
+            elif status == 'ok':
+               print "Build succeeded."
+            print failures_message
+
+        atexit.register(display_build_status)
+    </programlisting>
+
+    <para>
+    
+    When this runs, you'll see the appropriate output:
+
+    </para>
+
+    <screen>
+          % <userinput>scons -Q</userinput>
+          scons: `.' is up to date.
+          Build succeeded.
+          % <userinput>scons -Q fail=1</userinput>
+          scons: *** [target] Source `source' not found, needed by target `target'.
+          FAILED!!!!
+          Failed building target: Source `source' not found, needed by target `target'.
+    </screen>
+
+  </section>
diff --git a/doc/user/parseconfig.in b/doc/user/parseconfig.in
new file mode 100644
index 0000000..db97c35
--- /dev/null
+++ b/doc/user/parseconfig.in
@@ -0,0 +1,114 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+ Configuring the right options to build programs to work with
+ libraries--especially shared libraries--that are available
+ on POSIX systems can be very complicated.
+ To help this situation,
+ various utilies with names that end in <filename>config</filename>
+ return the command-line options for the GNU Compiler Collection (GCC)
+ that are needed to use these libraries;
+ for example, the command-line options
+ to use a library named <filename>lib</filename>
+ would be found by calling a utility named <filename>lib-config</filename>.
+
+ </para>
+
+ <para>
+
+ A more recent convention is that these options
+ are available from the generic <filename>pkg-config</filename> program,
+ which has common framework, error handling, and the like,
+ so that all the package creator has to do is provide the set of strings
+ for his particular package.
+
+ </para>
+
+ <para>
+
+ &SCons; construction environments have a &ParseConfig; method
+ that executes a <filename>*config</filename> utility
+ (either <filename>pkg-config</filename> or a
+ more specific utility)
+ and configures the appropriate construction variables
+ in the environment
+ based on the command-line options
+ returned by the specified command.
+
+ </para>
+
+ <scons_example name="ParseConfig1">
+   <file name="SConstruct" printme="1">
+    env = Environment()
+    env['CPPPATH'] = ['/lib/compat']
+    env.ParseConfig("pkg-config x11 --cflags --libs")
+    print env['CPPPATH']
+   </file>
+ </scons_example>
+
+ <para>
+
+ &SCons; will execute the specified command string,
+ parse the resultant flags,
+ and add the flags to the appropriate environment variables.
+
+ </para>
+
+ <scons_output example="ParseConfig1">
+    <scons_output_command>scons -Q</scons_output_command>
+ </scons_output>
+
+ <para>
+
+ In the example above, &SCons; has added the include directory to
+ <varname>CPPPATH</varname>.
+ (Depending upon what other flags are emitted by the
+ <filename>pkg-config</filename> command,
+ other variables may have been extended as well.)
+
+ </para>
+
+ <para>
+
+ Note that the options are merged with existing options using
+ the &MergeFlags; method,
+ so that each option only occurs once in the construction variable:
+
+ </para>
+
+ <scons_example name="ParseConfig2">
+   <file name="SConstruct" printme="1">
+    env = Environment()
+    env.ParseConfig("pkg-config x11 --cflags --libs")
+    env.ParseConfig("pkg-config x11 --cflags --libs")
+    print env['CPPPATH']
+   </file>
+ </scons_example>
+
+ <scons_output example="ParseConfig2">
+    <scons_output_command>scons -Q</scons_output_command>
+ </scons_output>
diff --git a/doc/user/parseconfig.xml b/doc/user/parseconfig.xml
new file mode 100644
index 0000000..1f85ad0
--- /dev/null
+++ b/doc/user/parseconfig.xml
@@ -0,0 +1,132 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+ Configuring the right options to build programs to work with
+ libraries--especially shared libraries--that are available
+ on POSIX systems can be very complicated.
+ To help this situation,
+ various utilies with names that end in <filename>config</filename>
+ return the command-line options for the GNU Compiler Collection (GCC)
+ that are needed to use these libraries;
+ for example, the command-line options
+ to use a library named <filename>lib</filename>
+ would be found by calling a utility named <filename>lib-config</filename>.
+
+ </para>
+
+ <para>
+
+ A more recent convention is that these options
+ are available from the generic <filename>pkg-config</filename> program,
+ which has common framework, error handling, and the like,
+ so that all the package creator has to do is provide the set of strings
+ for his particular package.
+
+ </para>
+
+ <para>
+
+ &SCons; construction environments have a &ParseConfig; method
+ that executes a <filename>*config</filename> utility
+ (either <filename>pkg-config</filename> or a
+ more specific utility)
+ and configures the appropriate construction variables
+ in the environment
+ based on the command-line options
+ returned by the specified command.
+
+ </para>
+
+ <programlisting>
+    env = Environment()
+    env['CPPPATH'] = ['/lib/compat']
+    env.ParseConfig("pkg-config x11 --cflags --libs")
+    print env['CPPPATH']
+ </programlisting>
+
+ <para>
+
+ &SCons; will execute the specified command string,
+ parse the resultant flags,
+ and add the flags to the appropriate environment variables.
+
+ </para>
+
+ <screen>
+    % <userinput>scons -Q</userinput>
+    Package x11 was not found in the pkg-config search path.
+    Perhaps you should add the directory containing `x11.pc'
+    to the PKG_CONFIG_PATH environment variable
+    No package 'x11' found
+    OSError: 'pkg-config x11 --cflags --libs' exited 1:
+      File "/home/my/project/SConstruct", line 3:
+        env.ParseConfig("pkg-config x11 --cflags --libs")
+      File "bootstrap/src/engine/SCons/Environment.py", line 1474:
+        None
+      File "bootstrap/src/engine/SCons/Environment.py", line 593:
+        None
+ </screen>
+
+ <para>
+
+ In the example above, &SCons; has added the include directory to
+ <varname>CPPPATH</varname>.
+ (Depending upon what other flags are emitted by the
+ <filename>pkg-config</filename> command,
+ other variables may have been extended as well.)
+
+ </para>
+
+ <para>
+
+ Note that the options are merged with existing options using
+ the &MergeFlags; method,
+ so that each option only occurs once in the construction variable:
+
+ </para>
+
+ <programlisting>
+    env = Environment()
+    env.ParseConfig("pkg-config x11 --cflags --libs")
+    env.ParseConfig("pkg-config x11 --cflags --libs")
+    print env['CPPPATH']
+ </programlisting>
+
+ <screen>
+    % <userinput>scons -Q</userinput>
+    Package x11 was not found in the pkg-config search path.
+    Perhaps you should add the directory containing `x11.pc'
+    to the PKG_CONFIG_PATH environment variable
+    No package 'x11' found
+    OSError: 'pkg-config x11 --cflags --libs' exited 1:
+      File "/home/my/project/SConstruct", line 2:
+        env.ParseConfig("pkg-config x11 --cflags --libs")
+      File "bootstrap/src/engine/SCons/Environment.py", line 1474:
+        None
+      File "bootstrap/src/engine/SCons/Environment.py", line 593:
+        None
+ </screen>
diff --git a/doc/user/parseflags.in b/doc/user/parseflags.in
new file mode 100644
index 0000000..b21df4f
--- /dev/null
+++ b/doc/user/parseflags.in
@@ -0,0 +1,184 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+ &SCons; has a bewildering array of construction variables
+ for different types of options when building programs.
+ Sometimes you may not know exactly which variable
+ should be used for a particular option.
+
+ </para>
+
+ <para>
+
+ &SCons; construction environments have a &ParseFlags; method
+ that takes a set of typical command-line options
+ and distrbutes them into the appropriate construction variables.
+ Historically, it was created to support the &ParseConfig; method,
+ so it focuses on options used by the GNU Compiler Collection (GCC)
+ for the C and C++ toolchains.
+
+ </para>
+
+ <para>
+
+ &ParseFlags; returns a dictionary containing the options
+ distributed into their respective construction variables.
+ Normally, this dictionary would be passed to &MergeFlags;
+ to merge the options into a &consenv;,
+ but the dictionary can be edited if desired to provide
+ additional functionality.
+ (Note that if the flags are not going to be edited,
+ calling &MergeFlags; with the options directly
+ will avoid an additional step.)
+
+ </para>
+
+ <scons_example name="ParseFlags1">
+   <file name="SConstruct" printme="1">
+    env = Environment()
+    d = env.ParseFlags("-I/opt/include -L/opt/lib -lfoo")
+    l = d.items()
+    l.sort()
+    for k,v in l:
+        if v:
+            print k, v
+    env.MergeFlags(d)
+    env.Program('f1.c')
+   </file>
+   <file name="f1.c">
+     int main() { return 0; }
+   </file>
+ </scons_example>
+
+ <scons_output example="ParseFlags1" os="posix">
+    <scons_output_command>scons -Q</scons_output_command>
+ </scons_output>
+
+ <para>
+
+ Note that if the options are limited to generic types
+ like those above,
+ they will be correctly translated for other platform types:
+
+ </para>
+
+ <scons_output example="ParseFlags1" os="win32">
+    <scons_output_command>scons -Q</scons_output_command>
+ </scons_output>
+
+ <para>
+
+ Since the assumption is that the flags are used for the GCC toolchain,
+ unrecognized flags are placed in &cv-link-CCFLAGS;
+ so they will be used for both C and C++ compiles:
+
+ </para>
+
+ <scons_example name="ParseFlags2">
+   <file name="SConstruct" printme="1">
+    env = Environment()
+    d = env.ParseFlags("-whatever")
+    l = d.items()
+    l.sort()
+    for k,v in l:
+        if v:
+            print k, v
+    env.MergeFlags(d)
+    env.Program('f1.c')
+   </file>
+   <file name="f1.c">
+     int main() { return 0; }
+   </file>
+ </scons_example>
+
+ <scons_output example="ParseFlags2">
+    <scons_output_command>scons -Q</scons_output_command>
+ </scons_output>
+
+ <para>
+
+ &ParseFlags; will also accept a (recursive) list of strings as input;
+ the list is flattened before the strings are processed:
+
+ </para>
+
+ <scons_example name="ParseFlags3">
+   <file name="SConstruct" printme="1">
+    env = Environment()
+    d = env.ParseFlags(["-I/opt/include", ["-L/opt/lib", "-lfoo"]])
+    l = d.items()
+    l.sort()
+    for k,v in l:
+        if v:
+            print k, v
+    env.MergeFlags(d)
+    env.Program('f1.c')
+   </file>
+   <file name="f1.c">
+     int main() { return 0; }
+   </file>
+ </scons_example>
+
+ <scons_output example="ParseFlags3">
+    <scons_output_command>scons -Q</scons_output_command>
+ </scons_output>
+
+ <para>
+
+ If a string begins with a "!" (an exclamation mark, often called a bang),
+ the string is passed to the shell for execution.
+ The output of the command is then parsed:
+
+ </para>
+
+ <scons_example name="ParseFlags4">
+   <file name="SConstruct" printme="1">
+    env = Environment()
+    d = env.ParseFlags(["!echo -I/opt/include", "!echo -L/opt/lib", "-lfoo"])
+    l = d.items()
+    l.sort()
+    for k,v in l:
+        if v:
+            print k, v
+    env.MergeFlags(d)
+    env.Program('f1.c')
+   </file>
+   <file name="f1.c">
+     int main() { return 0; }
+   </file>
+ </scons_example>
+
+ <scons_output example="ParseFlags4">
+    <scons_output_command>scons -Q</scons_output_command>
+ </scons_output>
+
+ <para>
+
+ &ParseFlags; is regularly updated for new options;
+ consult the man page for details about those currently recognized.
+
+ </para>
diff --git a/doc/user/parseflags.xml b/doc/user/parseflags.xml
new file mode 100644
index 0000000..6900291
--- /dev/null
+++ b/doc/user/parseflags.xml
@@ -0,0 +1,199 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+ &SCons; has a bewildering array of construction variables
+ for different types of options when building programs.
+ Sometimes you may not know exactly which variable
+ should be used for a particular option.
+
+ </para>
+
+ <para>
+
+ &SCons; construction environments have a &ParseFlags; method
+ that takes a set of typical command-line options
+ and distrbutes them into the appropriate construction variables.
+ Historically, it was created to support the &ParseConfig; method,
+ so it focuses on options used by the GNU Compiler Collection (GCC)
+ for the C and C++ toolchains.
+
+ </para>
+
+ <para>
+
+ &ParseFlags; returns a dictionary containing the options
+ distributed into their respective construction variables.
+ Normally, this dictionary would be passed to &MergeFlags;
+ to merge the options into a &consenv;,
+ but the dictionary can be edited if desired to provide
+ additional functionality.
+ (Note that if the flags are not going to be edited,
+ calling &MergeFlags; with the options directly
+ will avoid an additional step.)
+
+ </para>
+
+ <programlisting>
+    env = Environment()
+    d = env.ParseFlags("-I/opt/include -L/opt/lib -lfoo")
+    l = d.items()
+    l.sort()
+    for k,v in l:
+        if v:
+            print k, v
+    env.MergeFlags(d)
+    env.Program('f1.c')
+ </programlisting>
+
+ <screen>
+    % <userinput>scons -Q</userinput>
+    CPPPATH ['/opt/include']
+    LIBPATH ['/opt/lib']
+    LIBS ['foo']
+    cc -o f1.o -c -I/opt/include f1.c
+    cc -o f1 f1.o -L/opt/lib -lfoo
+ </screen>
+
+ <para>
+
+ Note that if the options are limited to generic types
+ like those above,
+ they will be correctly translated for other platform types:
+
+ </para>
+
+ <screen>
+    C:\><userinput>scons -Q</userinput>
+    
+    scons: warning: No installed VCs
+    File "&lt;stdin&gt;", line 67, in __call__
+    
+    scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+    File "&lt;stdin&gt;", line 67, in __call__
+    
+    scons: warning: No installed VCs
+    File "&lt;stdin&gt;", line 67, in __call__
+    
+    scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+    File "&lt;stdin&gt;", line 67, in __call__
+    CPPPATH ['/opt/include']
+    LIBPATH ['/opt/lib']
+    LIBS ['foo']
+    cl /Fof1.obj /c f1.c /nologo /I\opt\include
+    link /nologo /OUT:f1.exe /LIBPATH:\opt\lib foo.lib f1.obj
+ </screen>
+
+ <para>
+
+ Since the assumption is that the flags are used for the GCC toolchain,
+ unrecognized flags are placed in &cv-link-CCFLAGS;
+ so they will be used for both C and C++ compiles:
+
+ </para>
+
+ <programlisting>
+    env = Environment()
+    d = env.ParseFlags("-whatever")
+    l = d.items()
+    l.sort()
+    for k,v in l:
+        if v:
+            print k, v
+    env.MergeFlags(d)
+    env.Program('f1.c')
+ </programlisting>
+
+ <screen>
+    % <userinput>scons -Q</userinput>
+    CCFLAGS -whatever
+    cc -o f1.o -c -whatever f1.c
+    cc -o f1 f1.o
+ </screen>
+
+ <para>
+
+ &ParseFlags; will also accept a (recursive) list of strings as input;
+ the list is flattened before the strings are processed:
+
+ </para>
+
+ <programlisting>
+    env = Environment()
+    d = env.ParseFlags(["-I/opt/include", ["-L/opt/lib", "-lfoo"]])
+    l = d.items()
+    l.sort()
+    for k,v in l:
+        if v:
+            print k, v
+    env.MergeFlags(d)
+    env.Program('f1.c')
+ </programlisting>
+
+ <screen>
+    % <userinput>scons -Q</userinput>
+    CPPPATH ['/opt/include']
+    LIBPATH ['/opt/lib']
+    LIBS ['foo']
+    cc -o f1.o -c -I/opt/include f1.c
+    cc -o f1 f1.o -L/opt/lib -lfoo
+ </screen>
+
+ <para>
+
+ If a string begins with a "!" (an exclamation mark, often called a bang),
+ the string is passed to the shell for execution.
+ The output of the command is then parsed:
+
+ </para>
+
+ <programlisting>
+    env = Environment()
+    d = env.ParseFlags(["!echo -I/opt/include", "!echo -L/opt/lib", "-lfoo"])
+    l = d.items()
+    l.sort()
+    for k,v in l:
+        if v:
+            print k, v
+    env.MergeFlags(d)
+    env.Program('f1.c')
+ </programlisting>
+
+ <screen>
+    % <userinput>scons -Q</userinput>
+    CPPPATH ['/opt/include']
+    LIBPATH ['/opt/lib']
+    LIBS ['foo']
+    cc -o f1.o -c -I/opt/include f1.c
+    cc -o f1 f1.o -L/opt/lib -lfoo
+ </screen>
+
+ <para>
+
+ &ParseFlags; is regularly updated for new options;
+ consult the man page for details about those currently recognized.
+
+ </para>
diff --git a/doc/user/preface.in b/doc/user/preface.in
new file mode 100644
index 0000000..de4cb43
--- /dev/null
+++ b/doc/user/preface.in
@@ -0,0 +1,426 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  Thank you for taking the time to read about &SCons;.
+  &SCons; is a next-generation
+  software construction tool,
+  or make tool--that is, a software utility
+  for building software (or other files)
+  and keeping built software up-to-date
+  whenever the underlying input files change.
+
+  </para>
+
+  <para>
+
+  The most distinctive thing about &SCons;
+  is that its configuration files are
+  actually <emphasis>scripts</emphasis>,
+  written in the &Python; programming language.
+  This is in contrast to most alternative build tools,
+  which typically invent a new language to
+  configure the build.
+  &SCons; still has a learning curve, of course,
+  because you have to know what functions to call
+  to set up your build properly,
+  but the underlying syntax used should be familiar
+  to anyone who has ever looked at a Python script.
+
+  </para>
+
+  <para>
+
+  Paradoxically,
+  using Python as the configuration file format
+  makes &SCons;
+  <emphasis>easier</emphasis>
+  for non-programmers to learn
+  than the cryptic languages of other build tools,
+  which are usually invented by programmers for other programmers.
+  This is in no small part due to the
+  consistency and readability that are hallmarks of Python.
+  It just so happens that making a real, live
+  scripting language the basis for the
+  configuration files
+  makes it a snap for more accomplished programmers
+  to do more complicated things with builds,
+  as necessary.
+
+  </para>
+
+  <!--
+
+  <section>
+  <title>Why &SCons;?</title>
+
+    <para>
+
+    &SCons; is a response to a perennial problem:
+    building software is harder than it should be.
+    In a nutshell:  the old, reliable model of the
+    venerable and ubiquitous &Make; program
+    has had a hard time keeping up with
+    how complicated building software has become.
+    The fact that &Make; has kept up as well as it has is impressive,
+    and a testament to how the simplicity.
+    But anyone who has wrestled with &Automake; and &Autoconf;
+    to try to guarantee that a bit of software
+    will build correctly on multiple platforms
+    can tell you that it takes a lot of work to get right.
+
+    </para>
+
+  </section>
+
+  -->
+
+  <section>
+  <title>&SCons; Principles</title>
+
+    <para>
+
+    There are a few overriding principles
+    we try to live up to in designing and implementing &SCons:
+
+    </para>
+
+    <variablelist>
+
+      <varlistentry>
+      <term>Correctness</term>
+
+      <listitem>
+      <para>
+
+      First and foremost,
+      by default, &SCons; guarantees a correct build
+      even if it means sacrificing performance a little.
+      We strive to guarantee the build is correct
+      regardless of how the software being built is structured,
+      how it may have been written,
+      or how unusual the tools are that build it.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>Performance</term>
+
+      <listitem>
+      <para>
+
+      Given that the build is correct,
+      we try to make &SCons; build software
+      as quickly as possible.
+      In particular, wherever we may have needed to slow
+      down the default &SCons; behavior to guarantee a correct build,
+      we also try to make it easy to speed up &SCons;
+      through optimization options that let you trade off
+      guaranteed correctness in all end cases for
+      a speedier build in the usual cases.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>Convenience</term>
+
+      <listitem>
+      <para>
+
+      &SCons; tries to do as much for you out of the box as reasonable,
+      including detecting the right tools on your system
+      and using them correctly to build the software.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+    </variablelist>
+
+    <para>
+
+    In a nutshell, we try hard to make &SCons; just
+    "do the right thing" and build software correctly,
+    with a minimum of hassles.
+
+    </para>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>History</title>
+
+    <para>
+
+    &SCons; originated with a design
+    that was submitted to the Software Carpentry
+    design competition in 2000.
+
+    </para>
+
+    <para>
+
+    &SCons; is the direct descendant
+    of a Perl utility called &Cons;.
+    &Cons; in turn based some of its ideas on &Jam;,
+    a build tool from Perforce Systems.
+
+    </para>
+
+    <para>
+
+    XXX history of SCons
+
+    </para>
+
+  </section>
+
+  -->
+
+  <!--
+
+  <section>
+  <title>Conventions</title>
+
+    <para>
+
+    XXX conventions used in this manual
+
+    </para>
+
+  </section>
+
+  -->
+
+  <section>
+  <title>A Caveat About This Guide's Completeness</title>
+
+  <para>
+
+  One word of warning as you read through this Guide:
+  Like too much Open Source software out there,
+  the &SCons; documentation isn't always
+  kept up-to-date with the available features.
+  In other words,
+  there's a lot that &SCons; can do that
+  isn't yet covered in this User's Guide.
+  (Come to think of it,
+  that also describes a lot of proprietary software, doesn't it?)
+
+  </para>
+
+  <para>
+
+  Although this User's Guide isn't as complete as we'd like it to be,
+  our development process does emphasize
+  making sure that the &SCons; man page is kept up-to-date
+  with new features.
+  So if you're trying to figure out how to do something
+  that &SCons; supports
+  but can't find enough (or any) information here,
+  it would be worth your while to look
+  at the man page to see if the information is covered there.
+  And if you do,
+  maybe you'd even consider contributing
+  a section to the User's Guide
+  so the next person looking for
+  that information won't have to
+  go through the same thing...?
+
+  </para>
+
+  </section>
+
+  <section>
+  <title>Acknowledgements</title>
+
+    <para>
+
+    &SCons; would not exist without a lot of help
+    from a lot of people,
+    many of whom may not even be aware
+    that they helped or served as inspiration.
+    So in no particular order,
+    and at the risk of leaving out someone:
+
+    </para>
+
+    <para>
+
+    First and foremost,
+    &SCons; owes a tremendous debt to Bob Sidebotham,
+    the original author of the classic Perl-based &Cons; tool
+    which Bob first released to the world back around 1996.
+    Bob's work on Cons classic provided the underlying architecture
+    and model of specifying a build configuration
+    using a real scripting language.
+    My real-world experience working on Cons
+    informed many of the design decisions in SCons,
+    including the improved parallel build support,
+    making Builder objects easily definable by users,
+    and separating the build engine from the wrapping interface.
+
+    </para>
+
+    <para>
+
+    Greg Wilson was instrumental in getting
+    &SCons; started as a real project
+    when he initiated the Software Carpentry design
+    competition in February 2000.
+    Without that nudge,
+    marrying the advantages of the Cons classic
+    architecture with the readability of Python
+    might have just stayed no more than a nice idea.
+
+    </para>
+
+    <para>
+
+    The entire &SCons; team have been
+    absolutely wonderful to work with,
+    and &SCons; would be nowhere near as useful a
+    tool without the energy, enthusiasm
+    and time people have contributed over the past few years.
+    The "core team"
+    of Chad Austin, Anthony Roach,
+    Bill Deegan, Charles Crain, Steve Leblanc, Greg Noel,
+    Gary Oberbrunner, Greg Spencer and Christoph Wiedemann
+    have been great about reviewing my (and other) changes
+    and catching problems before they get in the code base.
+    Of particular technical note:
+    Anthony's outstanding and innovative work on the tasking engine
+    has given &SCons; a vastly superior parallel build model;
+    Charles has been the master of the crucial Node infrastructure;
+    Christoph's work on the Configure infrastructure
+    has added crucial Autoconf-like functionality;
+    and Greg has provided excellent support
+    for Microsoft Visual Studio.
+
+    </para>
+
+    <para>
+
+    Special thanks to David Snopek for contributing
+    his underlying "Autoscons" code that formed
+    the basis of Christoph's work with the Configure functionality.
+    David was extremely generous in making
+    this code available to &SCons;,
+    given that he initially released it under the GPL
+    and &SCons; is released under a less-restrictive MIT-style license.
+
+    </para>
+
+    <!--
+
+    <para>
+
+    &SCons; has received contributions
+    from many other people, of course:
+    Matt Balvin (extending long command-line support on Windows),
+    Allen Bierbaum (extensions and fixes to Options),
+    Steve Christensen (help text sorting and function action signature fixes),
+    Michael Cook (avoiding losing signal bits from executed commands),
+    Derrick 'dman' Hudson (),
+    Alex Jacques (work on the Windows scons.bat file),
+    Stephen Kennedy (performance enhancements),
+    Lachlan O'Dea (SharedObject() support for masm
+    and normalized paths for the WhereIs() function),
+    Damyan Pepper (keeping output like Make),
+    Jeff Petkau (significant fixes for CacheDir and other areas),
+    Stefan Reichor (Ghostscript support),
+    Zed Shaw (Append() and Replace() environment methods),
+    Terrel Shumway (build and test fixes, as well as the SCons Wiki)
+    and
+    sam th (dynamic checks for utilities).
+
+    </para>
+
+    -->
+
+    <para>
+
+    Thanks to Peter Miller
+    for his splendid change management system, &Aegis;,
+    which has provided the &SCons; project
+    with a robust development methodology from day one,
+    and which showed me how you could
+    integrate incremental regression tests into
+    a practical development cycle
+    (years before eXtreme Programming arrived on the scene).
+
+    </para>
+
+    <para>
+
+    And last, thanks to Guido van Rossum
+    for his elegant scripting language,
+    which is the basis not only for the &SCons; implementation,
+    but for the interface itself.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Contact</title>
+
+    <para>
+
+    The best way to contact people involved with SCons,
+    including the author,
+    is through the SCons mailing lists.
+
+    </para>
+
+    <para>
+
+    If you want to ask general questions about how to use &SCons;
+    send email to &scons-users;.
+
+    </para>
+
+    <para>
+
+    If you want to contact the &SCons; development community directly,
+    send email to &scons-devel;.
+
+    </para>
+
+    <para>
+
+    If you want to receive announcements about &SCons,
+    join the low-volume &scons-announce; mailing list.
+
+    </para>
+
+  </section>
diff --git a/doc/user/preface.xml b/doc/user/preface.xml
new file mode 100644
index 0000000..2c6d8f4
--- /dev/null
+++ b/doc/user/preface.xml
@@ -0,0 +1,426 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  Thank you for taking the time to read about &SCons;.
+  &SCons; is a next-generation
+  software construction tool,
+  or make tool--that is, a software utility
+  for building software (or other files)
+  and keeping built software up-to-date
+  whenever the underlying input files change.
+
+  </para>
+
+  <para>
+
+  The most distinctive thing about &SCons;
+  is that its configuration files are
+  actually <emphasis>scripts</emphasis>,
+  written in the &Python; programming language.
+  This is in contrast to most alternative build tools,
+  which typically invent a new language to
+  configure the build.
+  &SCons; still has a learning curve, of course,
+  because you have to know what functions to call
+  to set up your build properly,
+  but the underlying syntax used should be familiar
+  to anyone who has ever looked at a Python script.
+
+  </para>
+
+  <para>
+
+  Paradoxically,
+  using Python as the configuration file format
+  makes &SCons;
+  <emphasis>easier</emphasis>
+  for non-programmers to learn
+  than the cryptic languages of other build tools,
+  which are usually invented by programmers for other programmers.
+  This is in no small part due to the
+  consistency and readability that are hallmarks of Python.
+  It just so happens that making a real, live
+  scripting language the basis for the
+  configuration files
+  makes it a snap for more accomplished programmers
+  to do more complicated things with builds,
+  as necessary.
+
+  </para>
+
+  <!--
+
+  <section>
+  <title>Why &SCons;?</title>
+
+    <para>
+
+    &SCons; is a response to a perennial problem:
+    building software is harder than it should be.
+    In a nutshell:  the old, reliable model of the
+    venerable and ubiquitous &Make; program
+    has had a hard time keeping up with
+    how complicated building software has become.
+    The fact that &Make; has kept up as well as it has is impressive,
+    and a testament to how the simplicity.
+    But anyone who has wrestled with &Automake; and &Autoconf;
+    to try to guarantee that a bit of software
+    will build correctly on multiple platforms
+    can tell you that it takes a lot of work to get right.
+
+    </para>
+
+  </section>
+
+  -->
+
+  <section>
+  <title>&SCons; Principles</title>
+
+    <para>
+
+    There are a few overriding principles
+    we try to live up to in designing and implementing &SCons;:
+
+    </para>
+
+    <variablelist>
+
+      <varlistentry>
+      <term>Correctness</term>
+
+      <listitem>
+      <para>
+
+      First and foremost,
+      by default, &SCons; guarantees a correct build
+      even if it means sacrificing performance a little.
+      We strive to guarantee the build is correct
+      regardless of how the software being built is structured,
+      how it may have been written,
+      or how unusual the tools are that build it.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>Performance</term>
+
+      <listitem>
+      <para>
+
+      Given that the build is correct,
+      we try to make &SCons; build software
+      as quickly as possible.
+      In particular, wherever we may have needed to slow
+      down the default &SCons; behavior to guarantee a correct build,
+      we also try to make it easy to speed up &SCons;
+      through optimization options that let you trade off
+      guaranteed correctness in all end cases for
+      a speedier build in the usual cases.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>Convenience</term>
+
+      <listitem>
+      <para>
+
+      &SCons; tries to do as much for you out of the box as reasonable,
+      including detecting the right tools on your system
+      and using them correctly to build the software.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+    </variablelist>
+
+    <para>
+
+    In a nutshell, we try hard to make &SCons; just
+    "do the right thing" and build software correctly,
+    with a minimum of hassles.
+
+    </para>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>History</title>
+
+    <para>
+
+    &SCons; originated with a design
+    that was submitted to the Software Carpentry
+    design competition in 2000.
+
+    </para>
+
+    <para>
+
+    &SCons; is the direct descendant
+    of a Perl utility called &Cons;.
+    &Cons; in turn based some of its ideas on &Jam;,
+    a build tool from Perforce Systems.
+
+    </para>
+
+    <para>
+
+    XXX history of SCons
+
+    </para>
+
+  </section>
+
+  -->
+
+  <!--
+
+  <section>
+  <title>Conventions</title>
+
+    <para>
+
+    XXX conventions used in this manual
+
+    </para>
+
+  </section>
+
+  -->
+
+  <section>
+  <title>A Caveat About This Guide's Completeness</title>
+
+  <para>
+
+  One word of warning as you read through this Guide:
+  Like too much Open Source software out there,
+  the &SCons; documentation isn't always
+  kept up-to-date with the available features.
+  In other words,
+  there's a lot that &SCons; can do that
+  isn't yet covered in this User's Guide.
+  (Come to think of it,
+  that also describes a lot of proprietary software, doesn't it?)
+
+  </para>
+
+  <para>
+
+  Although this User's Guide isn't as complete as we'd like it to be,
+  our development process does emphasize
+  making sure that the &SCons; man page is kept up-to-date
+  with new features.
+  So if you're trying to figure out how to do something
+  that &SCons; supports
+  but can't find enough (or any) information here,
+  it would be worth your while to look
+  at the man page to see if the information is covered there.
+  And if you do,
+  maybe you'd even consider contributing
+  a section to the User's Guide
+  so the next person looking for
+  that information won't have to
+  go through the same thing...?
+
+  </para>
+
+  </section>
+
+  <section>
+  <title>Acknowledgements</title>
+
+    <para>
+
+    &SCons; would not exist without a lot of help
+    from a lot of people,
+    many of whom may not even be aware
+    that they helped or served as inspiration.
+    So in no particular order,
+    and at the risk of leaving out someone:
+
+    </para>
+
+    <para>
+
+    First and foremost,
+    &SCons; owes a tremendous debt to Bob Sidebotham,
+    the original author of the classic Perl-based &Cons; tool
+    which Bob first released to the world back around 1996.
+    Bob's work on Cons classic provided the underlying architecture
+    and model of specifying a build configuration
+    using a real scripting language.
+    My real-world experience working on Cons
+    informed many of the design decisions in SCons,
+    including the improved parallel build support,
+    making Builder objects easily definable by users,
+    and separating the build engine from the wrapping interface.
+
+    </para>
+
+    <para>
+
+    Greg Wilson was instrumental in getting
+    &SCons; started as a real project
+    when he initiated the Software Carpentry design
+    competition in February 2000.
+    Without that nudge,
+    marrying the advantages of the Cons classic
+    architecture with the readability of Python
+    might have just stayed no more than a nice idea.
+
+    </para>
+
+    <para>
+
+    The entire &SCons; team have been
+    absolutely wonderful to work with,
+    and &SCons; would be nowhere near as useful a
+    tool without the energy, enthusiasm
+    and time people have contributed over the past few years.
+    The "core team"
+    of Chad Austin, Anthony Roach,
+    Bill Deegan, Charles Crain, Steve Leblanc, Greg Noel,
+    Gary Oberbrunner, Greg Spencer and Christoph Wiedemann
+    have been great about reviewing my (and other) changes
+    and catching problems before they get in the code base.
+    Of particular technical note:
+    Anthony's outstanding and innovative work on the tasking engine
+    has given &SCons; a vastly superior parallel build model;
+    Charles has been the master of the crucial Node infrastructure;
+    Christoph's work on the Configure infrastructure
+    has added crucial Autoconf-like functionality;
+    and Greg has provided excellent support
+    for Microsoft Visual Studio.
+
+    </para>
+
+    <para>
+
+    Special thanks to David Snopek for contributing
+    his underlying "Autoscons" code that formed
+    the basis of Christoph's work with the Configure functionality.
+    David was extremely generous in making
+    this code available to &SCons;,
+    given that he initially released it under the GPL
+    and &SCons; is released under a less-restrictive MIT-style license.
+
+    </para>
+
+    <!--
+
+    <para>
+
+    &SCons; has received contributions
+    from many other people, of course:
+    Matt Balvin (extending long command-line support on Windows),
+    Allen Bierbaum (extensions and fixes to Options),
+    Steve Christensen (help text sorting and function action signature fixes),
+    Michael Cook (avoiding losing signal bits from executed commands),
+    Derrick 'dman' Hudson (),
+    Alex Jacques (work on the Windows scons.bat file),
+    Stephen Kennedy (performance enhancements),
+    Lachlan O'Dea (SharedObject() support for masm
+    and normalized paths for the WhereIs() function),
+    Damyan Pepper (keeping output like Make),
+    Jeff Petkau (significant fixes for CacheDir and other areas),
+    Stefan Reichor (Ghostscript support),
+    Zed Shaw (Append() and Replace() environment methods),
+    Terrel Shumway (build and test fixes, as well as the SCons Wiki)
+    and
+    sam th (dynamic checks for utilities).
+
+    </para>
+
+    -->
+
+    <para>
+
+    Thanks to Peter Miller
+    for his splendid change management system, &Aegis;,
+    which has provided the &SCons; project
+    with a robust development methodology from day one,
+    and which showed me how you could
+    integrate incremental regression tests into
+    a practical development cycle
+    (years before eXtreme Programming arrived on the scene).
+
+    </para>
+
+    <para>
+
+    And last, thanks to Guido van Rossum
+    for his elegant scripting language,
+    which is the basis not only for the &SCons; implementation,
+    but for the interface itself.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Contact</title>
+
+    <para>
+
+    The best way to contact people involved with SCons,
+    including the author,
+    is through the SCons mailing lists.
+
+    </para>
+
+    <para>
+
+    If you want to ask general questions about how to use &SCons;
+    send email to &scons-users;.
+
+    </para>
+
+    <para>
+
+    If you want to contact the &SCons; development community directly,
+    send email to &scons-devel;.
+
+    </para>
+
+    <para>
+
+    If you want to receive announcements about &SCons;,
+    join the low-volume &scons-announce; mailing list.
+
+    </para>
+
+  </section>
diff --git a/doc/user/python.in b/doc/user/python.in
new file mode 100644
index 0000000..aa49030
--- /dev/null
+++ b/doc/user/python.in
@@ -0,0 +1,154 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <!--
+
+  <section>
+  <title>Python Overview</title>
+
+    <para>
+
+    This section will provide a brief overview of
+    the Python programming language.
+    Skip this section if you are already familiar with Python
+    (or you're really intent on diving into &SCons;
+    and just picking up things as you go).
+
+    </para>
+
+    <para>
+
+    Python has a lot of good
+    documentation freely available on-line
+    to help you get started.
+    The standard tutorial is available at XXX.
+
+
+    </para>
+
+    <para>
+
+    Python is very easy to pick up.
+
+    </para>
+
+    <para>
+
+    Python variables must be assigned to before they can be referenced.
+
+    </para>
+
+    <para>
+
+    Assignment is like most programming languages:
+
+    x = 1 + 2
+    z = 3 * x
+
+    </para>
+
+    <para>
+
+    Function calls look like most language function calls:
+
+    a = f(g)
+
+    </para>
+
+    <para>
+
+    Define functions like so:
+
+        def func(arg1, arg2):
+            return arg1 * arg 2
+
+    The number of parameters
+
+    </para>
+
+    <para>
+
+    Strings can be enclosed in single quotes or double quotes,
+    backslashes are used to escape characters,
+    triple-quote syntax lets you include quotes and newlines,
+    raw strings begin with 'r'.
+
+    </para>
+
+    <para>
+
+    Lists are enclosed in square brackets,
+    list items are separated by commas.
+    List references use square brackets and integer index values,
+    slice notation lets you select, delete or replace a range.
+
+    </para>
+
+    <para>
+
+    Dictionaries (hashes) are enclosed in curly brackets,
+    : separates keys from values,
+    , separates items.
+    Dictionary values are referenced using square brackets.
+
+    </para>
+
+    <para>
+
+    Access class attributes (including methods) using a '.'.
+
+    </para>
+
+    <para>
+
+    if: statements look like
+
+    elif: statements look like
+
+    else: statements look like
+
+    </para>
+
+    <para>
+
+    for: statements look like
+
+    while: statements look like
+
+    break statements look like
+    
+    continue statements look like
+
+    </para>
+
+    <para>
+
+    pass
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/python.xml b/doc/user/python.xml
new file mode 100644
index 0000000..aa49030
--- /dev/null
+++ b/doc/user/python.xml
@@ -0,0 +1,154 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <!--
+
+  <section>
+  <title>Python Overview</title>
+
+    <para>
+
+    This section will provide a brief overview of
+    the Python programming language.
+    Skip this section if you are already familiar with Python
+    (or you're really intent on diving into &SCons;
+    and just picking up things as you go).
+
+    </para>
+
+    <para>
+
+    Python has a lot of good
+    documentation freely available on-line
+    to help you get started.
+    The standard tutorial is available at XXX.
+
+
+    </para>
+
+    <para>
+
+    Python is very easy to pick up.
+
+    </para>
+
+    <para>
+
+    Python variables must be assigned to before they can be referenced.
+
+    </para>
+
+    <para>
+
+    Assignment is like most programming languages:
+
+    x = 1 + 2
+    z = 3 * x
+
+    </para>
+
+    <para>
+
+    Function calls look like most language function calls:
+
+    a = f(g)
+
+    </para>
+
+    <para>
+
+    Define functions like so:
+
+        def func(arg1, arg2):
+            return arg1 * arg 2
+
+    The number of parameters
+
+    </para>
+
+    <para>
+
+    Strings can be enclosed in single quotes or double quotes,
+    backslashes are used to escape characters,
+    triple-quote syntax lets you include quotes and newlines,
+    raw strings begin with 'r'.
+
+    </para>
+
+    <para>
+
+    Lists are enclosed in square brackets,
+    list items are separated by commas.
+    List references use square brackets and integer index values,
+    slice notation lets you select, delete or replace a range.
+
+    </para>
+
+    <para>
+
+    Dictionaries (hashes) are enclosed in curly brackets,
+    : separates keys from values,
+    , separates items.
+    Dictionary values are referenced using square brackets.
+
+    </para>
+
+    <para>
+
+    Access class attributes (including methods) using a '.'.
+
+    </para>
+
+    <para>
+
+    if: statements look like
+
+    elif: statements look like
+
+    else: statements look like
+
+    </para>
+
+    <para>
+
+    for: statements look like
+
+    while: statements look like
+
+    break statements look like
+    
+    continue statements look like
+
+    </para>
+
+    <para>
+
+    pass
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/repositories.in b/doc/user/repositories.in
new file mode 100644
index 0000000..8c97b02
--- /dev/null
+++ b/doc/user/repositories.in
@@ -0,0 +1,641 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  Often, a software project will have
+  one or more central repositories,
+  directory trees that contain
+  source code, or derived files, or both.
+  You can eliminate additional unnecessary
+  rebuilds of files by having &SCons;
+  use files from one or more code repositories
+  to build files in your local build tree.
+
+  </para>
+
+  <section>
+  <title>The &Repository; Method</title>
+
+ <!--
+
+ The repository directories specified may contain source files, derived files
+ (objects, libraries and executables), or both.  If there is no local file
+ (source or derived) under the directory in which Cons is executed, then the
+ first copy of a same-named file found under a repository directory will be
+ used to build any local derived files.
+
+ -->
+
+    <para>
+
+    It's often useful to allow multiple programmers working
+    on a project to build software from
+    source files and/or derived files that
+    are stored in a centrally-accessible repository,
+    a directory copy of the source code tree.
+    (Note that this is not the sort of repository
+    maintained by a source code management system
+    like BitKeeper, CVS, or Subversion.)
+    <!--
+    For information about using &SCons;
+    with these systems, see the section,
+    "Fetching Files From Source Code Management Systems,"
+    below.)
+    -->
+    You use the &Repository; method
+    to tell &SCons; to search one or more
+    central code repositories (in order)
+    for any source files and derived files
+    that are not present in the local build tree:
+
+    </para>
+
+    <scons_example name="ex1">
+      <file name="SConstruct" printme="1">
+       env = Environment()
+       env.Program('hello.c')
+       Repository('__ROOT__/usr/repository1', '__ROOT__/usr/repository2')
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Multiple calls to the &Repository; method
+    will simply add repositories to the global list
+    that &SCons; maintains,
+    with the exception that &SCons; will automatically eliminate
+    the current directory and any non-existent
+    directories from the list.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Finding source files in repositories</title>
+
+    <para>
+
+    The above example
+    specifies that &SCons;
+    will first search for files under
+    the <filename>/usr/repository1</filename> tree
+    and next under the <filename>/usr/repository2</filename> tree.
+    &SCons; expects that any files it searches
+    for will be found in the same position
+    relative to the top-level directory.
+    In the above example, if the &hello_c; file is not
+    found in the local build tree,
+    &SCons; will search first for
+    a <filename>/usr/repository1/hello.c</filename> file
+    and then for a <filename>/usr/repository2/hello.c</filename> file
+    to use in its place.
+
+    </para>
+
+    <para>
+
+    So given the &SConstruct; file above,
+    if the &hello_c; file exists in the local
+    build directory,
+    &SCons; will rebuild the &hello; program
+    as normal:
+
+    </para>
+
+    <scons_output example="ex1">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    If, however, there is no local &hello_c; file,
+    but one exists in <filename>/usr/repository1</filename>,
+    &SCons; will recompile the &hello; program
+    from the source file it finds in the repository:
+
+    </para>
+
+    <scons_example name="ex2">
+      <file name="SConstruct">
+       env = Environment()
+       env.Program('hello.c')
+       Repository('__ROOT__/usr/repository1', '__ROOT__/usr/repository2')
+      </file>
+      <file name="__ROOT__/usr/repository1/hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <scons_output example="ex2">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    And similarly, if there is no local &hello_c; file
+    and no <filename>/usr/repository1/hello.c</filename>,
+    but one exists in <filename>/usr/repository2</filename>:
+
+    </para>
+
+    <scons_example name="ex3">
+      <file name="SConstruct">
+       env = Environment()
+       env.Program('hello.c')
+       Repository('__ROOT__/usr/repository1', '__ROOT__/usr/repository2')
+      </file>
+      <file name="__ROOT__/usr/repository2/hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <scons_output example="ex3">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Finding <literal>#include</literal> files in repositories</title>
+
+    <para>
+
+    We've already seen that SCons will scan the contents of
+    a source file for <literal>#include</literal> file names
+    and realize that targets built from that source file
+    also depend on the <literal>#include</literal> file(s).
+    For each directory in the &cv-link-CPPPATH; list,
+    &SCons; will actually search the corresponding directories
+    in any repository trees and establish the
+    correct dependencies on any
+    <literal>#include</literal> files that it finds
+    in repository directory.
+
+    </para>
+
+    <para>
+
+    Unless the C compiler also knows about these directories
+    in the repository trees, though,
+    it will be unable to find the <literal>#include</literal> files.
+    If, for example, the &hello_c; file in
+    our previous example includes the &hello.h;
+    in its current directory,
+    and the &hello.h; only exists in the repository:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c hello.c
+      hello.c:1: hello.h: No such file or directory
+    </screen>
+
+    <para>
+
+    In order to inform the C compiler about the repositories,
+    &SCons; will add appropriate
+    <literal>-I</literal> flags to the compilation commands
+    for each directory in the &cv-CPPPATH; list.
+    So if we add the current directory to the
+    construction environment &cv-CPPPATH; like so:
+
+    </para>
+
+    <scons_example name="CPPPATH">
+      <file name="SConstruct" printme="1">
+       env = Environment(CPPPATH = ['.'])
+       env.Program('hello.c')
+       Repository('__ROOT__/usr/repository1')
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Then re-executing &SCons; yields:
+
+    </para>
+
+    <scons_output example="CPPPATH">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The order of the <literal>-I</literal> options replicates,
+    for the C preprocessor,
+    the same repository-directory search path
+    that &SCons; uses for its own dependency analysis.
+    If there are multiple repositories and multiple &cv-CPPPATH;
+    directories, &SCons; will add the repository directories
+    to the beginning of each &cv-CPPPATH; directory,
+    rapidly multiplying the number of <literal>-I</literal> flags.
+    If, for example, the &cv-CPPPATH; contains three directories
+    (and shorter repository path names!):
+
+    </para>
+
+    <scons_example name="CPPPATH3">
+      <file name="SConstruct" printme="1">
+       env = Environment(CPPPATH = ['dir1', 'dir2', 'dir3'])
+       env.Program('hello.c')
+       Repository('__ROOT__/r1', '__ROOT__/r2')
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Then we'll end up with nine <literal>-I</literal> options
+    on the command line,
+    three (for each of the &cv-CPPPATH; directories)
+    times three (for the local directory plus the two repositories):
+
+    </para>
+
+    <scons_output example="CPPPATH3">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+<!--
+
+Cons classic did the following, does SCons?
+
+In order to shorten the command lines as much as possible, Cons will
+remove C<-I> flags for any directories, locally or in the repositories,
+which do not actually exist.  (Note that the C<-I> flags are not included
+in the MD5 signature calculation for the target file, so the target will
+not be recompiled if the compilation command changes due to a directory
+coming into existence.)
+
+-->
+
+    <section>
+    <title>Limitations on <literal>#include</literal> files in repositories</title>
+
+      <para>
+
+      &SCons; relies on the C compiler's
+      <literal>-I</literal> options to control the order in which
+      the preprocessor will search the repository directories
+      for <literal>#include</literal> files.
+      This causes a problem, however, with how the C preprocessor
+      handles <literal>#include</literal> lines with
+      the file name included in double-quotes.
+
+      </para>
+
+      <para>
+
+      As we've seen,
+      &SCons; will compile the &hello_c; file from
+      the repository if it doesn't exist in
+      the local directory.
+      If, however, the &hello_c; file in the repository contains
+      a <literal>#include</literal> line with the file name in
+      double quotes:
+
+      </para>
+
+      <programlisting>
+        #include "hello.h"
+        int
+        main(int argc, char *argv[])
+        {
+            printf(HELLO_MESSAGE);
+            return (0);
+        }
+      </programlisting>
+
+      <para>
+
+      Then the C preprocessor will <emphasis>always</emphasis>
+      use a &hello_h; file from the repository directory first,
+      even if there is a &hello_h; file in the local directory,
+      despite the fact that the command line specifies
+      <literal>-I</literal> as the first option:
+
+      </para>
+
+      <scons_example name="quote1">
+        <file name="SConstruct">
+         env = Environment(CPPPATH = ['.'])
+         env.Program('hello.c')
+         Repository('__ROOT__/usr/repository1')
+        </file>
+        <file name="__ROOT__/usr/repository1/hello.c">
+        int main() { printf("Hello, world!\n"); }
+        </file>
+      </scons_example>
+
+      <scons_output example="quote1">
+        <scons_output_command>scons -Q</scons_output_command>
+      </scons_output>
+
+      <para>
+
+      This behavior of the C preprocessor--always search
+      for a <literal>#include</literal> file in double-quotes
+      first in the same directory as the source file,
+      and only then search the <literal>-I</literal>--can
+      not, in general, be changed.
+      In other words, it's a limitation
+      that must be lived with if you want to use
+      code repositories in this way.
+      There are three ways you can possibly
+      work around this C preprocessor behavior:
+
+      </para>
+
+      <orderedlist>
+
+        <listitem>
+        <para>
+
+        Some modern versions of C compilers do have an option
+        to disable or control this behavior.
+        If so, add that option to &cv-link-CFLAGS;
+        (or &cv-link-CXXFLAGS; or both) in your construction environment(s).
+        Make sure the option is used for all construction
+        environments that use C preprocessing!
+
+        </para>
+        </listitem>
+
+        <listitem>
+        <para>
+
+        Change all occurrences of <literal>#include "file.h"</literal>
+        to <literal>#include &amp;lt;file.h&amp;gt;</literal>.
+        Use of <literal>#include</literal> with angle brackets
+        does not have the same behavior--the <literal>-I</literal>
+        directories are searched first
+        for <literal>#include</literal> files--which
+        gives &SCons; direct control over the list of
+        directories the C preprocessor will search.
+
+        </para>
+        </listitem>
+
+        <listitem>
+        <para>
+
+        Require that everyone working with compilation from
+        repositories check out and work on entire directories of files,
+        not individual files.
+        (If you use local wrapper scripts around
+        your source code control system's command,
+        you could add logic to enforce this restriction there.
+
+        </para>
+        </listitem>
+
+      </orderedlist>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Finding the &SConstruct; file in repositories</title>
+
+    <para>
+
+    &SCons; will also search in repositories
+    for the &SConstruct; file and any specified &SConscript; files.
+    This poses a problem, though:  how can &SCons; search a
+    repository tree for an &SConstruct; file
+    if the &SConstruct; file itself contains the information
+    about the pathname of the repository?
+    To solve this problem, &SCons; allows you
+    to specify repository directories
+    on the command line using the <literal>-Y</literal> option:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q -Y /usr/repository1 -Y /usr/repository2</userinput>
+    </screen>
+
+    <para>
+
+    When looking for source or derived files,
+    &SCons; will first search the repositories
+    specified on the command line,
+    and then search the repositories
+    specified in the &SConstruct; or &SConscript; files.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Finding derived files in repositories</title>
+
+    <para>
+
+    If a repository contains not only source files,
+    but also derived files (such as object files,
+    libraries, or executables), &SCons; will perform
+    its normal MD5 signature calculation to
+    decide if a derived file in a repository is up-to-date,
+    or the derived file must be rebuilt in the local build directory.
+    For the &SCons; signature calculation to work correctly,
+    a repository tree must contain the &sconsign; files
+    that &SCons; uses to keep track of signature information.
+
+    </para>
+
+    <para>
+
+    Usually, this would be done by a build integrator
+    who would run &SCons; in the repository
+    to create all of its derived files and &sconsign; files,
+    or who would run &SCons; in a separate build directory
+    and copy the resulting tree to the desired repository:
+
+    </para>
+
+    <scons_example name="ex4">
+      <file name="SConstruct">
+       env = Environment()
+       env.Program(['hello.c', 'file1.c', 'file2.c'])
+       Repository('/usr/repository1', '/usr/repository2')
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+      <file name="file1.c">
+      int f1() { printf("file1\n"); }
+      </file>
+      <file name="file2.c">
+      int f2() { printf("file2.c\n"); }
+      </file>
+    </scons_example>
+
+    <scons_output example="ex4">
+      <scons_output_command>cd /usr/repository1</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+    
+    (Note that this is safe even if the &SConstruct; file
+    lists <filename>/usr/repository1</filename> as a repository,
+    because &SCons; will remove the current build directory
+    from its repository list for that invocation.)
+
+    </para>
+
+    <para>
+
+    Now, with the repository populated,
+    we only need to create the one local source file
+    we're interested in working with at the moment,
+    and use the <literal>-Y</literal> option to
+    tell &SCons; to fetch any other files it needs
+    from the repository:
+
+    </para>
+
+    <!--
+    <scons_output example="ex4">
+      <scons_output_command>cd $HOME/build</scons_output_command>
+      <scons_output_command>edit hello.c</scons_output_command>
+      <scons_output_command>scons -Q -Y __ROOT__/usr/repository1</scons_output_command>
+    </scons_output>
+    -->
+    <screen>
+      % <userinput>cd $HOME/build</userinput>
+      % <userinput>edit hello.c</userinput>
+      % <userinput>scons -Q -Y /usr/repository1</userinput>
+      cc -c -o hello.o hello.c
+      cc -o hello hello.o /usr/repository1/file1.o /usr/repository1/file2.o
+    </screen>
+
+    <para>
+
+    Notice that &SCons; realizes that it does not need to
+    rebuild local copies <filename>file1.o</filename> and <filename>file2.o</filename> files,
+    but instead uses the already-compiled files
+    from the repository.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Guaranteeing local copies of files</title>
+
+    <para>
+
+    If the repository tree contains the complete results of a build,
+    and we try to build from the repository
+    without any files in our local tree,
+    something moderately surprising happens:
+
+    </para>
+
+    <screen>
+      % <userinput>mkdir $HOME/build2</userinput>
+      % <userinput>cd $HOME/build2</userinput>
+      % <userinput>scons -Q -Y /usr/all/repository hello</userinput>
+      scons: `hello' is up-to-date.
+    </screen>
+
+    <para>
+
+    Why does &SCons; say that the &hello; program
+    is up-to-date when there is no &hello; program
+    in the local build directory?
+    Because the repository (not the local directory)
+    contains the up-to-date &hello; program,
+    and &SCons; correctly determines that nothing
+    needs to be done to rebuild that
+    up-to-date copy of the file.
+
+    </para>
+
+    <para>
+
+    There are, however, many times when you want to ensure that a
+    local copy of a file always exists.
+    A packaging or testing script, for example,
+    may assume that certain generated files exist locally.
+    To tell &SCons; to make a copy of any up-to-date repository
+    file in the local build directory,
+    use the &Local; function:
+
+    </para>
+
+    <scons_example name="ex5">
+      <file name="SConstruct" printme="1">
+       env = Environment()
+       hello = env.Program('hello.c')
+       Local(hello)
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    If we then run the same command,
+    &SCons; will make a local copy of the program
+    from the repository copy,
+    and tell you that it is doing so:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Y /usr/all/repository hello</userinput>
+      Local copy of hello from /usr/all/repository/hello
+      scons: `hello' is up-to-date.
+    </screen>
+
+    <para>
+
+    (Notice that, because the act of making the local copy
+    is not considered a "build" of the &hello; file,
+    &SCons; still reports that it is up-to-date.)
+
+    </para>
+
+  </section>
diff --git a/doc/user/repositories.xml b/doc/user/repositories.xml
new file mode 100644
index 0000000..7d955c3
--- /dev/null
+++ b/doc/user/repositories.xml
@@ -0,0 +1,595 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  Often, a software project will have
+  one or more central repositories,
+  directory trees that contain
+  source code, or derived files, or both.
+  You can eliminate additional unnecessary
+  rebuilds of files by having &SCons;
+  use files from one or more code repositories
+  to build files in your local build tree.
+
+  </para>
+
+  <section>
+  <title>The &Repository; Method</title>
+
+ <!--
+
+ The repository directories specified may contain source files, derived files
+ (objects, libraries and executables), or both.  If there is no local file
+ (source or derived) under the directory in which Cons is executed, then the
+ first copy of a same-named file found under a repository directory will be
+ used to build any local derived files.
+
+ -->
+
+    <para>
+
+    It's often useful to allow multiple programmers working
+    on a project to build software from
+    source files and/or derived files that
+    are stored in a centrally-accessible repository,
+    a directory copy of the source code tree.
+    (Note that this is not the sort of repository
+    maintained by a source code management system
+    like BitKeeper, CVS, or Subversion.)
+    <!--
+    For information about using &SCons;
+    with these systems, see the section,
+    "Fetching Files From Source Code Management Systems,"
+    below.)
+    -->
+    You use the &Repository; method
+    to tell &SCons; to search one or more
+    central code repositories (in order)
+    for any source files and derived files
+    that are not present in the local build tree:
+
+    </para>
+
+    <programlisting>
+       env = Environment()
+       env.Program('hello.c')
+       Repository('/usr/repository1', '/usr/repository2')
+    </programlisting>
+
+    <para>
+
+    Multiple calls to the &Repository; method
+    will simply add repositories to the global list
+    that &SCons; maintains,
+    with the exception that &SCons; will automatically eliminate
+    the current directory and any non-existent
+    directories from the list.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Finding source files in repositories</title>
+
+    <para>
+
+    The above example
+    specifies that &SCons;
+    will first search for files under
+    the <filename>/usr/repository1</filename> tree
+    and next under the <filename>/usr/repository2</filename> tree.
+    &SCons; expects that any files it searches
+    for will be found in the same position
+    relative to the top-level directory.
+    In the above example, if the &hello_c; file is not
+    found in the local build tree,
+    &SCons; will search first for
+    a <filename>/usr/repository1/hello.c</filename> file
+    and then for a <filename>/usr/repository2/hello.c</filename> file
+    to use in its place.
+
+    </para>
+
+    <para>
+
+    So given the &SConstruct; file above,
+    if the &hello_c; file exists in the local
+    build directory,
+    &SCons; will rebuild the &hello; program
+    as normal:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+    </screen>
+
+    <para>
+
+    If, however, there is no local &hello_c; file,
+    but one exists in <filename>/usr/repository1</filename>,
+    &SCons; will recompile the &hello; program
+    from the source file it finds in the repository:
+
+    </para>
+
+    
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c /usr/repository1/hello.c
+      cc -o hello hello.o
+    </screen>
+
+    <para>
+
+    And similarly, if there is no local &hello_c; file
+    and no <filename>/usr/repository1/hello.c</filename>,
+    but one exists in <filename>/usr/repository2</filename>:
+
+    </para>
+
+    
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c /usr/repository2/hello.c
+      cc -o hello hello.o
+    </screen>
+
+    <para>
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Finding <literal>#include</literal> files in repositories</title>
+
+    <para>
+
+    We've already seen that SCons will scan the contents of
+    a source file for <literal>#include</literal> file names
+    and realize that targets built from that source file
+    also depend on the <literal>#include</literal> file(s).
+    For each directory in the &cv-link-CPPPATH; list,
+    &SCons; will actually search the corresponding directories
+    in any repository trees and establish the
+    correct dependencies on any
+    <literal>#include</literal> files that it finds
+    in repository directory.
+
+    </para>
+
+    <para>
+
+    Unless the C compiler also knows about these directories
+    in the repository trees, though,
+    it will be unable to find the <literal>#include</literal> files.
+    If, for example, the &hello_c; file in
+    our previous example includes the &hello;.h;
+    in its current directory,
+    and the &hello;.h; only exists in the repository:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c hello.c
+      hello.c:1: hello.h: No such file or directory
+    </screen>
+
+    <para>
+
+    In order to inform the C compiler about the repositories,
+    &SCons; will add appropriate
+    <literal>-I</literal> flags to the compilation commands
+    for each directory in the &cv-CPPPATH; list.
+    So if we add the current directory to the
+    construction environment &cv-CPPPATH; like so:
+
+    </para>
+
+    <programlisting>
+       env = Environment(CPPPATH = ['.'])
+       env.Program('hello.c')
+       Repository('/usr/repository1')
+    </programlisting>
+
+    <para>
+
+    Then re-executing &SCons; yields:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c -I. -I/usr/repository1 hello.c
+      cc -o hello hello.o
+    </screen>
+
+    <para>
+
+    The order of the <literal>-I</literal> options replicates,
+    for the C preprocessor,
+    the same repository-directory search path
+    that &SCons; uses for its own dependency analysis.
+    If there are multiple repositories and multiple &cv-CPPPATH;
+    directories, &SCons; will add the repository directories
+    to the beginning of each &cv-CPPPATH; directory,
+    rapidly multiplying the number of <literal>-I</literal> flags.
+    If, for example, the &cv-CPPPATH; contains three directories
+    (and shorter repository path names!):
+
+    </para>
+
+    <programlisting>
+       env = Environment(CPPPATH = ['dir1', 'dir2', 'dir3'])
+       env.Program('hello.c')
+       Repository('/r1', '/r2')
+    </programlisting>
+
+    <para>
+
+    Then we'll end up with nine <literal>-I</literal> options
+    on the command line,
+    three (for each of the &cv-CPPPATH; directories)
+    times three (for the local directory plus the two repositories):
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o hello.o -c -Idir1 -I/r1/dir1 -I/r2/dir1 -Idir2 -I/r1/dir2 -I/r2/dir2 -Idir3 -I/r1/dir3 -I/r2/dir3 hello.c
+      cc -o hello hello.o
+    </screen>
+
+<!--
+
+Cons classic did the following, does SCons?
+
+In order to shorten the command lines as much as possible, Cons will
+remove C<-I> flags for any directories, locally or in the repositories,
+which do not actually exist.  (Note that the C<-I> flags are not included
+in the MD5 signature calculation for the target file, so the target will
+not be recompiled if the compilation command changes due to a directory
+coming into existence.)
+
+-->
+
+    <section>
+    <title>Limitations on <literal>#include</literal> files in repositories</title>
+
+      <para>
+
+      &SCons; relies on the C compiler's
+      <literal>-I</literal> options to control the order in which
+      the preprocessor will search the repository directories
+      for <literal>#include</literal> files.
+      This causes a problem, however, with how the C preprocessor
+      handles <literal>#include</literal> lines with
+      the file name included in double-quotes.
+
+      </para>
+
+      <para>
+
+      As we've seen,
+      &SCons; will compile the &hello_c; file from
+      the repository if it doesn't exist in
+      the local directory.
+      If, however, the &hello_c; file in the repository contains
+      a <literal>#include</literal> line with the file name in
+      double quotes:
+
+      </para>
+
+      <programlisting>
+        #include "hello.h"
+        int
+        main(int argc, char *argv[])
+        {
+            printf(HELLO_MESSAGE);
+            return (0);
+        }
+      </programlisting>
+
+      <para>
+
+      Then the C preprocessor will <emphasis>always</emphasis>
+      use a &hello_h; file from the repository directory first,
+      even if there is a &hello_h; file in the local directory,
+      despite the fact that the command line specifies
+      <literal>-I</literal> as the first option:
+
+      </para>
+
+      
+
+      <screen>
+        % <userinput>scons -Q</userinput>
+        cc -o hello.o -c -I. -I/usr/repository1 /usr/repository1/hello.c
+        cc -o hello hello.o
+      </screen>
+
+      <para>
+
+      This behavior of the C preprocessor--always search
+      for a <literal>#include</literal> file in double-quotes
+      first in the same directory as the source file,
+      and only then search the <literal>-I</literal>--can
+      not, in general, be changed.
+      In other words, it's a limitation
+      that must be lived with if you want to use
+      code repositories in this way.
+      There are three ways you can possibly
+      work around this C preprocessor behavior:
+
+      </para>
+
+      <orderedlist>
+
+        <listitem>
+        <para>
+
+        Some modern versions of C compilers do have an option
+        to disable or control this behavior.
+        If so, add that option to &cv-link-CFLAGS;
+        (or &cv-link-CXXFLAGS; or both) in your construction environment(s).
+        Make sure the option is used for all construction
+        environments that use C preprocessing!
+
+        </para>
+        </listitem>
+
+        <listitem>
+        <para>
+
+        Change all occurrences of <literal>#include "file.h"</literal>
+        to <literal>#include &lt;file.h&gt;</literal>.
+        Use of <literal>#include</literal> with angle brackets
+        does not have the same behavior--the <literal>-I</literal>
+        directories are searched first
+        for <literal>#include</literal> files--which
+        gives &SCons; direct control over the list of
+        directories the C preprocessor will search.
+
+        </para>
+        </listitem>
+
+        <listitem>
+        <para>
+
+        Require that everyone working with compilation from
+        repositories check out and work on entire directories of files,
+        not individual files.
+        (If you use local wrapper scripts around
+        your source code control system's command,
+        you could add logic to enforce this restriction there.
+
+        </para>
+        </listitem>
+
+      </orderedlist>
+
+    </section>
+
+  </section>
+
+  <section>
+  <title>Finding the &SConstruct; file in repositories</title>
+
+    <para>
+
+    &SCons; will also search in repositories
+    for the &SConstruct; file and any specified &SConscript; files.
+    This poses a problem, though:  how can &SCons; search a
+    repository tree for an &SConstruct; file
+    if the &SConstruct; file itself contains the information
+    about the pathname of the repository?
+    To solve this problem, &SCons; allows you
+    to specify repository directories
+    on the command line using the <literal>-Y</literal> option:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q -Y /usr/repository1 -Y /usr/repository2</userinput>
+    </screen>
+
+    <para>
+
+    When looking for source or derived files,
+    &SCons; will first search the repositories
+    specified on the command line,
+    and then search the repositories
+    specified in the &SConstruct; or &SConscript; files.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Finding derived files in repositories</title>
+
+    <para>
+
+    If a repository contains not only source files,
+    but also derived files (such as object files,
+    libraries, or executables), &SCons; will perform
+    its normal MD5 signature calculation to
+    decide if a derived file in a repository is up-to-date,
+    or the derived file must be rebuilt in the local build directory.
+    For the &SCons; signature calculation to work correctly,
+    a repository tree must contain the &sconsign; files
+    that &SCons; uses to keep track of signature information.
+
+    </para>
+
+    <para>
+
+    Usually, this would be done by a build integrator
+    who would run &SCons; in the repository
+    to create all of its derived files and &sconsign; files,
+    or who would run &SCons; in a separate build directory
+    and copy the resulting tree to the desired repository:
+
+    </para>
+
+    
+
+    <screen>
+      % <userinput>cd /usr/repository1</userinput>
+      % <userinput>scons -Q</userinput>
+      cc -o file1.o -c file1.c
+      cc -o file2.o -c file2.c
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o file1.o file2.o
+    </screen>
+
+    <para>
+    
+    (Note that this is safe even if the &SConstruct; file
+    lists <filename>/usr/repository1</filename> as a repository,
+    because &SCons; will remove the current build directory
+    from its repository list for that invocation.)
+
+    </para>
+
+    <para>
+
+    Now, with the repository populated,
+    we only need to create the one local source file
+    we're interested in working with at the moment,
+    and use the <literal>-Y</literal> option to
+    tell &SCons; to fetch any other files it needs
+    from the repository:
+
+    </para>
+
+    <!--
+    <scons_output example="ex4">
+      <scons_output_command>cd $HOME/build</scons_output_command>
+      <scons_output_command>edit hello.c</scons_output_command>
+      <scons_output_command>scons -Q -Y __ROOT__/usr/repository1</scons_output_command>
+    </scons_output>
+    -->
+    <screen>
+      % <userinput>cd $HOME/build</userinput>
+      % <userinput>edit hello.c</userinput>
+      % <userinput>scons -Q -Y /usr/repository1</userinput>
+      cc -c -o hello.o hello.c
+      cc -o hello hello.o /usr/repository1/file1.o /usr/repository1/file2.o
+    </screen>
+
+    <para>
+
+    Notice that &SCons; realizes that it does not need to
+    rebuild local copies <filename>file1.o</filename> and <filename>file2.o</filename> files,
+    but instead uses the already-compiled files
+    from the repository.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Guaranteeing local copies of files</title>
+
+    <para>
+
+    If the repository tree contains the complete results of a build,
+    and we try to build from the repository
+    without any files in our local tree,
+    something moderately surprising happens:
+
+    </para>
+
+    <screen>
+      % <userinput>mkdir $HOME/build2</userinput>
+      % <userinput>cd $HOME/build2</userinput>
+      % <userinput>scons -Q -Y /usr/all/repository hello</userinput>
+      scons: `hello' is up-to-date.
+    </screen>
+
+    <para>
+
+    Why does &SCons; say that the &hello; program
+    is up-to-date when there is no &hello; program
+    in the local build directory?
+    Because the repository (not the local directory)
+    contains the up-to-date &hello; program,
+    and &SCons; correctly determines that nothing
+    needs to be done to rebuild that
+    up-to-date copy of the file.
+
+    </para>
+
+    <para>
+
+    There are, however, many times when you want to ensure that a
+    local copy of a file always exists.
+    A packaging or testing script, for example,
+    may assume that certain generated files exist locally.
+    To tell &SCons; to make a copy of any up-to-date repository
+    file in the local build directory,
+    use the &Local; function:
+
+    </para>
+
+    <programlisting>
+       env = Environment()
+       hello = env.Program('hello.c')
+       Local(hello)
+    </programlisting>
+
+    <para>
+
+    If we then run the same command,
+    &SCons; will make a local copy of the program
+    from the repository copy,
+    and tell you that it is doing so:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Y /usr/all/repository hello</userinput>
+      Local copy of hello from /usr/all/repository/hello
+      scons: `hello' is up-to-date.
+    </screen>
+
+    <para>
+
+    (Notice that, because the act of making the local copy
+    is not considered a "build" of the &hello; file,
+    &SCons; still reports that it is up-to-date.)
+
+    </para>
+
+  </section>
diff --git a/doc/user/run.in b/doc/user/run.in
new file mode 100644
index 0000000..946a7ed
--- /dev/null
+++ b/doc/user/run.in
@@ -0,0 +1,375 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 Invoking Cons
+
+The C<cons> command is usually invoked from the root of the build tree. A
+F<Construct> file must exist in that directory. If the C<-f> argument is
+used, then an alternate F<Construct> file may be used (and, possibly, an
+alternate root, since C<cons> will cd to F<Construct> file's containing
+directory).
+
+If C<cons> is invoked from a child of the root of the build tree with
+the C<-t> argument, it will walk up the directory hierarchy looking for a
+F<Construct> file.  (An alternate name may still be specified with C<-f>.)
+The targets supplied on the command line will be modified to be relative
+to the discovered F<Construct> file.  For example, from a directory
+containing a top-level F<Construct> file, the following invocation:
+
+  % cd libfoo/subdir
+  % cons -t target
+
+is exactly equivalent to:
+
+  % cons libfoo/subdir/target
+
+If there are any C<Default> targets specified in the directory hierarchy's
+F<Construct> or F<Conscript> files, only the default targets at or below
+the directory from which C<cons -t> was invoked will be built.
+
+The command is invoked as follows:
+
+  cons <arguments> ,  <construct-args>
+
+where I<arguments> can be any of the following, in any order:
+
+=over 10
+
+=item I<target>
+
+Build the specified target. If I<target> is a directory, then recursively
+build everything within that directory.
+
+=item I<+pattern>
+
+Limit the F<Conscript> files considered to just those that match I<pattern>,
+which is a Perl regular expression. Multiple C<+> arguments are accepted.
+
+=item I<name>=<val>
+
+Sets I<name> to value I<val> in the C<ARG> hash passed to the top-level
+F<Construct> file.
+
+=item C<-cc>
+
+Show command that would have been executed, when retrieving from cache. No
+indication that the file has been retrieved is given; this is useful for
+generating build logs that can be compared with real build logs.
+
+=item C<-cd>
+
+Disable all caching. Do not retrieve from cache nor flush to cache.
+
+=item C<-cr>
+
+Build dependencies in random order. This is useful when building multiple
+similar trees with caching enabled.
+
+=item C<-cs>
+
+Synchronize existing build targets that are found to be up-to-date with
+cache. This is useful if caching has been disabled with -cc or just recently
+enabled with UseCache.
+
+=item C<-d>
+
+Enable dependency debugging.
+
+=item C<-f> <file>
+
+Use the specified file instead of F<Construct> (but first change to
+containing directory of I<file>).
+
+=item C<-h>
+
+Show a help message local to the current build if one such is defined, and
+exit.
+
+=item C<-k>
+
+Keep going as far as possible after errors.
+
+=item C<-o> <file>
+
+Read override file I<file>.
+
+=item C<-p>
+
+Show construction products in specified trees. No build is attempted.
+
+=item C<-pa>
+
+Show construction products and associated actions. No build is attempted.
+
+=item C<-pw>
+
+Show products and where they are defined. No build is attempted.
+
+=item C<-q>
+
+Make the build quiet.  Multiple C<-q> options may be specified.
+
+A single C<-q> options suppress messages about Installing and Removing
+targets.
+
+Two C<-q> options suppress build command lines and target up-to-date
+messages.
+
+=item C<-r>
+
+Remove construction products associated with <targets>. No build is
+attempted.
+
+=item C<-R> <repos>
+
+Search for files in I<repos>.  Multiple B<-R> I<repos> directories are
+searched in the order specified.
+
+=item C<-S> <pkg>
+
+Use the sig::<pkg> package to calculate.  Supported <pkg> values
+include "md5" for MD5 signature calculation and "md5::debug" for debug
+information about MD5 signature calculation.
+
+If the specified package ends in <::debug>, signature debug information
+will be printed to the file name specified in the C<CONS_SIG_DEBUG>
+environment variable, or to standard output if the environment variable
+is not set.
+
+=item C<-t>
+
+Traverse up the directory hierarchy looking for a F<Construct> file,
+if none exists in the current directory.  Targets will be modified to
+be relative to the F<Construct> file.
+
+Internally, C<cons> will change its working directory to the directory
+which contains the top-level F<Construct> file and report:
+
+  cons: Entering directory `top-level-directory'
+
+This message indicates to an invoking editor (such as emacs) or build
+environment that Cons will now report all file names relative to the
+top-level directory.  This message can not be suppressed with the C<-q>
+option.
+
+=item C<-v>
+
+Show C<cons> version and continue processing.
+
+=item C<-V>
+
+Show C<cons> version and exit.
+
+=item C<-wf> <file>
+
+Write all filenames considered into I<file>.
+
+=item C<-x>
+
+Show a help message similar to this one, and exit.
+
+=back
+
+And I<construct-args> can be any arguments that you wish to process in the
+F<Construct> file. Note that there should be a B<-,-> separating the arguments
+to cons and the arguments that you wish to process in the F<Construct> file.
+
+Processing of I<construct-args> can be done by any standard package like
+B<Getopt> or its variants, or any user defined package. B<cons> will pass in
+the I<construct-args> as B<@ARGV> and will not attempt to interpret anything
+after the B<-,->.
+
+  % cons -R /usr/local/repository -d os=solaris +driver -,- -c test -f DEBUG
+
+would pass the following to cons
+
+  -R /usr/local/repository -d os=solaris +driver
+
+and the following, to the top level F<Construct> file as B<@ARGV>
+
+  -c test -f DEBUG
+
+Note that C<cons -r .> is equivalent to a full recursive C<make clean>,
+but requires no support in the F<Construct> file or any F<Conscript>
+files. This is most useful if you are compiling files into source
+directories (if you separate the F<build> and F<export> directories,
+then you can just remove the directories).
+
+The options C<-p>, C<-pa>, and C<-pw> are extremely useful for use as an aid
+in reading scripts or debugging them. If you want to know what script
+installs F<export/include/foo.h>, for example, just type:
+
+  % cons -pw export/include/foo.h
+
+=head1 Selective builds
+
+Cons provides two methods for reducing the size of given build. The first is
+by specifying targets on the command line, and the second is a method for
+pruning the build tree. We'll consider target specification first.
+
+
+=head2 Selective targeting
+
+Like make, Cons allows the specification of ``targets'' on the command
+line. Cons targets may be either files or directories. When a directory is
+specified, this is simply a short-hand notation for every derivable
+product-,-that Cons knows about-,-in the specified directory and below. For
+example:
+
+  % cons build/hello/hello.o
+
+means build F<hello.o> and everything that F<hello.o> might need. This is
+from a previous version of the B<Hello, World!> program in which F<hello.o>
+depended upon F<export/include/world.h>. If that file is not up-to-date
+(because someone modified F<src/world/world.h)>, then it will be rebuilt,
+even though it is in a directory remote from F<build/hello>.
+
+In this example:
+
+  % cons build
+
+Everything in the F<build> directory is built, if necessary. Again, this may
+cause more files to be built. In particular, both F<export/include/world.h>
+and F<export/lib/libworld.a> are required by the F<build/hello> directory,
+and so they will be built if they are out-of-date.
+
+If we do, instead:
+
+  % cons export
+
+then only the files that should be installed in the export directory will be
+rebuilt, if necessary, and then installed there. Note that C<cons build>
+might build files that C<cons export> doesn't build, and vice-versa.
+
+
+=head1 Build Pruning
+
+In conjunction with target selection, B<build pruning> can be used to reduce
+the scope of the build. In the previous peAcH and baNaNa example, we have
+already seen how script-driven build pruning can be used to make only half
+of the potential build available for any given invocation of C<cons>. Cons
+also provides, as a convenience, a command line convention that allows you
+to specify which F<Conscript> files actually get ``built''-,-that is,
+incorporated into the build tree. For example:
+
+  % cons build +world
+
+The C<+> argument introduces a Perl regular expression. This must, of
+course, be quoted at the shell level if there are any shell meta-characters
+within the expression. The expression is matched against each F<Conscript>
+file which has been mentioned in a C<Build> statement, and only those
+scripts with matching names are actually incorporated into the build
+tree. Multiple such arguments are allowed, in which case a match against any
+of them is sufficient to cause a script to be included.
+
+In the example, above, the F<hello> program will not be built, since Cons
+will have no knowledge of the script F<hello/Conscript>. The F<libworld.a>
+archive will be built, however, if need be.
+
+There are a couple of uses for build pruning via the command line. Perhaps
+the most useful is the ability to make local changes, and then, with
+sufficient knowledge of the consequences of those changes, restrict the size
+of the build tree in order to speed up the rebuild time. A second use for
+build pruning is to actively prevent the recompilation of certain files that
+you know will recompile due to, for example, a modified header file. You may
+know that either the changes to the header file are immaterial, or that the
+changes may be safely ignored for most of the tree, for testing
+purposes.With Cons, the view is that it is pragmatic to admit this type of
+behavior, with the understanding that on the next full build everything that
+needs to be rebuilt will be. There is no equivalent to a ``make touch''
+command, to mark files as permanently up-to-date. So any risk that is
+incurred by build pruning is mitigated. For release quality work, obviously,
+we recommend that you do not use build pruning (it's perfectly OK to use
+during integration, however, for checking compilation, etc. Just be sure to
+do an unconstrained build before committing the integration).
+
+-->
+
+  <para>
+
+    XXX
+
+  </para>
+
+  <section>
+  <title>Command-Line Options</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Getting at Command-Line Arguments</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Selective Builds</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Build Pruning</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+  </section>
+
+  -->
+
+  <section>
+  <title>Overriding Construction Variables</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+  </section>
diff --git a/doc/user/run.xml b/doc/user/run.xml
new file mode 100644
index 0000000..946a7ed
--- /dev/null
+++ b/doc/user/run.xml
@@ -0,0 +1,375 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 Invoking Cons
+
+The C<cons> command is usually invoked from the root of the build tree. A
+F<Construct> file must exist in that directory. If the C<-f> argument is
+used, then an alternate F<Construct> file may be used (and, possibly, an
+alternate root, since C<cons> will cd to F<Construct> file's containing
+directory).
+
+If C<cons> is invoked from a child of the root of the build tree with
+the C<-t> argument, it will walk up the directory hierarchy looking for a
+F<Construct> file.  (An alternate name may still be specified with C<-f>.)
+The targets supplied on the command line will be modified to be relative
+to the discovered F<Construct> file.  For example, from a directory
+containing a top-level F<Construct> file, the following invocation:
+
+  % cd libfoo/subdir
+  % cons -t target
+
+is exactly equivalent to:
+
+  % cons libfoo/subdir/target
+
+If there are any C<Default> targets specified in the directory hierarchy's
+F<Construct> or F<Conscript> files, only the default targets at or below
+the directory from which C<cons -t> was invoked will be built.
+
+The command is invoked as follows:
+
+  cons <arguments> ,  <construct-args>
+
+where I<arguments> can be any of the following, in any order:
+
+=over 10
+
+=item I<target>
+
+Build the specified target. If I<target> is a directory, then recursively
+build everything within that directory.
+
+=item I<+pattern>
+
+Limit the F<Conscript> files considered to just those that match I<pattern>,
+which is a Perl regular expression. Multiple C<+> arguments are accepted.
+
+=item I<name>=<val>
+
+Sets I<name> to value I<val> in the C<ARG> hash passed to the top-level
+F<Construct> file.
+
+=item C<-cc>
+
+Show command that would have been executed, when retrieving from cache. No
+indication that the file has been retrieved is given; this is useful for
+generating build logs that can be compared with real build logs.
+
+=item C<-cd>
+
+Disable all caching. Do not retrieve from cache nor flush to cache.
+
+=item C<-cr>
+
+Build dependencies in random order. This is useful when building multiple
+similar trees with caching enabled.
+
+=item C<-cs>
+
+Synchronize existing build targets that are found to be up-to-date with
+cache. This is useful if caching has been disabled with -cc or just recently
+enabled with UseCache.
+
+=item C<-d>
+
+Enable dependency debugging.
+
+=item C<-f> <file>
+
+Use the specified file instead of F<Construct> (but first change to
+containing directory of I<file>).
+
+=item C<-h>
+
+Show a help message local to the current build if one such is defined, and
+exit.
+
+=item C<-k>
+
+Keep going as far as possible after errors.
+
+=item C<-o> <file>
+
+Read override file I<file>.
+
+=item C<-p>
+
+Show construction products in specified trees. No build is attempted.
+
+=item C<-pa>
+
+Show construction products and associated actions. No build is attempted.
+
+=item C<-pw>
+
+Show products and where they are defined. No build is attempted.
+
+=item C<-q>
+
+Make the build quiet.  Multiple C<-q> options may be specified.
+
+A single C<-q> options suppress messages about Installing and Removing
+targets.
+
+Two C<-q> options suppress build command lines and target up-to-date
+messages.
+
+=item C<-r>
+
+Remove construction products associated with <targets>. No build is
+attempted.
+
+=item C<-R> <repos>
+
+Search for files in I<repos>.  Multiple B<-R> I<repos> directories are
+searched in the order specified.
+
+=item C<-S> <pkg>
+
+Use the sig::<pkg> package to calculate.  Supported <pkg> values
+include "md5" for MD5 signature calculation and "md5::debug" for debug
+information about MD5 signature calculation.
+
+If the specified package ends in <::debug>, signature debug information
+will be printed to the file name specified in the C<CONS_SIG_DEBUG>
+environment variable, or to standard output if the environment variable
+is not set.
+
+=item C<-t>
+
+Traverse up the directory hierarchy looking for a F<Construct> file,
+if none exists in the current directory.  Targets will be modified to
+be relative to the F<Construct> file.
+
+Internally, C<cons> will change its working directory to the directory
+which contains the top-level F<Construct> file and report:
+
+  cons: Entering directory `top-level-directory'
+
+This message indicates to an invoking editor (such as emacs) or build
+environment that Cons will now report all file names relative to the
+top-level directory.  This message can not be suppressed with the C<-q>
+option.
+
+=item C<-v>
+
+Show C<cons> version and continue processing.
+
+=item C<-V>
+
+Show C<cons> version and exit.
+
+=item C<-wf> <file>
+
+Write all filenames considered into I<file>.
+
+=item C<-x>
+
+Show a help message similar to this one, and exit.
+
+=back
+
+And I<construct-args> can be any arguments that you wish to process in the
+F<Construct> file. Note that there should be a B<-,-> separating the arguments
+to cons and the arguments that you wish to process in the F<Construct> file.
+
+Processing of I<construct-args> can be done by any standard package like
+B<Getopt> or its variants, or any user defined package. B<cons> will pass in
+the I<construct-args> as B<@ARGV> and will not attempt to interpret anything
+after the B<-,->.
+
+  % cons -R /usr/local/repository -d os=solaris +driver -,- -c test -f DEBUG
+
+would pass the following to cons
+
+  -R /usr/local/repository -d os=solaris +driver
+
+and the following, to the top level F<Construct> file as B<@ARGV>
+
+  -c test -f DEBUG
+
+Note that C<cons -r .> is equivalent to a full recursive C<make clean>,
+but requires no support in the F<Construct> file or any F<Conscript>
+files. This is most useful if you are compiling files into source
+directories (if you separate the F<build> and F<export> directories,
+then you can just remove the directories).
+
+The options C<-p>, C<-pa>, and C<-pw> are extremely useful for use as an aid
+in reading scripts or debugging them. If you want to know what script
+installs F<export/include/foo.h>, for example, just type:
+
+  % cons -pw export/include/foo.h
+
+=head1 Selective builds
+
+Cons provides two methods for reducing the size of given build. The first is
+by specifying targets on the command line, and the second is a method for
+pruning the build tree. We'll consider target specification first.
+
+
+=head2 Selective targeting
+
+Like make, Cons allows the specification of ``targets'' on the command
+line. Cons targets may be either files or directories. When a directory is
+specified, this is simply a short-hand notation for every derivable
+product-,-that Cons knows about-,-in the specified directory and below. For
+example:
+
+  % cons build/hello/hello.o
+
+means build F<hello.o> and everything that F<hello.o> might need. This is
+from a previous version of the B<Hello, World!> program in which F<hello.o>
+depended upon F<export/include/world.h>. If that file is not up-to-date
+(because someone modified F<src/world/world.h)>, then it will be rebuilt,
+even though it is in a directory remote from F<build/hello>.
+
+In this example:
+
+  % cons build
+
+Everything in the F<build> directory is built, if necessary. Again, this may
+cause more files to be built. In particular, both F<export/include/world.h>
+and F<export/lib/libworld.a> are required by the F<build/hello> directory,
+and so they will be built if they are out-of-date.
+
+If we do, instead:
+
+  % cons export
+
+then only the files that should be installed in the export directory will be
+rebuilt, if necessary, and then installed there. Note that C<cons build>
+might build files that C<cons export> doesn't build, and vice-versa.
+
+
+=head1 Build Pruning
+
+In conjunction with target selection, B<build pruning> can be used to reduce
+the scope of the build. In the previous peAcH and baNaNa example, we have
+already seen how script-driven build pruning can be used to make only half
+of the potential build available for any given invocation of C<cons>. Cons
+also provides, as a convenience, a command line convention that allows you
+to specify which F<Conscript> files actually get ``built''-,-that is,
+incorporated into the build tree. For example:
+
+  % cons build +world
+
+The C<+> argument introduces a Perl regular expression. This must, of
+course, be quoted at the shell level if there are any shell meta-characters
+within the expression. The expression is matched against each F<Conscript>
+file which has been mentioned in a C<Build> statement, and only those
+scripts with matching names are actually incorporated into the build
+tree. Multiple such arguments are allowed, in which case a match against any
+of them is sufficient to cause a script to be included.
+
+In the example, above, the F<hello> program will not be built, since Cons
+will have no knowledge of the script F<hello/Conscript>. The F<libworld.a>
+archive will be built, however, if need be.
+
+There are a couple of uses for build pruning via the command line. Perhaps
+the most useful is the ability to make local changes, and then, with
+sufficient knowledge of the consequences of those changes, restrict the size
+of the build tree in order to speed up the rebuild time. A second use for
+build pruning is to actively prevent the recompilation of certain files that
+you know will recompile due to, for example, a modified header file. You may
+know that either the changes to the header file are immaterial, or that the
+changes may be safely ignored for most of the tree, for testing
+purposes.With Cons, the view is that it is pragmatic to admit this type of
+behavior, with the understanding that on the next full build everything that
+needs to be rebuilt will be. There is no equivalent to a ``make touch''
+command, to mark files as permanently up-to-date. So any risk that is
+incurred by build pruning is mitigated. For release quality work, obviously,
+we recommend that you do not use build pruning (it's perfectly OK to use
+during integration, however, for checking compilation, etc. Just be sure to
+do an unconstrained build before committing the integration).
+
+-->
+
+  <para>
+
+    XXX
+
+  </para>
+
+  <section>
+  <title>Command-Line Options</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Getting at Command-Line Arguments</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Selective Builds</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Build Pruning</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+  </section>
+
+  -->
+
+  <section>
+  <title>Overriding Construction Variables</title>
+
+    <para>
+
+    XXX
+
+    </para>
+
+  </section>
diff --git a/doc/user/scanners.in b/doc/user/scanners.in
new file mode 100644
index 0000000..8fa36d7
--- /dev/null
+++ b/doc/user/scanners.in
@@ -0,0 +1,331 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 Using and writing dependency scanners
+
+QuickScan allows simple target-independent scanners to be set up for
+source files. Only one QuickScan scanner may be associated with any given
+source file and environment, although the same scanner may (and should)
+be used for multiple files of a given type.
+
+A QuickScan scanner is only ever invoked once for a given source file,
+and it is only invoked if the file is used by some target in the tree
+(i.e., there is a dependency on the source file).
+
+QuickScan is invoked as follows:
+
+  QuickScan CONSENV CODEREF, FILENAME [, PATH]
+
+The subroutine referenced by CODEREF is expected to return a list of
+filenames included directly by FILE. These filenames will, in turn, be
+scanned. The optional PATH argument supplies a lookup path for finding
+FILENAME and/or files returned by the user-supplied subroutine.  The PATH
+may be a reference to an array of lookup-directory names, or a string of
+names separated by the system's separator character (':' on UNIX systems,
+';' on Windows NT).
+
+The subroutine is called once for each line in the file, with $_ set to the
+current line. If the subroutine needs to look at additional lines, or, for
+that matter, the entire file, then it may read them itself, from the
+filehandle SCAN. It may also terminate the loop, if it knows that no further
+include information is available, by closing the filehandle.
+
+Whether or not a lookup path is provided, QuickScan first tries to lookup
+the file relative to the current directory (for the top-level file
+supplied directly to QuickScan), or from the directory containing the
+file which referenced the file. This is not very general, but seems good
+enough, especially if you have the luxury of writing your own utilities
+and can control the use of the search path in a standard way.
+
+Here's a real example, taken from a F<Construct> file here:
+
+  sub cons::SMFgen {
+      my($env, @tables) = @_;
+      foreach $t (@tables) {
+	  $env->QuickScan(sub { /\b\S*?\.smf\b/g }, "$t.smf",
+			  $env->{SMF_INCLUDE_PATH});
+	  $env->Command(["$t.smdb.cc","$t.smdb.h","$t.snmp.cc",
+			 "$t.ami.cc", "$t.http.cc"], "$t.smf",
+			q(smfgen %( %SMF_INCLUDE_OPT %) %<));
+      }
+  }
+
+The subroutine above finds all names of the form <name>.smf in the
+file. It will return the names even if they're found within comments,
+but that's OK (the mechanism is forgiving of extra files; they're just
+ignored on the assumption that the missing file will be noticed when
+the program, in this example, smfgen, is actually invoked).
+
+[NOTE that the form C<$env-E<gt>QuickScan ...>  and C<$env-E<gt>Command
+...> should not be necessary, but, for some reason, is required
+for this particular invocation. This appears to be a bug in Perl or
+a misunderstanding on my part; this invocation style does not always
+appear to be necessary.]
+
+Here is another way to build the same scanner. This one uses an
+explicit code reference, and also (unnecessarily, in this case) reads
+the whole file itself:
+
+  sub myscan {
+      my(@includes);
+      do {
+	  push(@includes, /\b\S*?\.smf\b/g);
+      } while <SCAN>;
+      @includes
+  }
+
+Note that the order of the loop is reversed, with the loop test at the
+end. This is because the first line is already read for you. This scanner
+can be attached to a source file by:
+
+  QuickScan $env \&myscan, "$_.smf";
+
+This final example, which scans a different type of input file, takes
+over the file scanning rather than being called for each input line:
+
+  $env->QuickScan(
+      sub { my(@includes) = ();
+	  do {
+	     push(@includes, $3)
+		 if /^(#include|import)\s+(\")(.+)(\")/ && $3
+	  } while <SCAN>;
+	  @includes
+      },
+      "$idlFileName",
+      "$env->{CPPPATH};$BUILD/ActiveContext/ACSCLientInterfaces"
+  );
+
+-->
+
+  <para>
+
+    &SCons; has built-in scanners that know how to look in
+    C, Fortran and IDL source files for information about
+    other files that targets built from those files depend on--for example,
+    in the case of files that use the C preprocessor,
+    the <filename>.h</filename> files that are specified
+    using <literal>#include</literal> lines in the source.
+    You can use the same mechanisms that &SCons; uses to create
+    its built-in scanners to write scanners of your own for file types
+    that &SCons; does not know how to scan "out of the box."
+
+  </para>
+
+  <section>
+  <title>A Simple Scanner Example</title>
+
+    <para>
+
+      Suppose, for example, that we want to create a simple scanner
+      for <filename>.foo</filename> files.
+      A <filename>.foo</filename> file contains some text that
+      will be processed,
+      and can include other files on lines that begin
+      with <literal>include</literal>
+      followed by a file name:
+
+    </para>
+
+    <programlisting>
+      include filename.foo
+    </programlisting>
+
+    <para>
+
+      Scanning a file will be handled by a Python function
+      that you must supply.
+      Here is a function that will use the Python
+      <filename>re</filename> module
+      to scan for the <literal>include</literal> lines in our example:
+
+    </para>
+
+    <programlisting>
+      import re
+      
+      include_re = re.compile(r'^include\s+(\S+)$', re.M)
+      
+      def kfile_scan(node, env, path, arg):
+          contents = node.get_text_contents()
+          return include_re.findall(contents)
+    </programlisting>
+
+    <para>
+
+      The scanner function must
+      accept the four specified arguments
+      and return a list of implicit dependencies.
+      Presumably, these would be dependencies found
+      from examining the contents of the file,
+      although the function can perform any
+      manipulation at all to generate the list of
+      dependencies.
+
+    </para>
+
+    <variablelist>
+
+      <varlistentry>
+      <term>node</term>
+
+      <listitem>
+      <para>
+
+      An &SCons; node object representing the file being scanned.
+      The path name to the file can be
+      used by converting the node to a string
+      using the <literal>str()</literal> function,
+      or an internal &SCons; <literal>get_text_contents()</literal>
+      object method can be used to fetch the contents.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>env</term>
+
+      <listitem>
+      <para>
+
+      The construction environment in effect for this scan.
+      The scanner function may choose to use construction
+      variables from this environment to affect its behavior.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>path</term>
+
+      <listitem>
+      <para>
+
+      A list of directories that form the search path for included files
+      for this scanner.
+      This is how &SCons; handles the &cv-link-CPPPATH; and &cv-link-LIBPATH;
+      variables.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>arg</term>
+
+      <listitem>
+      <para>
+
+      An optional argument that you can choose to
+      have passed to this scanner function by
+      various scanner instances.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+    </variablelist>
+
+    <para>
+
+    A Scanner object is created using the &Scanner; function,
+    which typically takes an <literal>skeys</literal> argument
+    to associate the type of file suffix with this scanner.
+    The Scanner object must then be associated with the
+    &cv-link-SCANNERS; construction variable of a construction environment,
+    typically by using the &Append; method:
+
+    </para>
+
+    <programlisting>
+       kscan = Scanner(function = kfile_scan,
+                       skeys = ['.k'])
+       env.Append(SCANNERS = kscan)
+    </programlisting>
+
+    <para>
+
+    When we put it all together, it looks like:
+
+    </para>
+
+    <scons_example name="scan">
+      <file name="SConstruct" printme="1">
+        import re
+
+        include_re = re.compile(r'^include\s+(\S+)$', re.M)
+
+        def kfile_scan(node, env, path):
+            contents = node.get_text_contents()
+            includes = include_re.findall(contents)
+            return includes
+
+        kscan = Scanner(function = kfile_scan,
+                        skeys = ['.k'])
+
+        env = Environment(ENV = {'PATH' : '__ROOT__/usr/local/bin'})
+        env.Append(SCANNERS = kscan)
+
+        env.Command('foo', 'foo.k', 'kprocess &lt; $SOURCES &gt; $TARGET')
+      </file>
+      <file name="foo.k">
+      include other_file
+      </file>
+      <file name="other_file">
+      other_file
+      </file>
+      <directory name="__ROOT__/usr"></directory>
+      <directory name="__ROOT__/usr/local"></directory>
+      <directory name="__ROOT__/usr/local/bin"></directory>
+      <file name="__ROOT_/usr/local/bin/kprocess" chmod="755">
+      cat
+      </file>
+    </scons_example>
+
+    <!--
+
+    <para>
+
+      Now if we run &scons;
+      and then re-run it after changing the contents of
+      <filename>other_file</filename>,
+      the <filename>foo</filename>
+      target file will be automatically rebuilt:
+
+    </para>
+
+    <scons_output example="scan">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command output="    [CHANGE THE CONTENTS OF other_file]">edit other_file</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+  </section>
diff --git a/doc/user/scanners.xml b/doc/user/scanners.xml
new file mode 100644
index 0000000..d34b222
--- /dev/null
+++ b/doc/user/scanners.xml
@@ -0,0 +1,317 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 Using and writing dependency scanners
+
+QuickScan allows simple target-independent scanners to be set up for
+source files. Only one QuickScan scanner may be associated with any given
+source file and environment, although the same scanner may (and should)
+be used for multiple files of a given type.
+
+A QuickScan scanner is only ever invoked once for a given source file,
+and it is only invoked if the file is used by some target in the tree
+(i.e., there is a dependency on the source file).
+
+QuickScan is invoked as follows:
+
+  QuickScan CONSENV CODEREF, FILENAME [, PATH]
+
+The subroutine referenced by CODEREF is expected to return a list of
+filenames included directly by FILE. These filenames will, in turn, be
+scanned. The optional PATH argument supplies a lookup path for finding
+FILENAME and/or files returned by the user-supplied subroutine.  The PATH
+may be a reference to an array of lookup-directory names, or a string of
+names separated by the system's separator character (':' on UNIX systems,
+';' on Windows NT).
+
+The subroutine is called once for each line in the file, with $_ set to the
+current line. If the subroutine needs to look at additional lines, or, for
+that matter, the entire file, then it may read them itself, from the
+filehandle SCAN. It may also terminate the loop, if it knows that no further
+include information is available, by closing the filehandle.
+
+Whether or not a lookup path is provided, QuickScan first tries to lookup
+the file relative to the current directory (for the top-level file
+supplied directly to QuickScan), or from the directory containing the
+file which referenced the file. This is not very general, but seems good
+enough, especially if you have the luxury of writing your own utilities
+and can control the use of the search path in a standard way.
+
+Here's a real example, taken from a F<Construct> file here:
+
+  sub cons::SMFgen {
+      my($env, @tables) = @_;
+      foreach $t (@tables) {
+	  $env->QuickScan(sub { /\b\S*?\.smf\b/g }, "$t.smf",
+			  $env->{SMF_INCLUDE_PATH});
+	  $env->Command(["$t.smdb.cc","$t.smdb.h","$t.snmp.cc",
+			 "$t.ami.cc", "$t.http.cc"], "$t.smf",
+			q(smfgen %( %SMF_INCLUDE_OPT %) %<));
+      }
+  }
+
+The subroutine above finds all names of the form <name>.smf in the
+file. It will return the names even if they're found within comments,
+but that's OK (the mechanism is forgiving of extra files; they're just
+ignored on the assumption that the missing file will be noticed when
+the program, in this example, smfgen, is actually invoked).
+
+[NOTE that the form C<$env-E<gt>QuickScan ...>  and C<$env-E<gt>Command
+...> should not be necessary, but, for some reason, is required
+for this particular invocation. This appears to be a bug in Perl or
+a misunderstanding on my part; this invocation style does not always
+appear to be necessary.]
+
+Here is another way to build the same scanner. This one uses an
+explicit code reference, and also (unnecessarily, in this case) reads
+the whole file itself:
+
+  sub myscan {
+      my(@includes);
+      do {
+	  push(@includes, /\b\S*?\.smf\b/g);
+      } while <SCAN>;
+      @includes
+  }
+
+Note that the order of the loop is reversed, with the loop test at the
+end. This is because the first line is already read for you. This scanner
+can be attached to a source file by:
+
+  QuickScan $env \&myscan, "$_.smf";
+
+This final example, which scans a different type of input file, takes
+over the file scanning rather than being called for each input line:
+
+  $env->QuickScan(
+      sub { my(@includes) = ();
+	  do {
+	     push(@includes, $3)
+		 if /^(#include|import)\s+(\")(.+)(\")/ && $3
+	  } while <SCAN>;
+	  @includes
+      },
+      "$idlFileName",
+      "$env->{CPPPATH};$BUILD/ActiveContext/ACSCLientInterfaces"
+  );
+
+-->
+
+  <para>
+
+    &SCons; has built-in scanners that know how to look in
+    C, Fortran and IDL source files for information about
+    other files that targets built from those files depend on--for example,
+    in the case of files that use the C preprocessor,
+    the <filename>.h</filename> files that are specified
+    using <literal>#include</literal> lines in the source.
+    You can use the same mechanisms that &SCons; uses to create
+    its built-in scanners to write scanners of your own for file types
+    that &SCons; does not know how to scan "out of the box."
+
+  </para>
+
+  <section>
+  <title>A Simple Scanner Example</title>
+
+    <para>
+
+      Suppose, for example, that we want to create a simple scanner
+      for <filename>.foo</filename> files.
+      A <filename>.foo</filename> file contains some text that
+      will be processed,
+      and can include other files on lines that begin
+      with <literal>include</literal>
+      followed by a file name:
+
+    </para>
+
+    <programlisting>
+      include filename.foo
+    </programlisting>
+
+    <para>
+
+      Scanning a file will be handled by a Python function
+      that you must supply.
+      Here is a function that will use the Python
+      <filename>re</filename> module
+      to scan for the <literal>include</literal> lines in our example:
+
+    </para>
+
+    <programlisting>
+      import re
+      
+      include_re = re.compile(r'^include\s+(\S+)$', re.M)
+      
+      def kfile_scan(node, env, path, arg):
+          contents = node.get_text_contents()
+          return include_re.findall(contents)
+    </programlisting>
+
+    <para>
+
+      The scanner function must
+      accept the four specified arguments
+      and return a list of implicit dependencies.
+      Presumably, these would be dependencies found
+      from examining the contents of the file,
+      although the function can perform any
+      manipulation at all to generate the list of
+      dependencies.
+
+    </para>
+
+    <variablelist>
+
+      <varlistentry>
+      <term>node</term>
+
+      <listitem>
+      <para>
+
+      An &SCons; node object representing the file being scanned.
+      The path name to the file can be
+      used by converting the node to a string
+      using the <literal>str()</literal> function,
+      or an internal &SCons; <literal>get_text_contents()</literal>
+      object method can be used to fetch the contents.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>env</term>
+
+      <listitem>
+      <para>
+
+      The construction environment in effect for this scan.
+      The scanner function may choose to use construction
+      variables from this environment to affect its behavior.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>path</term>
+
+      <listitem>
+      <para>
+
+      A list of directories that form the search path for included files
+      for this scanner.
+      This is how &SCons; handles the &cv-link-CPPPATH; and &cv-link-LIBPATH;
+      variables.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+      <varlistentry>
+      <term>arg</term>
+
+      <listitem>
+      <para>
+
+      An optional argument that you can choose to
+      have passed to this scanner function by
+      various scanner instances.
+
+      </para>
+      </listitem>
+      </varlistentry>
+
+    </variablelist>
+
+    <para>
+
+    A Scanner object is created using the &Scanner; function,
+    which typically takes an <literal>skeys</literal> argument
+    to associate the type of file suffix with this scanner.
+    The Scanner object must then be associated with the
+    &cv-link-SCANNERS; construction variable of a construction environment,
+    typically by using the &Append; method:
+
+    </para>
+
+    <programlisting>
+       kscan = Scanner(function = kfile_scan,
+                       skeys = ['.k'])
+       env.Append(SCANNERS = kscan)
+    </programlisting>
+
+    <para>
+
+    When we put it all together, it looks like:
+
+    </para>
+
+    <programlisting>
+        import re
+
+        include_re = re.compile(r'^include\s+(\S+)$', re.M)
+
+        def kfile_scan(node, env, path):
+            contents = node.get_text_contents()
+            includes = include_re.findall(contents)
+            return includes
+
+        kscan = Scanner(function = kfile_scan,
+                        skeys = ['.k'])
+
+        env = Environment(ENV = {'PATH' : '/usr/local/bin'})
+        env.Append(SCANNERS = kscan)
+
+        env.Command('foo', 'foo.k', 'kprocess &lt; $SOURCES &gt; $TARGET')
+    </programlisting>
+
+    <!--
+
+    <para>
+
+      Now if we run &scons;
+      and then re-run it after changing the contents of
+      <filename>other_file</filename>,
+      the <filename>foo</filename>
+      target file will be automatically rebuilt:
+
+    </para>
+
+    <scons_output example="scan">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command output="    [CHANGE THE CONTENTS OF other_file]">edit other_file</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    -->
+
+  </section>
diff --git a/doc/user/sconf.in b/doc/user/sconf.in
new file mode 100644
index 0000000..c4092c9
--- /dev/null
+++ b/doc/user/sconf.in
@@ -0,0 +1,486 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  &SCons; has integrated support for multi-platform build configuration
+  similar to that offered by GNU &Autoconf;,
+  such as
+  figuring out what libraries or header files
+  are available on the local system.
+  This section describes how to use
+  this &SCons feature.
+
+  </para>
+
+  <note>
+  <para>
+  This chapter is still under development,
+  so not everything is explained as well as it should be.
+  See the &SCons; man page for additional information.
+  </para>
+  </note>
+
+  <section>
+  <title>&Configure_Contexts;</title>
+
+    <para>
+
+    The basic framework for multi-platform build configuration
+    in &SCons; is to attach a &configure_context; to a
+    construction environment by calling the &Configure; function,
+    perform a number of checks for
+    libraries, functions, header files, etc.,
+    and to then call the configure context's &Finish; method
+    to finish off the configuration:
+
+    </para>
+
+    <sconstruct>
+    env = Environment()
+    conf = Configure(env)
+    # Checks for libraries, header files, etc. go here!
+    env = conf.Finish()
+    </sconstruct>
+
+    <para>
+
+    &SCons; provides a number of basic checks,
+    as well as a mechanism for adding your own custom checks.
+
+    </para>
+
+    <para>
+
+    Note that &SCons; uses its own dependency
+    mechanism to determine when a check
+    needs to be run--that is,
+    &SCons; does not run the checks
+    every time it is invoked,
+    but caches the values returned by previous checks
+    and uses the cached values unless something has changed.
+    This saves a tremendous amount
+    of developer time while working on
+    cross-platform build issues.
+
+    </para>
+
+    <para>
+
+    The next sections describe
+    the basic checks that &SCons; supports,
+    as well as how to add your own custom checks.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Checking for the Existence of Header Files</title>
+
+    <para>
+
+    Testing the existence of a header file
+    requires knowing what language the header file is.
+    A configure context has a &CheckCHeader; method
+    that checks for the existence of a C header file:
+
+    </para>
+
+    <sconstruct>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckCHeader('math.h'):
+        print 'Math.h must be installed!'
+        Exit(1)
+    if conf.CheckCHeader('foo.h'):
+        conf.env.Append('-DHAS_FOO_H')
+    env = conf.Finish()
+    </sconstruct>
+
+    <para>
+
+    Note that you can choose to terminate
+    the build if a given header file doesn't exist,
+    or you can modify the construction environment
+    based on the existence of a header file.
+
+    </para>
+
+    <para>
+
+    If you need to check for the existence
+    a C++ header file,
+    use the &CheckCXXHeader; method:
+
+    </para>
+
+    <sconstruct>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckCXXHeader('vector.h'):
+        print 'vector.h must be installed!'
+        Exit(1)
+    env = conf.Finish()
+    </sconstruct>
+
+  </section>
+
+  <section>
+  <title>Checking for the Availability of a Function</title>
+
+    <para>
+
+    Check for the availability of a specific function
+    using the &CheckFunc; method:
+
+    </para>
+
+    <sconstruct>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckFunc('strcpy'):
+        print 'Did not find strcpy(), using local version'
+        conf.env.Append(CPPDEFINES = '-Dstrcpy=my_local_strcpy')
+    env = conf.Finish()
+    </sconstruct>
+
+  </section>
+
+  <section>
+  <title>Checking for the Availability of a Library</title>
+
+    <para>
+
+    Check for the availability of a library
+    using the &CheckLib; method.
+    You only specify the basename of the library,
+    you don't need to add a <literal>lib</literal>
+    prefix or a <literal>.a</literal> or <literal>.lib</literal> suffix:
+
+    </para>
+
+    <sconstruct>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckLib('m'):
+        print 'Did not find libm.a or m.lib, exiting!'
+        Exit(1)
+    env = conf.Finish()
+    </sconstruct>
+
+    <para>
+
+    Because the ability to use a library successfully
+    often depends on having access to a header file
+    that describes the library's interface,
+    you can check for a library
+    <emphasis>and</emphasis> a header file
+    at the same time by using the
+    &CheckLibWithHeader; method:
+
+    </para>
+
+    <sconstruct>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckLibWithHeader('m', 'math.h', 'c'):
+        print 'Did not find libm.a or m.lib, exiting!'
+        Exit(1)
+    env = conf.Finish()
+    </sconstruct>
+
+    <para>
+
+    This is essentially shorthand for
+    separate calls to the &CheckHeader; and &CheckLib;
+    functions.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Checking for the Availability of a &typedef;</title>
+
+    <para>
+
+    Check for the availability of a &typedef;
+    by using the &CheckType; method:
+
+    </para>
+
+    <sconstruct>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckType('off_t'):
+        print 'Did not find off_t typedef, assuming int'
+        conf.env.Append(CCFLAGS = '-Doff_t=int')
+    env = conf.Finish()
+    </sconstruct>
+
+    <para>
+
+    You can also add a string that will be
+    placed at the beginning of the test file
+    that will be used to check for the &typedef;.
+    This provide a way to specify
+    files that must be included to find the &typedef;:
+
+    </para>
+
+    <sconstruct>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckType('off_t', '#include &amp;lt;sys/types.h&amp;gt;\n'):
+        print 'Did not find off_t typedef, assuming int'
+        conf.env.Append(CCFLAGS = '-Doff_t=int')
+    env = conf.Finish()
+    </sconstruct>
+
+  </section>
+
+  <section>
+  <title>Adding Your Own Custom Checks</title>
+
+    <para>
+
+    A custom check is a Python function
+    that checks for a certain condition to exist
+    on the running system,
+    usually using methods that &SCons;
+    supplies to take care of the details
+    of checking whether a compilation succeeds,
+    a link succeeds,
+    a program is runnable,
+    etc.
+    A simple custom check for the existence of
+    a specific library might look as follows:
+
+    </para>
+
+    <sconstruct>
+    mylib_test_source_file = """
+    #include &amp;lt;mylib.h&amp;gt;
+    int main(int argc, char **argv)
+    {
+        MyLibrary mylib(argc, argv);
+        return 0;
+    }
+    """
+
+    def CheckMyLibrary(context):
+        context.Message('Checking for MyLibrary...')
+        result = context.TryLink(mylib_test_source_file, '.c')
+        context.Result(result)
+        return result
+    </sconstruct>
+
+    <para>
+
+    The &Message; and &Result; methods
+    should typically begin and end a custom check to
+    let the user know what's going on:
+    the &Message; call prints the
+    specified message (with no trailing newline)
+    and the &Result; call prints
+    <literal>yes</literal> if the check succeeds and
+    <literal>no</literal> if it doesn't.
+    The &TryLink; method
+    actually tests for whether the
+    specified program text
+    will successfully link.
+
+    </para>
+
+    <para>
+
+    (Note that a custom check can modify
+    its check based on any arguments you
+    choose to pass it,
+    or by using or modifying the configure context environment
+    in the <literal>context.env</literal> attribute.)
+
+    </para>
+
+    <para>
+
+    This custom check function is
+    then attached to the &configure_context;
+    by passing a dictionary
+    to the &Configure; call
+    that maps a name of the check
+    to the underlying function:
+
+    </para>
+
+    <sconstruct>
+    env = Environment()
+    conf = Configure(env, custom_tests = {'CheckMyLibrary' : CheckMyLibrary})
+    </sconstruct>
+
+    <para>
+
+    You'll typically want to make
+    the check and the function name the same,
+    as we've done here,
+    to avoid potential confusion.
+
+    </para>
+
+    <para>
+
+    We can then put these pieces together
+    and actually call the <literal>CheckMyLibrary</literal> check
+    as follows:
+
+    </para>
+
+    <sconstruct>
+    mylib_test_source_file = """
+    #include &amp;lt;mylib.h&amp;gt;
+    int main(int argc, char **argv)
+    {
+        MyLibrary mylib(argc, argv);
+        return 0;
+    }
+    """
+
+    def CheckMyLibrary(context):
+        context.Message('Checking for MyLibrary... ')
+        result = context.TryLink(mylib_test_source_file, '.c')
+        context.Result(result)
+        return result
+
+    env = Environment()
+    conf = Configure(env, custom_tests = {'CheckMyLibrary' : CheckMyLibrary})
+    if not conf.CheckMyLibrary():
+        print 'MyLibrary is not installed!'
+        Exit(1)
+    env = conf.Finish()
+
+    # We would then add actual calls like Program() to build
+    # something using the "env" construction environment.
+    </sconstruct>
+
+    <para>
+
+    If MyLibrary is not installed on the system,
+    the output will look like:
+
+    </para>
+
+    <screen>
+    % <userinput>scons</userinput>
+    scons: Reading SConscript file ...
+    Checking for MyLibrary... failed
+    MyLibrary is not installed!
+    </screen>
+
+    <para>
+
+    If MyLibrary is installed,
+    the output will look like:
+
+    </para>
+
+    <screen>
+    % <userinput>scons</userinput>
+    scons: Reading SConscript file ...
+    Checking for MyLibrary... failed
+    scons: done reading SConscript
+    scons: Building targets ...
+        .
+        .
+        .
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Not Configuring When Cleaning Targets</title>
+
+    <para>
+
+    Using multi-platform configuration
+    as described in the previous sections
+    will run the configuration commands
+    even when invoking
+    <userinput>scons -c</userinput>
+    to clean targets:
+
+    </para>
+
+    <screen>
+    % <userinput>scons -Q -c</userinput>
+    Checking for MyLibrary... yes
+    Removed foo.o
+    Removed foo
+    </screen>
+
+    <para>
+
+    Although running the platform checks
+    when removing targets doesn't hurt anything,
+    it's usually unnecessary.
+    You can avoid this by using the
+    &GetOption(); method to
+    check whether the <option>-c</option> (clean)
+    option has been invoked on the command line:
+
+    </para>
+
+    <sconstruct>
+    env = Environment()
+    if not env.GetOption('clean'):
+        conf = Configure(env, custom_tests = {'CheckMyLibrary' : CheckMyLibrary})
+        if not conf.CheckMyLibrary():
+            print 'MyLibrary is not installed!'
+            Exit(1)
+        env = conf.Finish()
+    </sconstruct>
+
+    <screen>
+    % <userinput>scons -Q -c</userinput>
+    Removed foo.o
+    Removed foo
+    </screen>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Controlling Configuration:  the &config; Option</title>
+
+    <para>
+
+    XXX -D, -u and -U
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/sconf.xml b/doc/user/sconf.xml
new file mode 100644
index 0000000..16ba534
--- /dev/null
+++ b/doc/user/sconf.xml
@@ -0,0 +1,486 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  &SCons; has integrated support for multi-platform build configuration
+  similar to that offered by GNU &Autoconf;,
+  such as
+  figuring out what libraries or header files
+  are available on the local system.
+  This section describes how to use
+  this &SCons; feature.
+
+  </para>
+
+  <note>
+  <para>
+  This chapter is still under development,
+  so not everything is explained as well as it should be.
+  See the &SCons; man page for additional information.
+  </para>
+  </note>
+
+  <section>
+  <title>&Configure_Contexts;</title>
+
+    <para>
+
+    The basic framework for multi-platform build configuration
+    in &SCons; is to attach a &configure_context; to a
+    construction environment by calling the &Configure; function,
+    perform a number of checks for
+    libraries, functions, header files, etc.,
+    and to then call the configure context's &Finish; method
+    to finish off the configuration:
+
+    </para>
+
+    <programlisting>
+    env = Environment()
+    conf = Configure(env)
+    # Checks for libraries, header files, etc. go here!
+    env = conf.Finish()
+    </programlisting>
+
+    <para>
+
+    &SCons; provides a number of basic checks,
+    as well as a mechanism for adding your own custom checks.
+
+    </para>
+
+    <para>
+
+    Note that &SCons; uses its own dependency
+    mechanism to determine when a check
+    needs to be run--that is,
+    &SCons; does not run the checks
+    every time it is invoked,
+    but caches the values returned by previous checks
+    and uses the cached values unless something has changed.
+    This saves a tremendous amount
+    of developer time while working on
+    cross-platform build issues.
+
+    </para>
+
+    <para>
+
+    The next sections describe
+    the basic checks that &SCons; supports,
+    as well as how to add your own custom checks.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Checking for the Existence of Header Files</title>
+
+    <para>
+
+    Testing the existence of a header file
+    requires knowing what language the header file is.
+    A configure context has a &CheckCHeader; method
+    that checks for the existence of a C header file:
+
+    </para>
+
+    <programlisting>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckCHeader('math.h'):
+        print 'Math.h must be installed!'
+        Exit(1)
+    if conf.CheckCHeader('foo.h'):
+        conf.env.Append('-DHAS_FOO_H')
+    env = conf.Finish()
+    </programlisting>
+
+    <para>
+
+    Note that you can choose to terminate
+    the build if a given header file doesn't exist,
+    or you can modify the construction environment
+    based on the existence of a header file.
+
+    </para>
+
+    <para>
+
+    If you need to check for the existence
+    a C++ header file,
+    use the &CheckCXXHeader; method:
+
+    </para>
+
+    <programlisting>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckCXXHeader('vector.h'):
+        print 'vector.h must be installed!'
+        Exit(1)
+    env = conf.Finish()
+    </programlisting>
+
+  </section>
+
+  <section>
+  <title>Checking for the Availability of a Function</title>
+
+    <para>
+
+    Check for the availability of a specific function
+    using the &CheckFunc; method:
+
+    </para>
+
+    <programlisting>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckFunc('strcpy'):
+        print 'Did not find strcpy(), using local version'
+        conf.env.Append(CPPDEFINES = '-Dstrcpy=my_local_strcpy')
+    env = conf.Finish()
+    </programlisting>
+
+  </section>
+
+  <section>
+  <title>Checking for the Availability of a Library</title>
+
+    <para>
+
+    Check for the availability of a library
+    using the &CheckLib; method.
+    You only specify the basename of the library,
+    you don't need to add a <literal>lib</literal>
+    prefix or a <literal>.a</literal> or <literal>.lib</literal> suffix:
+
+    </para>
+
+    <programlisting>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckLib('m'):
+        print 'Did not find libm.a or m.lib, exiting!'
+        Exit(1)
+    env = conf.Finish()
+    </programlisting>
+
+    <para>
+
+    Because the ability to use a library successfully
+    often depends on having access to a header file
+    that describes the library's interface,
+    you can check for a library
+    <emphasis>and</emphasis> a header file
+    at the same time by using the
+    &CheckLibWithHeader; method:
+
+    </para>
+
+    <programlisting>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckLibWithHeader('m', 'math.h', 'c'):
+        print 'Did not find libm.a or m.lib, exiting!'
+        Exit(1)
+    env = conf.Finish()
+    </programlisting>
+
+    <para>
+
+    This is essentially shorthand for
+    separate calls to the &CheckHeader; and &CheckLib;
+    functions.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Checking for the Availability of a &typedef;</title>
+
+    <para>
+
+    Check for the availability of a &typedef;
+    by using the &CheckType; method:
+
+    </para>
+
+    <programlisting>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckType('off_t'):
+        print 'Did not find off_t typedef, assuming int'
+        conf.env.Append(CCFLAGS = '-Doff_t=int')
+    env = conf.Finish()
+    </programlisting>
+
+    <para>
+
+    You can also add a string that will be
+    placed at the beginning of the test file
+    that will be used to check for the &typedef;.
+    This provide a way to specify
+    files that must be included to find the &typedef;:
+
+    </para>
+
+    <programlisting>
+    env = Environment()
+    conf = Configure(env)
+    if not conf.CheckType('off_t', '#include &lt;sys/types.h&gt;\n'):
+        print 'Did not find off_t typedef, assuming int'
+        conf.env.Append(CCFLAGS = '-Doff_t=int')
+    env = conf.Finish()
+    </programlisting>
+
+  </section>
+
+  <section>
+  <title>Adding Your Own Custom Checks</title>
+
+    <para>
+
+    A custom check is a Python function
+    that checks for a certain condition to exist
+    on the running system,
+    usually using methods that &SCons;
+    supplies to take care of the details
+    of checking whether a compilation succeeds,
+    a link succeeds,
+    a program is runnable,
+    etc.
+    A simple custom check for the existence of
+    a specific library might look as follows:
+
+    </para>
+
+    <programlisting>
+    mylib_test_source_file = """
+    #include &lt;mylib.h&gt;
+    int main(int argc, char **argv)
+    {
+        MyLibrary mylib(argc, argv);
+        return 0;
+    }
+    """
+
+    def CheckMyLibrary(context):
+        context.Message('Checking for MyLibrary...')
+        result = context.TryLink(mylib_test_source_file, '.c')
+        context.Result(result)
+        return result
+    </programlisting>
+
+    <para>
+
+    The &Message; and &Result; methods
+    should typically begin and end a custom check to
+    let the user know what's going on:
+    the &Message; call prints the
+    specified message (with no trailing newline)
+    and the &Result; call prints
+    <literal>yes</literal> if the check succeeds and
+    <literal>no</literal> if it doesn't.
+    The &TryLink; method
+    actually tests for whether the
+    specified program text
+    will successfully link.
+
+    </para>
+
+    <para>
+
+    (Note that a custom check can modify
+    its check based on any arguments you
+    choose to pass it,
+    or by using or modifying the configure context environment
+    in the <literal>context.env</literal> attribute.)
+
+    </para>
+
+    <para>
+
+    This custom check function is
+    then attached to the &configure_context;
+    by passing a dictionary
+    to the &Configure; call
+    that maps a name of the check
+    to the underlying function:
+
+    </para>
+
+    <programlisting>
+    env = Environment()
+    conf = Configure(env, custom_tests = {'CheckMyLibrary' : CheckMyLibrary})
+    </programlisting>
+
+    <para>
+
+    You'll typically want to make
+    the check and the function name the same,
+    as we've done here,
+    to avoid potential confusion.
+
+    </para>
+
+    <para>
+
+    We can then put these pieces together
+    and actually call the <literal>CheckMyLibrary</literal> check
+    as follows:
+
+    </para>
+
+    <programlisting>
+    mylib_test_source_file = """
+    #include &lt;mylib.h&gt;
+    int main(int argc, char **argv)
+    {
+        MyLibrary mylib(argc, argv);
+        return 0;
+    }
+    """
+
+    def CheckMyLibrary(context):
+        context.Message('Checking for MyLibrary... ')
+        result = context.TryLink(mylib_test_source_file, '.c')
+        context.Result(result)
+        return result
+
+    env = Environment()
+    conf = Configure(env, custom_tests = {'CheckMyLibrary' : CheckMyLibrary})
+    if not conf.CheckMyLibrary():
+        print 'MyLibrary is not installed!'
+        Exit(1)
+    env = conf.Finish()
+
+    # We would then add actual calls like Program() to build
+    # something using the "env" construction environment.
+    </programlisting>
+
+    <para>
+
+    If MyLibrary is not installed on the system,
+    the output will look like:
+
+    </para>
+
+    <screen>
+    % <userinput>scons</userinput>
+    scons: Reading SConscript file ...
+    Checking for MyLibrary... failed
+    MyLibrary is not installed!
+    </screen>
+
+    <para>
+
+    If MyLibrary is installed,
+    the output will look like:
+
+    </para>
+
+    <screen>
+    % <userinput>scons</userinput>
+    scons: Reading SConscript file ...
+    Checking for MyLibrary... failed
+    scons: done reading SConscript
+    scons: Building targets ...
+        .
+        .
+        .
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Not Configuring When Cleaning Targets</title>
+
+    <para>
+
+    Using multi-platform configuration
+    as described in the previous sections
+    will run the configuration commands
+    even when invoking
+    <userinput>scons -c</userinput>
+    to clean targets:
+
+    </para>
+
+    <screen>
+    % <userinput>scons -Q -c</userinput>
+    Checking for MyLibrary... yes
+    Removed foo.o
+    Removed foo
+    </screen>
+
+    <para>
+
+    Although running the platform checks
+    when removing targets doesn't hurt anything,
+    it's usually unnecessary.
+    You can avoid this by using the
+    &GetOption;(); method to
+    check whether the <option>-c</option> (clean)
+    option has been invoked on the command line:
+
+    </para>
+
+    <programlisting>
+    env = Environment()
+    if not env.GetOption('clean'):
+        conf = Configure(env, custom_tests = {'CheckMyLibrary' : CheckMyLibrary})
+        if not conf.CheckMyLibrary():
+            print 'MyLibrary is not installed!'
+            Exit(1)
+        env = conf.Finish()
+    </programlisting>
+
+    <screen>
+    % <userinput>scons -Q -c</userinput>
+    Removed foo.o
+    Removed foo
+    </screen>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Controlling Configuration:  the &config; Option</title>
+
+    <para>
+
+    XXX -D, -u and -U
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/separate.in b/doc/user/separate.in
new file mode 100644
index 0000000..edc6da8
--- /dev/null
+++ b/doc/user/separate.in
@@ -0,0 +1,540 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 Separating source and build trees
+
+It's often desirable to keep any derived files from the build completely
+separate from the source files. This makes it much easier to keep track of
+just what is a source file, and also makes it simpler to handle B<variant>
+builds, especially if you want the variant builds to co-exist.
+
+=head2 Separating build and source directories using the Link command
+
+Cons provides a simple mechanism that handles all of these requirements. The
+C<Link> command is invoked as in this example:
+
+  Link 'build' => 'src';
+
+The specified directories are ``linked'' to the specified source
+directory. Let's suppose that you setup a source directory, F<src>, with the
+sub-directories F<world> and F<hello> below it, as in the previous
+example. You could then substitute for the original build lines the
+following:
+
+  Build qw(
+	build/world/Conscript
+	build/hello/Conscript
+  );
+
+Notice that you treat the F<Conscript> file as if it existed in the build
+directory. Now if you type the same command as before, you will get the
+following results:
+
+  % cons export
+  Install build/world/world.h as export/include/world.h
+  cc -Iexport/include -c build/hello/hello.c -o build/hello/hello.o
+  cc -Iexport/include -c build/world/world.c -o build/world/world.o
+  ar r build/world/libworld.a build/world/world.o
+  ar: creating build/world/libworld.a
+  ranlib build/world/libworld.a
+  Install build/world/libworld.a as export/lib/libworld.a
+  cc -o build/hello/hello build/hello/hello.o -Lexport/lib -lworld
+  Install build/hello/hello as export/bin/hello
+
+Again, Cons has taken care of the details for you. In particular, you will
+notice that all the builds are done using source files and object files from
+the build directory. For example, F<build/world/world.o> is compiled from
+F<build/world/world.c>, and F<export/include/world.h> is installed from
+F<build/world/world.h>. This is accomplished on most systems by the simple
+expedient of ``hard'' linking the required files from each source directory
+into the appropriate build directory.
+
+The links are maintained correctly by Cons, no matter what you do to the
+source directory. If you modify a source file, your editor may do this ``in
+place'' or it may rename it first and create a new file. In the latter case,
+any hard link will be lost. Cons will detect this condition the next time
+the source file is needed, and will relink it appropriately.
+
+You'll also notice, by the way, that B<no> changes were required to the
+underlying F<Conscript> files. And we can go further, as we shall see in the
+next section.
+
+=head2 Explicit references to the source directory
+
+When using the C<Link> command on some operating systems or with some
+tool chains, it's sometimes useful to have a command actually use
+the path name to the source directory, not the build directory.  For
+example, on systems that must copy, not "hard link," the F<src/> and
+F<build/> copies of C<Linked> files, using the F<src/> path of a file
+name might make an editor aware that a syntax error must be fixed in the
+source directory, not the build directory.
+
+You can tell Cons that you want to use the "source path" for a file by
+preceding the file name with a ``!'' (exclamation point).  For example,
+if we add a ``!'' to the beginning of a source file:
+
+  Program $env "foo", "!foo.c";	# Notice initial ! on foo.c
+
+Cons will compile the target as follows:
+
+  cc -c src/foo.c -o build/foo.o
+  cc -o build/foo build/foo.o
+
+Notice that Cons has compiled the program from the the F<src/foo.c>
+source file.  Without the initial ``!'', Cons would have compiled the
+program using the F<build/foo.c> path name.
+
+-->
+
+  <para>
+
+  It's often useful to keep any built files completely
+  separate from the source files.
+  In &SCons;, this is usually done by creating one or more separate
+  <emphasis>variant directory trees</emphasis>
+  that are used to hold the built objects files, libraries,
+  and executable programs, etc.
+  for a specific flavor, or variant, of build.
+  &SCons; provides two ways to do this,
+  one through the &SConscript; function that we've already seen,
+  and the second through a more flexible &VariantDir; function.
+
+  </para>
+
+  <para>
+
+  One historical note:  the &VariantDir; function
+  used to be called &BuildDir;.
+  That name is still supported
+  but has been deprecated
+  because the &SCons; functionality
+  differs from the model of a "build directory"
+  implemented by other build systems like the GNU Autotools.
+
+  </para>
+
+  <section>
+  <title>Specifying a Variant Directory Tree as Part of an &SConscript; Call</title>
+
+    <para>
+
+    The most straightforward way to establish a variant directory tree
+    uses the fact that the usual way to
+    set up a build hierarchy is to have an
+    &SConscript; file in the source subdirectory.
+    If you then pass a &variant_dir; argument to the
+    &SConscript; function call:
+
+    </para>
+
+    <scons_example name="ex1">
+      <file name="SConstruct" printme="1">
+      SConscript('src/SConscript', variant_dir='build')
+      </file>
+      <file name="src/SConscript">
+      env = Environment()
+      env.Program('hello.c')
+      </file>
+      <file name="src/hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    &SCons; will then build all of the files in
+    the &build; subdirectory:
+
+    </para>
+
+    <scons_output example="ex1">
+      <scons_output_command>ls src</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>ls build</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    But wait a minute--what's going on here?
+    &SCons; created the object file
+    <filename>build/hello.o</filename>
+    in the &build; subdirectory,
+    as expected.
+    But even though our &hello_c; file lives in the &src; subdirectory,
+    &SCons; has actually compiled a
+    <filename>build/hello.c</filename> file
+    to create the object file.
+
+    </para>
+
+    <para>
+
+    What's happened is that &SCons; has <emphasis>duplicated</emphasis>
+    the &hello_c; file from the &src; subdirectory
+    to the &build; subdirectory,
+    and built the program from there.
+    The next section explains why &SCons; does this.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Why &SCons; Duplicates Source Files in a Variant Directory Tree</title>
+
+    <para>
+
+    &SCons; duplicates source files in variant directory trees
+    because it's the most straightforward way to guarantee a correct build
+    <emphasis>regardless of include-file directory paths,
+    relative references between files,
+    or tool support for putting files in different locations</emphasis>,
+    and the &SCons; philosophy is to, by default,
+    guarantee a correct build in all cases.
+
+    </para>
+
+    <para>
+
+    The most direct reason to duplicate source files
+    in variant directories
+    is simply that some tools (mostly older versions)
+    are written to only build their output files
+    in the same directory as the source files.
+    In this case, the choices are either
+    to build the output file in the source directory
+    and move it to the variant directory,
+    or to duplicate the source files in the variant directory.
+
+    </para>
+
+    <para>
+
+    Additionally,
+    relative references between files
+    can cause problems if we don't
+    just duplicate the hierarchy of source files
+    in the variant directory.
+    You can see this at work in
+    use of the C preprocessor <literal>#include</literal>
+    mechanism with double quotes, not angle brackets:
+
+    </para>
+
+    <sconstruct>
+      #include "file.h"
+    </sconstruct>
+
+    <para>
+
+    The <emphasis>de facto</emphasis> standard behavior
+    for most C compilers in this case
+    is to first look in the same directory
+    as the source file that contains the <literal>#include</literal> line,
+    then to look in the directories in the preprocessor search path.
+    Add to this that the &SCons; implementation of
+    support for code repositories
+    (described below)
+    means not all of the files
+    will be found in the same directory hierarchy,
+    and the simplest way to make sure
+    that the right include file is found
+    is to duplicate the source files into the variant directory,
+    which provides a correct build
+    regardless of the original location(s) of the source files.
+
+    </para>
+
+    <para>
+
+    Although source-file duplication guarantees a correct build
+    even in these end-cases,
+    it <emphasis>can</emphasis> usually be safely disabled.
+    The next section describes
+    how you can disable the duplication of source files
+    in the variant directory.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Telling &SCons; to Not Duplicate Source Files in the Variant Directory Tree</title>
+
+    <para>
+
+    In most cases and with most tool sets,
+    &SCons; can place its target files in a build subdirectory
+    <emphasis>without</emphasis>
+    duplicating the source files
+    and everything will work just fine.
+    You can disable the default &SCons; behavior
+    by specifying <literal>duplicate=0</literal>
+    when you call the &SConscript; function:
+
+    </para>
+
+    <sconstruct>
+      SConscript('src/SConscript', variant_dir='build', duplicate=0)
+    </sconstruct>
+
+    <para>
+
+    When this flag is specified,
+    &SCons; uses the variant directory
+    like most people expect--that is,
+    the output files are placed in the variant directory
+    while the source files stay in the source directory:
+
+    </para>
+
+    <screen>
+      % <userinput>ls src</userinput>
+      SConscript
+      hello.c
+      % <userinput>scons -Q</userinput>
+      cc -c src/hello.c -o build/hello.o
+      cc -o build/hello build/hello.o
+      % <userinput>ls build</userinput>
+      hello
+      hello.o
+    </screen>
+
+  </section>
+
+  <section>
+  <title>The &VariantDir; Function</title>
+
+    <para>
+
+    Use the &VariantDir; function to establish that target
+    files should be built in a separate directory
+    from the source files:
+
+    </para>
+
+    <scons_example name="ex_builddir">
+      <file name="SConstruct" printme="1">
+      VariantDir('build', 'src')
+      env = Environment()
+      env.Program('build/hello.c')
+      </file>
+      <file name="src/hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Note that when you're not using
+    an &SConscript; file in the &src; subdirectory,
+    you must actually specify that
+    the program must be built from
+    the <filename>build/hello.c</filename>
+    file that &SCons; will duplicate in the
+    &build; subdirectory.
+
+    </para>
+
+    <para>
+
+    When using the &VariantDir; function directly,
+    &SCons; still duplicates the source files
+    in the variant directory by default:
+
+    </para>
+
+    <scons_output example="ex_builddir">
+      <scons_output_command>ls src</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>ls build</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    You can specify the same <literal>duplicate=0</literal> argument
+    that you can specify for an &SConscript; call:
+
+    </para>
+
+    <scons_example name="ex_duplicate_0">
+      <file name="SConstruct" printme="1">
+      VariantDir('build', 'src', duplicate=0)
+      env = Environment()
+      env.Program('build/hello.c')
+      </file>
+      <file name="src/hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    In which case &SCons;
+    will disable duplication of the source files:
+
+    </para>
+
+    <scons_output example="ex_duplicate_0">
+      <scons_output_command>ls src</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>ls build</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+  <title>Using &VariantDir; With an &SConscript; File</title>
+
+    <para>
+
+    Even when using the &VariantDir; function,
+    it's much more natural to use it with
+    a subsidiary &SConscript; file.
+    For example, if the
+    <filename>src/SConscript</filename>
+    looks like this:
+
+    </para>
+
+    <scons_example name="example_builddir_sconscript">
+      <file name="SConstruct">
+      VariantDir('build', 'src')
+      SConscript('build/SConscript')
+      </file>
+      <file name="src/SConscript" printme="1">
+      env = Environment()
+      env.Program('hello.c')
+      </file>
+      <file name="src/hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+    </scons_example>
+
+    <para>
+
+    Then our &SConstruct; file could look like:
+
+    </para>
+
+    <scons_example_file example="example_builddir_sconscript" name="SConstruct">
+    </scons_example_file>
+
+    <para>
+
+    Yielding the following output:
+
+    </para>
+
+    <scons_output example="example_builddir_sconscript">
+      <scons_output_command>ls src</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>ls build</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Notice that this is completely equivalent
+    to the use of &SConscript; that we
+    learned about in the previous section.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Using &Glob; with &VariantDir;</title>
+
+    <para>
+
+    The &Glob; file name pattern matching function
+    works just as usual when using &VariantDir;.
+    For example, if the
+    <filename>src/SConscript</filename>
+    looks like this:
+
+    </para>
+
+    <scons_example name="example_glob_builddir_sconscript">
+      <file name="SConstruct">
+      VariantDir('build', 'src')
+      SConscript('build/SConscript')
+      </file>
+      <file name="src/SConscript" printme="1">
+      env = Environment()
+      env.Program('hello', Glob('*.c'))
+      </file>
+      <file name="src/f1.c">
+      #include "f2.h"
+      int main() { printf(f2()); }
+      </file>
+      <file name="src/f2.c">
+      const char * f2() { return("Hello, world!\n"); }
+      </file>
+      <file name="src/f2.h">
+      const char * f2();
+      </file>
+    </scons_example>
+
+    <para>
+
+    Then with the same &SConstruct; file as in the previous section,
+    and source files <filename>f1.c</filename>
+    and <filename>f2.c</filename> in src,
+    we would see the following output:
+
+    </para>
+
+    <scons_output example="example_glob_builddir_sconscript">
+      <scons_output_command>ls src</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>ls build</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The &Glob; function returns Nodes in the
+    <filename>build/</filename> tree, as you'd expect.
+
+    </para>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Why You'd Want to Call &VariantDir; Instead of &SConscript;</title>
+
+    <para>
+
+    XXX why call VariantDir() instead of SConscript(variant_dir=)
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/separate.xml b/doc/user/separate.xml
new file mode 100644
index 0000000..fd5bdf0
--- /dev/null
+++ b/doc/user/separate.xml
@@ -0,0 +1,520 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 Separating source and build trees
+
+It's often desirable to keep any derived files from the build completely
+separate from the source files. This makes it much easier to keep track of
+just what is a source file, and also makes it simpler to handle B<variant>
+builds, especially if you want the variant builds to co-exist.
+
+=head2 Separating build and source directories using the Link command
+
+Cons provides a simple mechanism that handles all of these requirements. The
+C<Link> command is invoked as in this example:
+
+  Link 'build' => 'src';
+
+The specified directories are ``linked'' to the specified source
+directory. Let's suppose that you setup a source directory, F<src>, with the
+sub-directories F<world> and F<hello> below it, as in the previous
+example. You could then substitute for the original build lines the
+following:
+
+  Build qw(
+	build/world/Conscript
+	build/hello/Conscript
+  );
+
+Notice that you treat the F<Conscript> file as if it existed in the build
+directory. Now if you type the same command as before, you will get the
+following results:
+
+  % cons export
+  Install build/world/world.h as export/include/world.h
+  cc -Iexport/include -c build/hello/hello.c -o build/hello/hello.o
+  cc -Iexport/include -c build/world/world.c -o build/world/world.o
+  ar r build/world/libworld.a build/world/world.o
+  ar: creating build/world/libworld.a
+  ranlib build/world/libworld.a
+  Install build/world/libworld.a as export/lib/libworld.a
+  cc -o build/hello/hello build/hello/hello.o -Lexport/lib -lworld
+  Install build/hello/hello as export/bin/hello
+
+Again, Cons has taken care of the details for you. In particular, you will
+notice that all the builds are done using source files and object files from
+the build directory. For example, F<build/world/world.o> is compiled from
+F<build/world/world.c>, and F<export/include/world.h> is installed from
+F<build/world/world.h>. This is accomplished on most systems by the simple
+expedient of ``hard'' linking the required files from each source directory
+into the appropriate build directory.
+
+The links are maintained correctly by Cons, no matter what you do to the
+source directory. If you modify a source file, your editor may do this ``in
+place'' or it may rename it first and create a new file. In the latter case,
+any hard link will be lost. Cons will detect this condition the next time
+the source file is needed, and will relink it appropriately.
+
+You'll also notice, by the way, that B<no> changes were required to the
+underlying F<Conscript> files. And we can go further, as we shall see in the
+next section.
+
+=head2 Explicit references to the source directory
+
+When using the C<Link> command on some operating systems or with some
+tool chains, it's sometimes useful to have a command actually use
+the path name to the source directory, not the build directory.  For
+example, on systems that must copy, not "hard link," the F<src/> and
+F<build/> copies of C<Linked> files, using the F<src/> path of a file
+name might make an editor aware that a syntax error must be fixed in the
+source directory, not the build directory.
+
+You can tell Cons that you want to use the "source path" for a file by
+preceding the file name with a ``!'' (exclamation point).  For example,
+if we add a ``!'' to the beginning of a source file:
+
+  Program $env "foo", "!foo.c";	# Notice initial ! on foo.c
+
+Cons will compile the target as follows:
+
+  cc -c src/foo.c -o build/foo.o
+  cc -o build/foo build/foo.o
+
+Notice that Cons has compiled the program from the the F<src/foo.c>
+source file.  Without the initial ``!'', Cons would have compiled the
+program using the F<build/foo.c> path name.
+
+-->
+
+  <para>
+
+  It's often useful to keep any built files completely
+  separate from the source files.
+  In &SCons;, this is usually done by creating one or more separate
+  <emphasis>variant directory trees</emphasis>
+  that are used to hold the built objects files, libraries,
+  and executable programs, etc.
+  for a specific flavor, or variant, of build.
+  &SCons; provides two ways to do this,
+  one through the &SConscript; function that we've already seen,
+  and the second through a more flexible &VariantDir; function.
+
+  </para>
+
+  <para>
+
+  One historical note:  the &VariantDir; function
+  used to be called &BuildDir;.
+  That name is still supported
+  but has been deprecated
+  because the &SCons; functionality
+  differs from the model of a "build directory"
+  implemented by other build systems like the GNU Autotools.
+
+  </para>
+
+  <section>
+  <title>Specifying a Variant Directory Tree as Part of an &SConscript; Call</title>
+
+    <para>
+
+    The most straightforward way to establish a variant directory tree
+    uses the fact that the usual way to
+    set up a build hierarchy is to have an
+    &SConscript; file in the source subdirectory.
+    If you then pass a &variant_dir; argument to the
+    &SConscript; function call:
+
+    </para>
+
+    <programlisting>
+      SConscript('src/SConscript', variant_dir='build')
+    </programlisting>
+
+    <para>
+
+    &SCons; will then build all of the files in
+    the &build; subdirectory:
+
+    </para>
+
+    <screen>
+      % <userinput>ls src</userinput>
+      SConscript  hello.c
+      % <userinput>scons -Q</userinput>
+      cc -o build/hello.o -c build/hello.c
+      cc -o build/hello build/hello.o
+      % <userinput>ls build</userinput>
+      SConscript  hello  hello.c  hello.o
+    </screen>
+
+    <para>
+
+    But wait a minute--what's going on here?
+    &SCons; created the object file
+    <filename>build/hello.o</filename>
+    in the &build; subdirectory,
+    as expected.
+    But even though our &hello_c; file lives in the &src; subdirectory,
+    &SCons; has actually compiled a
+    <filename>build/hello.c</filename> file
+    to create the object file.
+
+    </para>
+
+    <para>
+
+    What's happened is that &SCons; has <emphasis>duplicated</emphasis>
+    the &hello_c; file from the &src; subdirectory
+    to the &build; subdirectory,
+    and built the program from there.
+    The next section explains why &SCons; does this.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Why &SCons; Duplicates Source Files in a Variant Directory Tree</title>
+
+    <para>
+
+    &SCons; duplicates source files in variant directory trees
+    because it's the most straightforward way to guarantee a correct build
+    <emphasis>regardless of include-file directory paths,
+    relative references between files,
+    or tool support for putting files in different locations</emphasis>,
+    and the &SCons; philosophy is to, by default,
+    guarantee a correct build in all cases.
+
+    </para>
+
+    <para>
+
+    The most direct reason to duplicate source files
+    in variant directories
+    is simply that some tools (mostly older versions)
+    are written to only build their output files
+    in the same directory as the source files.
+    In this case, the choices are either
+    to build the output file in the source directory
+    and move it to the variant directory,
+    or to duplicate the source files in the variant directory.
+
+    </para>
+
+    <para>
+
+    Additionally,
+    relative references between files
+    can cause problems if we don't
+    just duplicate the hierarchy of source files
+    in the variant directory.
+    You can see this at work in
+    use of the C preprocessor <literal>#include</literal>
+    mechanism with double quotes, not angle brackets:
+
+    </para>
+
+    <programlisting>
+      #include "file.h"
+    </programlisting>
+
+    <para>
+
+    The <emphasis>de facto</emphasis> standard behavior
+    for most C compilers in this case
+    is to first look in the same directory
+    as the source file that contains the <literal>#include</literal> line,
+    then to look in the directories in the preprocessor search path.
+    Add to this that the &SCons; implementation of
+    support for code repositories
+    (described below)
+    means not all of the files
+    will be found in the same directory hierarchy,
+    and the simplest way to make sure
+    that the right include file is found
+    is to duplicate the source files into the variant directory,
+    which provides a correct build
+    regardless of the original location(s) of the source files.
+
+    </para>
+
+    <para>
+
+    Although source-file duplication guarantees a correct build
+    even in these end-cases,
+    it <emphasis>can</emphasis> usually be safely disabled.
+    The next section describes
+    how you can disable the duplication of source files
+    in the variant directory.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Telling &SCons; to Not Duplicate Source Files in the Variant Directory Tree</title>
+
+    <para>
+
+    In most cases and with most tool sets,
+    &SCons; can place its target files in a build subdirectory
+    <emphasis>without</emphasis>
+    duplicating the source files
+    and everything will work just fine.
+    You can disable the default &SCons; behavior
+    by specifying <literal>duplicate=0</literal>
+    when you call the &SConscript; function:
+
+    </para>
+
+    <programlisting>
+      SConscript('src/SConscript', variant_dir='build', duplicate=0)
+    </programlisting>
+
+    <para>
+
+    When this flag is specified,
+    &SCons; uses the variant directory
+    like most people expect--that is,
+    the output files are placed in the variant directory
+    while the source files stay in the source directory:
+
+    </para>
+
+    <screen>
+      % <userinput>ls src</userinput>
+      SConscript
+      hello.c
+      % <userinput>scons -Q</userinput>
+      cc -c src/hello.c -o build/hello.o
+      cc -o build/hello build/hello.o
+      % <userinput>ls build</userinput>
+      hello
+      hello.o
+    </screen>
+
+  </section>
+
+  <section>
+  <title>The &VariantDir; Function</title>
+
+    <para>
+
+    Use the &VariantDir; function to establish that target
+    files should be built in a separate directory
+    from the source files:
+
+    </para>
+
+    <programlisting>
+      VariantDir('build', 'src')
+      env = Environment()
+      env.Program('build/hello.c')
+    </programlisting>
+
+    <para>
+
+    Note that when you're not using
+    an &SConscript; file in the &src; subdirectory,
+    you must actually specify that
+    the program must be built from
+    the <filename>build/hello.c</filename>
+    file that &SCons; will duplicate in the
+    &build; subdirectory.
+
+    </para>
+
+    <para>
+
+    When using the &VariantDir; function directly,
+    &SCons; still duplicates the source files
+    in the variant directory by default:
+
+    </para>
+
+    <screen>
+      % <userinput>ls src</userinput>
+      hello.c
+      % <userinput>scons -Q</userinput>
+      cc -o build/hello.o -c build/hello.c
+      cc -o build/hello build/hello.o
+      % <userinput>ls build</userinput>
+      hello  hello.c  hello.o
+    </screen>
+
+    <para>
+
+    You can specify the same <literal>duplicate=0</literal> argument
+    that you can specify for an &SConscript; call:
+
+    </para>
+
+    <programlisting>
+      VariantDir('build', 'src', duplicate=0)
+      env = Environment()
+      env.Program('build/hello.c')
+    </programlisting>
+
+    <para>
+
+    In which case &SCons;
+    will disable duplication of the source files:
+
+    </para>
+
+    <screen>
+      % <userinput>ls src</userinput>
+      hello.c
+      % <userinput>scons -Q</userinput>
+      cc -o build/hello.o -c src/hello.c
+      cc -o build/hello build/hello.o
+      % <userinput>ls build</userinput>
+      hello  hello.o
+    </screen>
+
+  </section>
+
+  <section>
+  <title>Using &VariantDir; With an &SConscript; File</title>
+
+    <para>
+
+    Even when using the &VariantDir; function,
+    it's much more natural to use it with
+    a subsidiary &SConscript; file.
+    For example, if the
+    <filename>src/SConscript</filename>
+    looks like this:
+
+    </para>
+
+    <programlisting>
+      env = Environment()
+      env.Program('hello.c')
+    </programlisting>
+
+    <para>
+
+    Then our &SConstruct; file could look like:
+
+    </para>
+
+    
+    <programlisting>
+      VariantDir('build', 'src')
+      SConscript('build/SConscript')
+      </programlisting>
+
+    <para>
+
+    Yielding the following output:
+
+    </para>
+
+    <screen>
+      % <userinput>ls src</userinput>
+      SConscript  hello.c
+      % <userinput>scons -Q</userinput>
+      cc -o build/hello.o -c build/hello.c
+      cc -o build/hello build/hello.o
+      % <userinput>ls build</userinput>
+      SConscript  hello  hello.c  hello.o
+    </screen>
+
+    <para>
+
+    Notice that this is completely equivalent
+    to the use of &SConscript; that we
+    learned about in the previous section.
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>Using &Glob; with &VariantDir;</title>
+
+    <para>
+
+    The &Glob; file name pattern matching function
+    works just as usual when using &VariantDir;.
+    For example, if the
+    <filename>src/SConscript</filename>
+    looks like this:
+
+    </para>
+
+    <programlisting>
+      env = Environment()
+      env.Program('hello', Glob('*.c'))
+    </programlisting>
+
+    <para>
+
+    Then with the same &SConstruct; file as in the previous section,
+    and source files <filename>f1.c</filename>
+    and <filename>f2.c</filename> in src,
+    we would see the following output:
+
+    </para>
+
+    <screen>
+      % <userinput>ls src</userinput>
+      SConscript  f1.c  f2.c  f2.h
+      % <userinput>scons -Q</userinput>
+      cc -o build/f1.o -c build/f1.c
+      cc -o build/f2.o -c build/f2.c
+      cc -o build/hello build/f1.o build/f2.o
+      % <userinput>ls build</userinput>
+      SConscript  f1.c  f1.o  f2.c  f2.h  f2.o  hello
+    </screen>
+
+    <para>
+
+    The &Glob; function returns Nodes in the
+    <filename>build/</filename> tree, as you'd expect.
+
+    </para>
+
+  </section>
+
+  <!--
+
+  <section>
+  <title>Why You'd Want to Call &VariantDir; Instead of &SConscript;</title>
+
+    <para>
+
+    XXX why call VariantDir() instead of SConscript(variant_dir=)
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/sideeffect.in b/doc/user/sideeffect.in
new file mode 100644
index 0000000..58c7306
--- /dev/null
+++ b/doc/user/sideeffect.in
@@ -0,0 +1,216 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <!--
+
+ <para>
+
+ If &SCons; is unaware that a build step produces an extra file,
+ the &SideEffect; method can be used to identify it,
+ so that the file can be used as a dependency in subsequent build steps.
+ However, the primary use for the &SideEffect; method
+ is to prevent two build steps from simultaneously modifying the same file.
+
+ </para>
+
+ TODO: currently doesn't work due to issue #2154:
+ http://scons.tigris.org/issues/show_bug.cgi?id=2154
+
+ <para>
+
+ If more than one build step creates or manipulates the same file,
+ it can cause unpleasant results if both build steps are run at the same time.
+ The shared file is declared as a side-effect of building the primary targets
+ and &SCons; will prevent the two build steps from running in parallel.
+
+ </para>
+
+ <para>
+
+ In this example, the <filename>SConscript</filename> uses
+ &SideEffect; to inform &SCons; about the additional output file.
+
+ </para>
+
+ <scons_example name="SideEffectSimple">
+   <file name="SConstruct" printme="1">
+    env = Environment()
+    f2 = env.Command('file2', 'log', Copy('$TARGET', '$SOURCE'))
+    f1 = env.Command('file1', [],
+        'echo >$TARGET data1; echo >log updated file1'))
+    env.SideEffect('log', env.Command('file1', [],
+        'echo >$TARGET data1; echo >log updated file1'))
+   </file>
+ </scons_example>
+
+ <para>
+
+ Even when run in parallel mode, &SCons; will run the two steps in order:
+
+ </para>
+
+ <scons_output example="SideEffectSimple">
+    <scons_output_command>scons -Q --jobs=2</scons_output_command>
+ </scons_output>
+
+ -->
+
+ <para>
+
+ Sometimes a program the you need to call
+ to build a target file
+ will also update another file,
+ such as a log file describing what the program
+ does while building the target.
+ For example, we the folowing configuration
+ would have &SCons; invoke a hypothetical
+ script named <application>build</application>
+ (in the local directory)
+ with command-line arguments that write
+ log information to a common
+ <filename>logfile.txt</filename> file:
+
+ </para>
+
+ <screen>
+ env = Environment()
+ env.Command('file1.out', 'file.in',
+             './build --log logfile.txt $SOURCE $TARGET')
+ env.Command('file2.out', 'file.in',
+             './build --log logfile.txt $SOURCE $TARGET')
+ <screen>
+
+ <para>
+
+ This can cause problems when running
+ the build in parallel if
+ &SCons; decides to update both targets
+ by running both program invocations at the same time.
+ The multiple program invocations
+ may interfere with each other
+ writing to the common log file,
+ leading at best to intermixed output in the log file,
+ and at worst to an actual failed build
+ (on a system like Windows, for example,
+ where only one process at a time can open the log file for writing).
+
+ </para>
+
+ <para>
+
+ We can make sure that &SCons; does not
+ run these <application>build</application>
+ commands at the same time
+ by using the &SideEffect; function
+ to specify that updating
+ the <filename>logfile.txt</filename> file
+ is a side effect of building the specified
+ <filename>file1</filename>
+ and
+ <filename>file2</filename>
+ target files:
+
+ </para>
+
+ <scons_example name="SideEffectShared">
+   <file name="SConstruct" printme="1">
+   env = Environment()
+   f1 = env.Command('file1.out', 'file1.in',
+                    './build --log logfile.txt $SOURCE $TARGET')
+   f2 = env.Command('file2.out', 'file2.in',
+                    './build --log logfile.txt $SOURCE $TARGET')
+   env.SideEffect('logfile.txt', f1 + f2)
+   </file>
+   <file name="file1.in">file1.in</file>
+   <file name="file2.in">file2.in</file>
+   <file name="build" chmod="0755">
+   cat
+   </file>
+ </scons_example>
+
+ <para>
+
+ </para>
+
+ <para>
+
+ This makes sure the the two
+ <application>./build</application> steps are run sequentially,
+ even withthe <filename>--jobs=2</filename> in the command line:
+
+ </para>
+
+ <scons_output example="SideEffectShared">
+    <scons_output_command>scons -Q --jobs=2</scons_output_command>
+ </scons_output>
+
+ <para>
+
+ The &SideEffect; function can be called multiple
+ times for the same side-effect file.
+ Additionally, the name used as a &SideEffect; does not
+ even need to actually exist as a file on disk.
+ &SCons; will still make sure
+ that the relevant targets
+ will be executed sequentially, not in parallel:
+
+ </para>
+
+ <scons_example name="SideEffectParallel">
+   <file name="SConstruct" printme="1">
+    env = Environment()
+    f1 = env.Command('file1.out', [], 'echo >$TARGET data1')
+    env.SideEffect('not_really_updated', f1)
+    f2 = env.Command('file2.out', [], 'echo >$TARGET data2')
+    env.SideEffect('not_really_updated', f2)
+   </file>
+ </scons_example>
+
+ <scons_output example="SideEffectParallel">
+    <scons_output_command>scons -Q --jobs=2</scons_output_command>
+ </scons_output>
+
+ <para>
+
+ Note that it might be tempting to
+ use &SideEffect; for additional target files
+ that a command produces.
+ For example, versions the Microsoft Visual C/C++ compiler
+ produce a <filename>foo.ilk</filename>
+ alongside compiling <filename>foo.obj</filename> file.
+ Specifying <filename>foo.ilk</filename> as a
+ side-effect of <filename>foo.obj</filename>
+ is <emphasis>not</emphasis> a recommended use of &SideEffect;,
+ because &SCons; handle side-effect files
+ slightly differently in its analysis of the dependency graph.
+ When a command produces multiple output files,
+ they should be specified as multiple targets of
+ the call to the relevant builder function,
+ and the &SideEffect; function itself should really only be used
+ when it's important to ensure that commands are not executed in parallel,
+ such as when a "peripheral" file (such as a log file)
+ may actually updated by more than one command invocation.
+
+ </para>
diff --git a/doc/user/sideeffect.xml b/doc/user/sideeffect.xml
new file mode 100644
index 0000000..df62eca
--- /dev/null
+++ b/doc/user/sideeffect.xml
@@ -0,0 +1,211 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <!--
+
+ <para>
+
+ If &SCons; is unaware that a build step produces an extra file,
+ the &SideEffect; method can be used to identify it,
+ so that the file can be used as a dependency in subsequent build steps.
+ However, the primary use for the &SideEffect; method
+ is to prevent two build steps from simultaneously modifying the same file.
+
+ </para>
+
+ TODO: currently doesn't work due to issue #2154:
+ http://scons.tigris.org/issues/show_bug.cgi?id=2154
+
+ <para>
+
+ If more than one build step creates or manipulates the same file,
+ it can cause unpleasant results if both build steps are run at the same time.
+ The shared file is declared as a side-effect of building the primary targets
+ and &SCons; will prevent the two build steps from running in parallel.
+
+ </para>
+
+ <para>
+
+ In this example, the <filename>SConscript</filename> uses
+ &SideEffect; to inform &SCons; about the additional output file.
+
+ </para>
+
+ <scons_example name="SideEffectSimple">
+   <file name="SConstruct" printme="1">
+    env = Environment()
+    f2 = env.Command('file2', 'log', Copy('$TARGET', '$SOURCE'))
+    f1 = env.Command('file1', [],
+        'echo >$TARGET data1; echo >log updated file1'))
+    env.SideEffect('log', env.Command('file1', [],
+        'echo >$TARGET data1; echo >log updated file1'))
+   </file>
+ </scons_example>
+
+ <para>
+
+ Even when run in parallel mode, &SCons; will run the two steps in order:
+
+ </para>
+
+ <scons_output example="SideEffectSimple">
+    <scons_output_command>scons -Q --jobs=2</scons_output_command>
+ </scons_output>
+
+ -->
+
+ <para>
+
+ Sometimes a program the you need to call
+ to build a target file
+ will also update another file,
+ such as a log file describing what the program
+ does while building the target.
+ For example, we the folowing configuration
+ would have &SCons; invoke a hypothetical
+ script named <application>build</application>
+ (in the local directory)
+ with command-line arguments that write
+ log information to a common
+ <filename>logfile.txt</filename> file:
+
+ </para>
+
+ <screen>
+ env = Environment()
+ env.Command('file1.out', 'file.in',
+             './build --log logfile.txt $SOURCE $TARGET')
+ env.Command('file2.out', 'file.in',
+             './build --log logfile.txt $SOURCE $TARGET')
+ <screen>
+
+ <para>
+
+ This can cause problems when running
+ the build in parallel if
+ &SCons; decides to update both targets
+ by running both program invocations at the same time.
+ The multiple program invocations
+ may interfere with each other
+ writing to the common log file,
+ leading at best to intermixed output in the log file,
+ and at worst to an actual failed build
+ (on a system like Windows, for example,
+ where only one process at a time can open the log file for writing).
+
+ </para>
+
+ <para>
+
+ We can make sure that &SCons; does not
+ run these <application>build</application>
+ commands at the same time
+ by using the &SideEffect; function
+ to specify that updating
+ the <filename>logfile.txt</filename> file
+ is a side effect of building the specified
+ <filename>file1</filename>
+ and
+ <filename>file2</filename>
+ target files:
+
+ </para>
+
+ <programlisting>
+   env = Environment()
+   f1 = env.Command('file1.out', 'file1.in',
+                    './build --log logfile.txt $SOURCE $TARGET')
+   f2 = env.Command('file2.out', 'file2.in',
+                    './build --log logfile.txt $SOURCE $TARGET')
+   env.SideEffect('logfile.txt', f1 + f2)
+ </programlisting>
+
+ <para>
+
+ </para>
+
+ <para>
+
+ This makes sure the the two
+ <application>./build</application> steps are run sequentially,
+ even withthe <filename>--jobs=2</filename> in the command line:
+
+ </para>
+
+ <screen>
+    % <userinput>scons -Q --jobs=2</userinput>
+    ./build --log logfile.txt file1.in file1.out
+    ./build --log logfile.txt file2.in file2.out
+ </screen>
+
+ <para>
+
+ The &SideEffect; function can be called multiple
+ times for the same side-effect file.
+ Additionally, the name used as a &SideEffect; does not
+ even need to actually exist as a file on disk.
+ &SCons; will still make sure
+ that the relevant targets
+ will be executed sequentially, not in parallel:
+
+ </para>
+
+ <programlisting>
+    env = Environment()
+    f1 = env.Command('file1.out', [], 'echo &gt;$TARGET data1')
+    env.SideEffect('not_really_updated', f1)
+    f2 = env.Command('file2.out', [], 'echo &gt;$TARGET data2')
+    env.SideEffect('not_really_updated', f2)
+ </programlisting>
+
+ <screen>
+    % <userinput>scons -Q --jobs=2</userinput>
+    echo &gt; file1.out data1
+    echo &gt; file2.out data2
+ </screen>
+
+ <para>
+
+ Note that it might be tempting to
+ use &SideEffect; for additional target files
+ that a command produces.
+ For example, versions the Microsoft Visual C/C++ compiler
+ produce a <filename>foo.ilk</filename>
+ alongside compiling <filename>foo.obj</filename> file.
+ Specifying <filename>foo.ilk</filename> as a
+ side-effect of <filename>foo.obj</filename>
+ is <emphasis>not</emphasis> a recommended use of &SideEffect;,
+ because &SCons; handle side-effect files
+ slightly differently in its analysis of the dependency graph.
+ When a command produces multiple output files,
+ they should be specified as multiple targets of
+ the call to the relevant builder function,
+ and the &SideEffect; function itself should really only be used
+ when it's important to ensure that commands are not executed in parallel,
+ such as when a "peripheral" file (such as a log file)
+ may actually updated by more than one command invocation.
+
+ </para>
diff --git a/doc/user/simple.in b/doc/user/simple.in
new file mode 100644
index 0000000..4d42934
--- /dev/null
+++ b/doc/user/simple.in
@@ -0,0 +1,517 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+ In this chapter,
+ you will see several examples of
+ very simple build configurations using &SCons;,
+ which will demonstrate how easy
+ it is to use &SCons; to
+ build programs from several different programming languages
+ on different types of systems.
+
+ </para>
+
+ <section>
+ <title>Building Simple C / C++ Programs</title>
+
+   <para>
+
+   Here's the famous "Hello, World!" program in C:
+
+   </para>
+
+   <programlisting>
+      int
+      main()
+      {
+          printf("Hello, world!\n");
+      }
+   </programlisting>
+
+   <para>
+
+   And here's how to build it using &SCons;.
+   Enter the following into a file named &SConstruct;:
+
+   </para>
+
+   <scons_example name="ex1">
+      <file name="SConstruct" printme="1">
+      Program('hello.c')
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+   </scons_example>
+
+   <para>
+
+   This minimal configuration file gives
+   &SCons; two pieces of information:
+   what you want to build
+   (an executable program),
+   and the input file from
+   which you want it built
+   (the <filename>hello.c</filename> file).
+   &b-link-Program; is a <firstterm>builder_method</firstterm>,
+   a Python call that tells &SCons; that you want to build an
+   executable program.
+
+   </para>
+
+   <para>
+
+   That's it.  Now run the &scons; command to build the program.
+   On a POSIX-compliant system like Linux or UNIX,
+   you'll see something like:
+
+   </para>
+
+   <scons_output example="ex1" os="posix">
+      <scons_output_command>scons</scons_output_command>
+   </scons_output>
+
+   <para>
+
+   On a Windows system with the Microsoft Visual C++ compiler,
+   you'll see something like:
+
+   </para>
+
+   <scons_output example="ex1" os="win32">
+      <scons_output_command>scons</scons_output_command>
+   </scons_output>
+
+   <para>
+
+   First, notice that you only need
+   to specify the name of the source file,
+   and that &SCons; correctly deduces the names of
+   the object and executable files to be built
+   from the base of the source file name.
+
+   </para>
+
+   <para>
+
+   Second, notice that the same input &SConstruct; file,
+   without any changes,
+   generates the correct output file names on both systems:
+   <filename>hello.o</filename> and <filename>hello</filename>
+   on POSIX systems,
+   <filename>hello.obj</filename> and <filename>hello.exe</filename>
+   on Windows systems.
+   This is a simple example of how &SCons;
+   makes it extremely easy to
+   write portable software builds.
+
+   </para>
+
+   <para>
+
+   (Note that we won't provide duplicate side-by-side
+   POSIX and Windows output for all of the examples in this guide;
+   just keep in mind that, unless otherwise specified,
+   any of the examples should work equally well on both types of systems.)
+
+   </para>
+
+ </section>
+
+ <section>
+ <title>Building Object Files</title>
+
+   <para>
+
+   The &b-link-Program; builder method is only one of
+   many builder methods that &SCons; provides
+   to build different types of files.
+   Another is the &b-link-Object; builder method,
+   which tells &SCons; to build an object file
+   from the specified source file:
+
+   </para>
+
+   <scons_example name="Object">
+      <file name="SConstruct" printme="1">
+      Object('hello.c')
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+   </scons_example>
+
+   <para>
+
+   Now when you run the &scons; command to build the program,
+   it will build just the &hello_o; object file on a POSIX system:
+
+   </para>
+
+   <scons_output example="Object" os="posix">
+      <scons_output_command>scons</scons_output_command>
+   </scons_output>
+
+   <para>
+
+   And just the &hello_obj; object file
+   on a Windows system (with the Microsoft Visual C++ compiler):
+
+   </para>
+
+   <scons_output example="Object" os="win32">
+      <scons_output_command>scons</scons_output_command>
+   </scons_output>
+
+ </section>
+
+ <section>
+ <title>Simple Java Builds</title>
+
+   <para>
+
+   &SCons; also makes building with Java extremely easy.
+   Unlike the &b-link-Program; and &b-link-Object; builder methods,
+   however, the &b-link-Java; builder method
+   requires that you specify
+   the name of a destination directory in which
+   you want the class files placed,
+   followed by the source directory
+   in which the <filename>.java</filename> files live:
+
+   </para>
+
+   <scons_example name="java">
+     <file name="SConstruct" printme="1">
+     Java('classes', 'src')
+     </file>
+     <file name="src/hello.java">
+     public class Example1
+     {
+       public static void main(String[] args)
+       {
+         System.out.println("Hello Java world!\n");
+       }
+     }
+     </file>
+   </scons_example>
+
+   <para>
+
+   If the <filename>src</filename> directory
+   contains a single <filename>hello.java</filename> file,
+   then the output from running the &scons; command
+   would look something like this
+   (on a POSIX system):
+
+   </para>
+
+   <scons_output example="java" os="posix">
+      <scons_output_command>scons</scons_output_command>
+   </scons_output>
+
+   <para>
+
+   We'll cover Java builds in more detail,
+   including building Java archive (<filename>.jar</filename>)
+   and other types of file,
+   in <xref linkend="chap-java"></xref>.
+
+   </para>
+
+ </section>
+
+ <section>
+ <title>Cleaning Up After a Build</title>
+
+   <para>
+
+   When using &SCons;, it is unnecessary to add special
+   commands or target names to clean up after a build.
+   Instead, you simply use the
+   <literal>-c</literal> or <literal>--clean</literal>
+   option when you invoke &SCons;,
+   and &SCons; removes the appropriate built files.
+   So if we build our example above
+   and then invoke <literal>scons -c</literal>
+   afterwards, the output on POSIX looks like:
+
+   </para>
+
+   <scons_example name="clean">
+      <file name="SConstruct">
+      Program('hello.c')
+      </file>
+      <file name="hello.c">
+      int main() { printf("Hello, world!\n"); }
+      </file>
+   </scons_example>
+
+   <scons_output example="clean" os="posix">
+      <scons_output_command>scons</scons_output_command>
+      <scons_output_command>scons -c</scons_output_command>
+   </scons_output>
+
+   <para>
+
+   And the output on Windows looks like:
+
+   </para>
+
+   <scons_output example="clean" os="win32">
+      <scons_output_command>scons</scons_output_command>
+      <scons_output_command>scons -c</scons_output_command>
+   </scons_output>
+
+   <para>
+
+   Notice that &SCons; changes its output to tell you that it
+   is <literal>Cleaning targets ...</literal> and
+   <literal>done cleaning targets.</literal>
+
+   </para>
+
+ </section>
+
+ <section>
+ <title>The &SConstruct; File</title>
+
+   <para>
+
+   If you're used to build systems like &Make;
+   you've already figured out that the &SConstruct; file
+   is the &SCons; equivalent of a &Makefile;.
+   That is, the &SConstruct; file is the input file
+   that &SCons; reads to control the build.
+
+   </para>
+
+   <section>
+   <title>&SConstruct; Files Are Python Scripts</title>
+
+     <para>
+
+     There is, however, an important difference between
+     an &SConstruct; file and a &Makefile;:
+     the &SConstruct; file is actually a Python script.
+     If you're not already familiar with Python, don't worry.
+     This User's Guide will introduce you step-by-step
+     to the relatively small amount of Python you'll
+     need to know to be able to use &SCons; effectively.
+     And Python is very easy to learn.
+
+     </para>
+
+     <para>
+
+     One aspect of using Python as the
+     scripting language is that you can put comments
+     in your &SConstruct; file using Python's commenting convention;
+     that is, everything between a '#' and the end of the line
+     will be ignored:
+
+     </para>
+
+     <programlisting>
+        # Arrange to build the "hello" program.
+        Program('hello.c')    # "hello.c" is the source file.
+     </programlisting>
+
+     <para>
+
+     You'll see throughout the remainder of this Guide
+     that being able to use the power of a
+     real scripting language
+     can greatly simplify the solutions
+     to complex requirements of real-world builds.
+
+     </para>
+
+   </section>
+
+   <section>
+   <title>&SCons; Functions Are Order-Independent</title>
+
+     <para>
+
+     One important way in which the &SConstruct;
+     file is not exactly like a normal Python script,
+     and is more like a &Makefile,
+     is that the order in which
+     the &SCons; functions are called in
+     the &SConstruct; file
+     does <emphasis>not</emphasis>
+     affect the order in which &SCons;
+     actually builds the programs and object files
+     you want it to build.<footnote>
+     <para>In programming parlance,
+     the &SConstruct; file is
+     <emphasis>declarative</emphasis>,
+     meaning you tell &SCons; what you want done
+     and let it figure out the order in which to do it,
+     rather than strictly <emphasis>imperative</emphasis>,
+     where you specify explicitly the order in
+     which to do things.
+     </para>
+     </footnote>
+     In other words, when you call the &b-link-Program; builder
+     (or any other builder method),
+     you're not telling &SCons; to build
+     the program at the instant the builder method is called.
+     Instead, you're telling &SCons; to build the program
+     that you want, for example,
+     a program built from a file named &hello_c;,
+     and it's up to &SCons; to build that program
+     (and any other files) whenever it's necessary.
+     (We'll learn more about how
+     &SCons; decides when building or rebuilding a file
+     is necessary in <xref linkend="chap-depends"></xref>, below.)
+ 
+     </para>
+ 
+     <para>
+
+     &SCons; reflects this distinction between
+     <emphasis>calling a builder method like</emphasis> &b-Program;
+     and <emphasis>actually building the program</emphasis>
+     by printing the status messages that indicate
+     when it's "just reading" the &SConstruct; file,
+     and when it's actually building the target files.
+     This is to make it clear when &SCons; is
+     executing the Python statements that make up the &SConstruct; file,
+     and when &SCons; is actually executing the
+     commands or other actions to
+     build the necessary files.
+
+     </para>
+
+     <para>
+
+     Let's clarify this with an example.
+     Python has a <literal>print</literal> statement that
+     prints a string of characters to the screen.
+     If we put <literal>print</literal> statements around
+     our calls to the &b-Program; builder method:
+
+     </para>
+
+     <scons_example name="declarative">
+       <file name="SConstruct" printme="1">
+       print "Calling Program('hello.c')"
+       Program('hello.c')
+       print "Calling Program('goodbye.c')"
+       Program('goodbye.c')
+       print "Finished calling Program()"
+       </file>
+       <file name="hello.c">
+       int main() { printf("Hello, world!\n"); }
+       </file>
+       <file name="goodbye.c">
+       int main() { printf("Goodbye, world!\n"); }
+       </file>
+     </scons_example>
+
+     <para>
+
+     Then when we execute &SCons;,
+     we see the output from the <literal>print</literal>
+     statements in between the messages about
+     reading the &SConscript; files,
+     indicating that that is when the
+     Python statements are being executed:
+
+     </para>
+
+     <scons_output example="declarative" os="posix">
+       <scons_output_command>scons</scons_output_command>
+     </scons_output>
+
+     <para>
+
+     Notice also that &SCons; built the &goodbye; program first,
+     even though the "reading &SConscript" output
+     shows that we called <literal>Program('hello.c')</literal>
+     first in the &SConstruct; file.
+
+     </para>
+
+   </section>
+
+ </section>
+
+ <section>
+ <title>Making the &SCons; Output Less Verbose</title>
+
+   <para>
+
+   You've already seen how &SCons; prints
+   some messages about what it's doing,
+   surrounding the actual commands used to build the software:
+
+   </para>
+
+   <scons_output example="ex1" os="win32">
+      <scons_output_command>scons</scons_output_command>
+   </scons_output>
+
+   <para>
+
+   These messages emphasize the
+   order in which &SCons; does its work:
+   all of the configuration files
+   (generically referred to as &SConscript; files)
+   are read and executed first,
+   and only then are the target files built.
+   Among other benefits, these messages help to distinguish between
+   errors that occur while the configuration files are read,
+   and errors that occur while targets are being built.
+
+   </para>
+
+   <para>
+
+   One drawback, of course, is that these messages clutter the output.
+   Fortunately, they're easily disabled by using
+   the &Q; option when invoking &SCons;:
+
+   </para>
+
+   <scons_output example="ex1" os="win32">
+      <scons_output_command>scons -Q</scons_output_command>
+   </scons_output>
+
+   <para>
+
+   Because we want this User's Guide to focus
+   on what &SCons; is actually doing,
+   we're going to use the &Q; option
+   to remove these messages from the
+   output of all the remaining examples in this Guide.
+
+   </para>
+
+ </section>
diff --git a/doc/user/simple.xml b/doc/user/simple.xml
new file mode 100644
index 0000000..598d44b
--- /dev/null
+++ b/doc/user/simple.xml
@@ -0,0 +1,587 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+ <para>
+
+ In this chapter,
+ you will see several examples of
+ very simple build configurations using &SCons;,
+ which will demonstrate how easy
+ it is to use &SCons; to
+ build programs from several different programming languages
+ on different types of systems.
+
+ </para>
+
+ <section>
+ <title>Building Simple C / C++ Programs</title>
+
+   <para>
+
+   Here's the famous "Hello, World!" program in C:
+
+   </para>
+
+   <programlisting>
+      int
+      main()
+      {
+          printf("Hello, world!\n");
+      }
+   </programlisting>
+
+   <para>
+
+   And here's how to build it using &SCons;.
+   Enter the following into a file named &SConstruct;:
+
+   </para>
+
+   <programlisting>
+      Program('hello.c')
+   </programlisting>
+
+   <para>
+
+   This minimal configuration file gives
+   &SCons; two pieces of information:
+   what you want to build
+   (an executable program),
+   and the input file from
+   which you want it built
+   (the <filename>hello.c</filename> file).
+   &b-link-Program; is a <firstterm>builder_method</firstterm>,
+   a Python call that tells &SCons; that you want to build an
+   executable program.
+
+   </para>
+
+   <para>
+
+   That's it.  Now run the &scons; command to build the program.
+   On a POSIX-compliant system like Linux or UNIX,
+   you'll see something like:
+
+   </para>
+
+   <screen>
+      % <userinput>scons</userinput>
+      scons: Reading SConscript files ...
+      scons: done reading SConscript files.
+      scons: Building targets ...
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+      scons: done building targets.
+   </screen>
+
+   <para>
+
+   On a Windows system with the Microsoft Visual C++ compiler,
+   you'll see something like:
+
+   </para>
+
+   <screen>
+      C:\><userinput>scons</userinput>
+      scons: Reading SConscript files ...
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      scons: done reading SConscript files.
+      scons: Building targets ...
+      cl /Fohello.obj /c hello.c /nologo
+      link /nologo /OUT:hello.exe hello.obj
+      scons: done building targets.
+   </screen>
+
+   <para>
+
+   First, notice that you only need
+   to specify the name of the source file,
+   and that &SCons; correctly deduces the names of
+   the object and executable files to be built
+   from the base of the source file name.
+
+   </para>
+
+   <para>
+
+   Second, notice that the same input &SConstruct; file,
+   without any changes,
+   generates the correct output file names on both systems:
+   <filename>hello.o</filename> and <filename>hello</filename>
+   on POSIX systems,
+   <filename>hello.obj</filename> and <filename>hello.exe</filename>
+   on Windows systems.
+   This is a simple example of how &SCons;
+   makes it extremely easy to
+   write portable software builds.
+
+   </para>
+
+   <para>
+
+   (Note that we won't provide duplicate side-by-side
+   POSIX and Windows output for all of the examples in this guide;
+   just keep in mind that, unless otherwise specified,
+   any of the examples should work equally well on both types of systems.)
+
+   </para>
+
+ </section>
+
+ <section>
+ <title>Building Object Files</title>
+
+   <para>
+
+   The &b-link-Program; builder method is only one of
+   many builder methods that &SCons; provides
+   to build different types of files.
+   Another is the &b-link-Object; builder method,
+   which tells &SCons; to build an object file
+   from the specified source file:
+
+   </para>
+
+   <programlisting>
+      Object('hello.c')
+   </programlisting>
+
+   <para>
+
+   Now when you run the &scons; command to build the program,
+   it will build just the &hello_o; object file on a POSIX system:
+
+   </para>
+
+   <screen>
+      % <userinput>scons</userinput>
+      scons: Reading SConscript files ...
+      scons: done reading SConscript files.
+      scons: Building targets ...
+      cc -o hello.o -c hello.c
+      scons: done building targets.
+   </screen>
+
+   <para>
+
+   And just the &hello_obj; object file
+   on a Windows system (with the Microsoft Visual C++ compiler):
+
+   </para>
+
+   <screen>
+      C:\><userinput>scons</userinput>
+      scons: Reading SConscript files ...
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      scons: done reading SConscript files.
+      scons: Building targets ...
+      cl /Fohello.obj /c hello.c /nologo
+      scons: done building targets.
+   </screen>
+
+ </section>
+
+ <section>
+ <title>Simple Java Builds</title>
+
+   <para>
+
+   &SCons; also makes building with Java extremely easy.
+   Unlike the &b-link-Program; and &b-link-Object; builder methods,
+   however, the &b-link-Java; builder method
+   requires that you specify
+   the name of a destination directory in which
+   you want the class files placed,
+   followed by the source directory
+   in which the <filename>.java</filename> files live:
+
+   </para>
+
+   <programlisting>
+     Java('classes', 'src')
+   </programlisting>
+
+   <para>
+
+   If the <filename>src</filename> directory
+   contains a single <filename>hello.java</filename> file,
+   then the output from running the &scons; command
+   would look something like this
+   (on a POSIX system):
+
+   </para>
+
+   <screen>
+      % <userinput>scons</userinput>
+      scons: Reading SConscript files ...
+      scons: done reading SConscript files.
+      scons: Building targets ...
+      javac -d classes -sourcepath src src/hello.java
+      scons: done building targets.
+   </screen>
+
+   <para>
+
+   We'll cover Java builds in more detail,
+   including building Java archive (<filename>.jar</filename>)
+   and other types of file,
+   in <xref linkend="chap-java"></xref>.
+
+   </para>
+
+ </section>
+
+ <section>
+ <title>Cleaning Up After a Build</title>
+
+   <para>
+
+   When using &SCons;, it is unnecessary to add special
+   commands or target names to clean up after a build.
+   Instead, you simply use the
+   <literal>-c</literal> or <literal>--clean</literal>
+   option when you invoke &SCons;,
+   and &SCons; removes the appropriate built files.
+   So if we build our example above
+   and then invoke <literal>scons -c</literal>
+   afterwards, the output on POSIX looks like:
+
+   </para>
+
+   
+
+   <screen>
+      % <userinput>scons</userinput>
+      scons: Reading SConscript files ...
+      scons: done reading SConscript files.
+      scons: Building targets ...
+      cc -o hello.o -c hello.c
+      cc -o hello hello.o
+      scons: done building targets.
+      % <userinput>scons -c</userinput>
+      scons: Reading SConscript files ...
+      scons: done reading SConscript files.
+      scons: Cleaning targets ...
+      Removed hello.o
+      Removed hello
+      scons: done cleaning targets.
+   </screen>
+
+   <para>
+
+   And the output on Windows looks like:
+
+   </para>
+
+   <screen>
+      C:\><userinput>scons</userinput>
+      scons: Reading SConscript files ...
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      scons: done reading SConscript files.
+      scons: Building targets ...
+      cl /Fohello.obj /c hello.c /nologo
+      link /nologo /OUT:hello.exe hello.obj
+      scons: done building targets.
+      C:\><userinput>scons -c</userinput>
+      scons: Reading SConscript files ...
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      scons: done reading SConscript files.
+      scons: Cleaning targets ...
+      Removed hello.obj
+      Removed hello.exe
+      scons: done cleaning targets.
+   </screen>
+
+   <para>
+
+   Notice that &SCons; changes its output to tell you that it
+   is <literal>Cleaning targets ...</literal> and
+   <literal>done cleaning targets.</literal>
+
+   </para>
+
+ </section>
+
+ <section>
+ <title>The &SConstruct; File</title>
+
+   <para>
+
+   If you're used to build systems like &Make;
+   you've already figured out that the &SConstruct; file
+   is the &SCons; equivalent of a &Makefile;.
+   That is, the &SConstruct; file is the input file
+   that &SCons; reads to control the build.
+
+   </para>
+
+   <section>
+   <title>&SConstruct; Files Are Python Scripts</title>
+
+     <para>
+
+     There is, however, an important difference between
+     an &SConstruct; file and a &Makefile;:
+     the &SConstruct; file is actually a Python script.
+     If you're not already familiar with Python, don't worry.
+     This User's Guide will introduce you step-by-step
+     to the relatively small amount of Python you'll
+     need to know to be able to use &SCons; effectively.
+     And Python is very easy to learn.
+
+     </para>
+
+     <para>
+
+     One aspect of using Python as the
+     scripting language is that you can put comments
+     in your &SConstruct; file using Python's commenting convention;
+     that is, everything between a '#' and the end of the line
+     will be ignored:
+
+     </para>
+
+     <programlisting>
+        # Arrange to build the "hello" program.
+        Program('hello.c')    # "hello.c" is the source file.
+     </programlisting>
+
+     <para>
+
+     You'll see throughout the remainder of this Guide
+     that being able to use the power of a
+     real scripting language
+     can greatly simplify the solutions
+     to complex requirements of real-world builds.
+
+     </para>
+
+   </section>
+
+   <section>
+   <title>&SCons; Functions Are Order-Independent</title>
+
+     <para>
+
+     One important way in which the &SConstruct;
+     file is not exactly like a normal Python script,
+     and is more like a &Makefile;,
+     is that the order in which
+     the &SCons; functions are called in
+     the &SConstruct; file
+     does <emphasis>not</emphasis>
+     affect the order in which &SCons;
+     actually builds the programs and object files
+     you want it to build.<footnote>
+     <para>In programming parlance,
+     the &SConstruct; file is
+     <emphasis>declarative</emphasis>,
+     meaning you tell &SCons; what you want done
+     and let it figure out the order in which to do it,
+     rather than strictly <emphasis>imperative</emphasis>,
+     where you specify explicitly the order in
+     which to do things.
+     </para>
+     </footnote>
+     In other words, when you call the &b-link-Program; builder
+     (or any other builder method),
+     you're not telling &SCons; to build
+     the program at the instant the builder method is called.
+     Instead, you're telling &SCons; to build the program
+     that you want, for example,
+     a program built from a file named &hello_c;,
+     and it's up to &SCons; to build that program
+     (and any other files) whenever it's necessary.
+     (We'll learn more about how
+     &SCons; decides when building or rebuilding a file
+     is necessary in <xref linkend="chap-depends"></xref>, below.)
+ 
+     </para>
+ 
+     <para>
+
+     &SCons; reflects this distinction between
+     <emphasis>calling a builder method like</emphasis> &b-Program;
+     and <emphasis>actually building the program</emphasis>
+     by printing the status messages that indicate
+     when it's "just reading" the &SConstruct; file,
+     and when it's actually building the target files.
+     This is to make it clear when &SCons; is
+     executing the Python statements that make up the &SConstruct; file,
+     and when &SCons; is actually executing the
+     commands or other actions to
+     build the necessary files.
+
+     </para>
+
+     <para>
+
+     Let's clarify this with an example.
+     Python has a <literal>print</literal> statement that
+     prints a string of characters to the screen.
+     If we put <literal>print</literal> statements around
+     our calls to the &b-Program; builder method:
+
+     </para>
+
+     <programlisting>
+       print "Calling Program('hello.c')"
+       Program('hello.c')
+       print "Calling Program('goodbye.c')"
+       Program('goodbye.c')
+       print "Finished calling Program()"
+     </programlisting>
+
+     <para>
+
+     Then when we execute &SCons;,
+     we see the output from the <literal>print</literal>
+     statements in between the messages about
+     reading the &SConscript; files,
+     indicating that that is when the
+     Python statements are being executed:
+
+     </para>
+
+     <screen>
+       % <userinput>scons</userinput>
+       scons: Reading SConscript files ...
+       Calling Program('hello.c')
+       Calling Program('goodbye.c')
+       Finished calling Program()
+       scons: done reading SConscript files.
+       scons: Building targets ...
+       cc -o goodbye.o -c goodbye.c
+       cc -o goodbye goodbye.o
+       cc -o hello.o -c hello.c
+       cc -o hello hello.o
+       scons: done building targets.
+     </screen>
+
+     <para>
+
+     Notice also that &SCons; built the &goodbye; program first,
+     even though the "reading &SConscript;" output
+     shows that we called <literal>Program('hello.c')</literal>
+     first in the &SConstruct; file.
+
+     </para>
+
+   </section>
+
+ </section>
+
+ <section>
+ <title>Making the &SCons; Output Less Verbose</title>
+
+   <para>
+
+   You've already seen how &SCons; prints
+   some messages about what it's doing,
+   surrounding the actual commands used to build the software:
+
+   </para>
+
+   <screen>
+      C:\><userinput>scons</userinput>
+      scons: Reading SConscript files ...
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      scons: done reading SConscript files.
+      scons: Building targets ...
+      cl /Fohello.obj /c hello.c /nologo
+      link /nologo /OUT:hello.exe hello.obj
+      scons: done building targets.
+   </screen>
+
+   <para>
+
+   These messages emphasize the
+   order in which &SCons; does its work:
+   all of the configuration files
+   (generically referred to as &SConscript; files)
+   are read and executed first,
+   and only then are the target files built.
+   Among other benefits, these messages help to distinguish between
+   errors that occur while the configuration files are read,
+   and errors that occur while targets are being built.
+
+   </para>
+
+   <para>
+
+   One drawback, of course, is that these messages clutter the output.
+   Fortunately, they're easily disabled by using
+   the &Q; option when invoking &SCons;:
+
+   </para>
+
+   <screen>
+      C:\><userinput>scons -Q</userinput>
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      cl /Fohello.obj /c hello.c /nologo
+      link /nologo /OUT:hello.exe hello.obj
+   </screen>
+
+   <para>
+
+   Because we want this User's Guide to focus
+   on what &SCons; is actually doing,
+   we're going to use the &Q; option
+   to remove these messages from the
+   output of all the remaining examples in this Guide.
+
+   </para>
+
+ </section>
diff --git a/doc/user/sourcecode.in b/doc/user/sourcecode.in
new file mode 100644
index 0000000..5cbbe1a
--- /dev/null
+++ b/doc/user/sourcecode.in
@@ -0,0 +1,162 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+-->
+
+ <para>
+
+   XXX
+
+ </para>
+
+ <section>
+ <title>Fetching Source Code From BitKeeper</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+   <scons_example name="ex_bitkeeper">
+      <file name="SConstruct" printme="1">
+      env = Environment()
+      env.SourceCode('.', env.BitKeeper())
+      env.Program('hello.c')
+      </file>
+      <file name="s.hello.c">
+      s.hello.c
+      </file>
+   </scons_example>
+
+   <scons_output example="ex_bitkeeper">
+     <scons_output_command>scons -Q</scons_output_command>
+   </scons_output>
+
+ </section>
+
+ <section>
+ <title>Fetching Source Code From CVS</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+   <scons_example name="ex_cvs">
+      <file name="SConstruct" printme="1">
+      env = Environment()
+      env.SourceCode('.', env.CVS('/usr/local/CVS'))
+      env.Program('hello.c')
+      </file>
+   </scons_example>
+
+   <scons_output example="ex_cvs">
+     <scons_output_command>scons -Q</scons_output_command>
+   </scons_output>
+
+ </section>
+
+ <section>
+ <title>Fetching Source Code From RCS</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+   <scons_example name="ex_rcs">
+      <file name="SConstruct" printme="1">
+      env = Environment()
+      env.SourceCode('.', env.RCS())
+      env.Program('hello.c')
+      </file>
+      <file name="hello.c,v">
+      hello.c,v
+      </file>
+   </scons_example>
+
+   <scons_output example="ex_rcs">
+     <scons_output_command>scons -Q</scons_output_command>
+   </scons_output>
+
+ </section>
+
+ <section>
+ <title>Fetching Source Code From SCCS</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+   <scons_example name="ex_sccs">
+      <file name="SConstruct" printme="1">
+      env = Environment()
+      env.SourceCode('.', env.SCCS())
+      env.Program('hello.c')
+      </file>
+      <file name="s.hello.c">
+      s.hello.c
+      </file>
+   </scons_example>
+
+   <scons_output example="ex_sccs">
+     <scons_output_command>scons -Q</scons_output_command>
+   </scons_output>
+
+ </section>
+
+ <!--
+
+ <section>
+ <title>Fetching Source Code From Subversion</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+   <scons_example name="ex_subversion">
+      <file name="SConstruct" printme="1">
+      env = Environment()
+      env.SourceCode('.', env.Subversion('XXX'))
+      env.Program('hello.c')
+      </file>
+   </scons_example>
+
+   <scons_output example="ex_subversion">
+     <scons_output_command>scons -Q</scons_output_command>
+   </scons_output>
+
+ </section>
+
+ -->
diff --git a/doc/user/sourcecode.xml b/doc/user/sourcecode.xml
new file mode 100644
index 0000000..aebcd20
--- /dev/null
+++ b/doc/user/sourcecode.xml
@@ -0,0 +1,157 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+-->
+
+ <para>
+
+   XXX
+
+ </para>
+
+ <section>
+ <title>Fetching Source Code From BitKeeper</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+   <programlisting>
+      env = Environment()
+      env.SourceCode('.', env.BitKeeper())
+      env.Program('hello.c')
+   </programlisting>
+
+   <screen>
+     % <userinput>scons -Q</userinput>
+     bk get hello.c
+     cc -o hello.o -c hello.c
+     cc -o hello hello.o
+   </screen>
+
+ </section>
+
+ <section>
+ <title>Fetching Source Code From CVS</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+   <programlisting>
+      env = Environment()
+      env.SourceCode('.', env.CVS('/usr/local/CVS'))
+      env.Program('hello.c')
+   </programlisting>
+
+   <screen>
+     % <userinput>scons -Q</userinput>
+     cvs -d /usr/local/CVS co hello.c
+     cc -o hello.o -c hello.c
+     cc -o hello hello.o
+   </screen>
+
+ </section>
+
+ <section>
+ <title>Fetching Source Code From RCS</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+   <programlisting>
+      env = Environment()
+      env.SourceCode('.', env.RCS())
+      env.Program('hello.c')
+   </programlisting>
+
+   <screen>
+     % <userinput>scons -Q</userinput>
+     co hello.c
+     cc -o hello.o -c hello.c
+     cc -o hello hello.o
+   </screen>
+
+ </section>
+
+ <section>
+ <title>Fetching Source Code From SCCS</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+   <programlisting>
+      env = Environment()
+      env.SourceCode('.', env.SCCS())
+      env.Program('hello.c')
+   </programlisting>
+
+   <screen>
+     % <userinput>scons -Q</userinput>
+     sccs get hello.c
+     cc -o hello.o -c hello.c
+     cc -o hello hello.o
+   </screen>
+
+ </section>
+
+ <!--
+
+ <section>
+ <title>Fetching Source Code From Subversion</title>
+
+   <para>
+
+   XXX
+
+   </para>
+
+   <scons_example name="ex_subversion">
+      <file name="SConstruct" printme="1">
+      env = Environment()
+      env.SourceCode('.', env.Subversion('XXX'))
+      env.Program('hello.c')
+      </file>
+   </scons_example>
+
+   <scons_output example="ex_subversion">
+     <scons_output_command>scons -Q</scons_output_command>
+   </scons_output>
+
+ </section>
+
+ -->
diff --git a/doc/user/tasks.in b/doc/user/tasks.in
new file mode 100644
index 0000000..14775c8
--- /dev/null
+++ b/doc/user/tasks.in
@@ -0,0 +1,108 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<para>
+There is a common set of simple tasks that many build configurations rely
+on as they become more complex. Most build tools have special
+purpose constructs for performing these tasks, but since &SConscript;
+files are &Python; scripts, you can use more flexible built-in &Python;
+services to perform these tasks. This appendix lists a number of these
+tasks and how to implement them in &Python;.
+</para>
+
+<example>
+<title>Wildcard globbing to create a list of filenames</title>
+<programlisting>
+files = Glob(wildcard)
+</programlisting>
+</example>
+
+<example>
+<title>Filename extension substitution</title>
+<programlisting>
+import os.path
+filename = os.path.splitext(filename)[0]+extension
+</programlisting>
+</example>
+
+<example>
+<title>Appending a path prefix to a list of filenames</title>
+<programlisting>
+import os.path
+filenames = [os.path.join(prefix, x) for x in filenames]
+</programlisting>
+
+<simpara>or in Python 1.5.2:</simpara>
+
+<programlisting>
+import os.path
+new_filenames = [] 
+for x in filenames:
+    new_filenames.append(os.path.join(prefix, x))
+</programlisting>
+</example>
+
+<example>
+<title>Substituting a path prefix with another one</title>
+<programlisting>
+if filename.find(old_prefix) == 0:
+    filename = filename.replace(old_prefix, new_prefix)
+</programlisting>
+
+<simpara>or in Python 1.5.2:</simpara>
+
+<programlisting>
+import string
+if string.find(filename, old_prefix) == 0:
+    filename = string.replace(filename, old_prefix, new_prefix)      
+</programlisting>
+</example>
+
+<example>
+<title>Filtering a filename list to exclude/retain only a specific set
+of extensions</title>
+<programlisting>
+import os.path
+filenames = [x for x in filenames if os.path.splitext(x)[1] in extensions]
+</programlisting>
+
+<simpara>or in Python 1.5.2:</simpara>
+
+<programlisting>
+import os.path
+new_filenames = []
+for x in filenames:
+    if os.path.splitext(x)[1] in extensions:
+        new_filenames.append(x)
+</programlisting>
+</example>
+
+<example>
+<title>The "backtick function": run a shell command and capture the
+output</title>
+<programlisting>import os
+output = os.popen(command).read()
+</programlisting>
+</example>
diff --git a/doc/user/tasks.xml b/doc/user/tasks.xml
new file mode 100644
index 0000000..14775c8
--- /dev/null
+++ b/doc/user/tasks.xml
@@ -0,0 +1,108 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<para>
+There is a common set of simple tasks that many build configurations rely
+on as they become more complex. Most build tools have special
+purpose constructs for performing these tasks, but since &SConscript;
+files are &Python; scripts, you can use more flexible built-in &Python;
+services to perform these tasks. This appendix lists a number of these
+tasks and how to implement them in &Python;.
+</para>
+
+<example>
+<title>Wildcard globbing to create a list of filenames</title>
+<programlisting>
+files = Glob(wildcard)
+</programlisting>
+</example>
+
+<example>
+<title>Filename extension substitution</title>
+<programlisting>
+import os.path
+filename = os.path.splitext(filename)[0]+extension
+</programlisting>
+</example>
+
+<example>
+<title>Appending a path prefix to a list of filenames</title>
+<programlisting>
+import os.path
+filenames = [os.path.join(prefix, x) for x in filenames]
+</programlisting>
+
+<simpara>or in Python 1.5.2:</simpara>
+
+<programlisting>
+import os.path
+new_filenames = [] 
+for x in filenames:
+    new_filenames.append(os.path.join(prefix, x))
+</programlisting>
+</example>
+
+<example>
+<title>Substituting a path prefix with another one</title>
+<programlisting>
+if filename.find(old_prefix) == 0:
+    filename = filename.replace(old_prefix, new_prefix)
+</programlisting>
+
+<simpara>or in Python 1.5.2:</simpara>
+
+<programlisting>
+import string
+if string.find(filename, old_prefix) == 0:
+    filename = string.replace(filename, old_prefix, new_prefix)      
+</programlisting>
+</example>
+
+<example>
+<title>Filtering a filename list to exclude/retain only a specific set
+of extensions</title>
+<programlisting>
+import os.path
+filenames = [x for x in filenames if os.path.splitext(x)[1] in extensions]
+</programlisting>
+
+<simpara>or in Python 1.5.2:</simpara>
+
+<programlisting>
+import os.path
+new_filenames = []
+for x in filenames:
+    if os.path.splitext(x)[1] in extensions:
+        new_filenames.append(x)
+</programlisting>
+</example>
+
+<example>
+<title>The "backtick function": run a shell command and capture the
+output</title>
+<programlisting>import os
+output = os.popen(command).read()
+</programlisting>
+</example>
diff --git a/doc/user/tools.in b/doc/user/tools.in
new file mode 100644
index 0000000..cc0628e
--- /dev/null
+++ b/doc/user/tools.in
@@ -0,0 +1,38 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<para>
+
+This appendix contains descriptions of all of the
+Tools modules that are
+available "out of the box" in this version of SCons.
+
+</para>
+
+<variablelist>
+
+&tools-gen;
+
+</variablelist>
diff --git a/doc/user/tools.xml b/doc/user/tools.xml
new file mode 100644
index 0000000..cc0628e
--- /dev/null
+++ b/doc/user/tools.xml
@@ -0,0 +1,38 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<para>
+
+This appendix contains descriptions of all of the
+Tools modules that are
+available "out of the box" in this version of SCons.
+
+</para>
+
+<variablelist>
+
+&tools-gen;
+
+</variablelist>
diff --git a/doc/user/troubleshoot.in b/doc/user/troubleshoot.in
new file mode 100644
index 0000000..c729149
--- /dev/null
+++ b/doc/user/troubleshoot.in
@@ -0,0 +1,875 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  The experience of configuring any
+  software build tool to build a large code base
+  usually, at some point,
+  involves trying to figure out why
+  the tool is behaving a certain way,
+  and how to get it to behave the way you want.
+  &SCons; is no different.
+  This appendix contains a number of
+  different ways in which you can
+  get some additional insight into &SCons' behavior.
+
+  </para>
+
+  <para>
+
+  Note that we're always interested in trying to
+  improve how you can troubleshoot configuration problems.
+  If you run into a problem that has
+  you scratching your head,
+  and which there just doesn't seem to be a good way to debug,
+  odds are pretty good that someone else will run into
+  the same problem, too.
+  If so, please let the SCons development team know
+  (preferably by filing a bug report
+  or feature request at our project pages at tigris.org)
+  so that we can use your feedback
+  to try to come up with a better way to help you,
+  and others, get the necessary insight into &SCons; behavior
+  to help identify and fix configuration issues.
+
+  </para>
+
+  <section>
+  <title>Why is That Target Being Rebuilt?  the &debug-explain; Option</title>
+
+    <para>
+
+    Let's look at a simple example of
+    a misconfigured build
+    that causes a target to be rebuilt
+    every time &SCons; is run:
+
+    </para>
+
+    <scons_example name="explain1">
+      <file name="SConstruct" printme="1">
+      # Intentionally misspell the output file name in the
+      # command used to create the file:
+      Command('file.out', 'file.in', 'cp $SOURCE file.oout')
+      </file>
+      <file name="file.in">
+      file.in
+      </file>
+    </scons_example>
+
+    <para>
+
+    (Note to Windows users:  The POSIX &cp; command
+    copies the first file named on the command line
+    to the second file.
+    In our example, it copies the &file_in; file
+    to the &file_out; file.)
+
+    </para>
+
+    <para>
+
+    Now if we run &SCons; multiple times on this example,
+    we see that it re-runs the &cp;
+    command every time:
+
+    </para>
+
+    <scons_output example="explain1" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    In this example,
+    the underlying cause is obvious:
+    we've intentionally misspelled the output file name
+    in the &cp; command,
+    so the command doesn't actually
+    build the &file_out; file that we've told &SCons; to expect.
+    But if the problem weren't obvious,
+    it would be helpful
+    to specify the &debug-explain; option
+    on the command line
+    to have &SCons; tell us very specifically
+    why it's decided to rebuild the target:
+
+    </para>
+
+    <scons_output example="explain1" os="posix">
+      <scons_output_command>scons -Q --debug=explain</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    If this had been a more complicated example
+    involving a lot of build output,
+    having &SCons; tell us that
+    it's trying to rebuild the target file
+    because it doesn't exist
+    would be an important clue
+    that something was wrong with
+    the command that we invoked to build it.
+
+    </para>
+
+    <para>
+
+    The &debug-explain; option also comes in handy
+    to help figure out what input file changed.
+    Given a simple configuration that builds
+    a program from three source files,
+    changing one of the source files
+    and rebuilding with the &debug-explain;
+    option shows very specifically
+    why &SCons; rebuilds the files that it does:
+
+    </para>
+
+    <scons_example name="explain2">
+      <file name="SConstruct">
+      Program('prog', ['file1.c', 'file2.c', 'file3.c'])
+      </file>
+      <file name="file1.c">
+      file1.c
+      </file>
+      <file name="file2.c">
+      file2.c
+      </file>
+      <file name="file3.c">
+      file3.c
+      </file>
+    </scons_example>
+
+    <scons_output example="explain2" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command output="    [CHANGE THE CONTENTS OF file2.c]">edit file2.c</scons_output_command>
+      <scons_output_command>scons -Q --debug=explain</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    This becomes even more helpful
+    in identifying when a file is rebuilt
+    due to a change in an implicit dependency,
+    such as an incuded <filename>.h</filename> file.
+    If the <filename>file1.c</filename>
+    and <filename>file3.c</filename> files
+    in our example
+    both included a &hello_h; file,
+    then changing that included file
+    and re-running &SCons; with the &debug-explain; option
+    will pinpoint that it's the change to the included file
+    that starts the chain of rebuilds:
+
+    </para>
+
+    <scons_example name="explain3">
+      <file name="SConstruct">
+      Program('prog', ['file1.c', 'file2.c', 'file3.c'], CPPPATH='.')
+      </file>
+      <file name="file1.c">
+      #include &lt;hello.h&gt;
+      file1.c
+      </file>
+      <file name="file2.c">
+      file2.c
+      </file>
+      <file name="file3.c">
+      #include &lt;hello.h&gt;
+      file3.c
+      </file>
+      <file name="hello.h">
+      #define string    "world"
+      </file>
+    </scons_example>
+
+    <scons_output example="explain3" os="posix">
+      <scons_output_command>scons -Q</scons_output_command>
+      <scons_output_command output="    [CHANGE THE CONTENTS OF hello.h]">edit hello.h</scons_output_command>
+      <scons_output_command>scons -Q --debug=explain</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    (Note that the &debug-explain; option will only tell you
+    why &SCons; decided to rebuild necessary targets.
+    It does not tell you what files it examined
+    when deciding <emphasis>not</emphasis>
+    to rebuild a target file,
+    which is often a more valuable question to answer.)
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>What's in That Construction Environment?  the &Dump; Method</title>
+
+    <para>
+
+    When you create a construction environment,
+    &SCons; populates it
+    with construction variables that are set up
+    for various compilers, linkers and utilities
+    that it finds on your system.
+    Although this is usually helpful and what you want,
+    it might be frustrating if &SCons;
+    doesn't set certain variables that you
+    expect to be set.
+    In situations like this,
+    it's sometimes helpful to use the
+    construction environment &Dump; method
+    to print all or some of
+    the construction variables.
+    Note that the &Dump; method
+    <emphasis>returns</emphasis>
+    the representation of the variables
+    in the environment
+    for you to print (or otherwise manipulate):
+
+    </para>
+
+    <scons_example name="Dump">
+      <file name="SConstruct" printme="1">
+         env = Environment()
+         print env.Dump()
+      </file>
+    </scons_example>
+
+    <para>
+
+    On a POSIX system with gcc installed,
+    this might generate:
+
+    </para>
+
+    <scons_output example="Dump" os="posix" tools="gcc">
+      <scons_output_command>scons</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    On a Windows system with Visual C++
+    the output might look like:
+
+    </para>
+
+    <scons_output example="Dump" os="win32" tools="msvc">
+      <scons_output_command>scons</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The construction environments in these examples have
+    actually been restricted to just gcc and Visual C++,
+    respectively.
+    In a real-life situation,
+    the construction environments will
+    likely contain a great many more variables.
+    Also note that we've massaged the example output above
+    to make the memory address of all objects a constant 0x700000.
+    In reality, you would see a different hexadecimal
+    number for each object.
+
+    </para>
+
+    <para>
+
+    To make it easier to see just what you're
+    interested in,
+    the &Dump; method allows you to
+    specify a specific constrcution variable
+    that you want to disply.
+    For example,
+    it's not unusual to want to verify
+    the external environment used to execute build commands,
+    to make sure that the PATH and other
+    environment variables are set up the way they should be.
+    You can do this as follows:
+
+    </para>
+
+    <scons_example name="Dump_ENV">
+      <file name="SConstruct" printme="1">
+         env = Environment()
+         print env.Dump('ENV')
+      </file>
+    </scons_example>
+
+    <para>
+
+    Which might display the following when executed on a POSIX system:
+
+    </para>
+
+    <scons_output example="Dump_ENV" os="posix">
+      <scons_output_command>scons</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    And the following when executed on a Windows system:
+
+    </para>
+
+    <scons_output example="Dump_ENV" os="win32">
+      <scons_output_command>scons</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <section>
+
+  <title>What Dependencies Does &SCons; Know About?  the &tree; Option</title>
+
+    <para>
+
+    Sometimes the best way to try to figure out what
+    &SCons; is doing is simply to take a look at the
+    dependency graph that it constructs
+    based on your &SConscript; files.
+    The <literal>--tree</literal> option
+    will display all or part of the
+    &SCons; dependency graph in an
+    "ASCII art" graphical format
+    that shows the dependency hierarchy.
+
+    </para>
+
+    <para>
+
+    For example, given the following input &SConstruct; file:
+
+    </para>
+
+    <scons_example name="tree1">
+      <file name="SConstruct" printme="1">
+         env = Environment(CPPPATH = ['.'])
+         env.Program('prog', ['f1.c', 'f2.c', 'f3.c'])
+      </file>
+      <file name="f1.c">
+      #include "inc.h"
+      </file>
+      <file name="f2.c">
+      #include "inc.h"
+      </file>
+      <file name="f3.c">
+      #include "inc.h"
+      </file>
+      <file name="inc.h">
+      inc.h
+      </file>
+    </scons_example>
+
+    <para>
+
+    Running &SCons; with the <literal>--tree=all</literal>
+    option yields:
+
+    </para>
+
+    <scons_output example="tree1">
+      <scons_output_command>scons -Q --tree=all</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The tree will also be printed when the
+    <literal>-n</literal> (no execute) option is used,
+    which allows you to examine the dependency graph
+    for a configuration without actually
+    rebuilding anything in the tree.
+
+    </para>
+
+    <para>
+
+    The <literaL>--tree</literal> option only prints
+    the dependency graph for the specified targets
+    (or the default target(s) if none are specified on the command line).
+    So if you specify a target like <filename>f2.o</filename>
+    on the command line,
+    the <literaL>--tree</literal> option will only
+    print the dependency graph for that file:
+
+    </para>
+
+    <scons_output example="tree1">
+      <scons_output_command>scons -Q --tree=all f2.o</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    This is, of course, useful for
+    restricting the output from a very large
+    build configuration to just a
+    portion in which you're interested.
+    Multiple targets are fine,
+    in which case a tree will be printed
+    for each specified target:
+
+    </para>
+
+    <scons_output example="tree1">
+      <scons_output_command>scons -Q --tree=all f1.o f3.o</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The <literal>status</literal> argument may be used
+    to tell &SCons; to print status information about
+    each file in the dependency graph:
+
+    </para>
+
+    <scons_output example="tree1">
+      <scons_output_command>scons -Q --tree=status</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Note that <literal>--tree=all,status</literal> is equivalent;
+    the <literal>all</literal>
+    is assumed if only <literal>status</literal> is present.
+    As an alternative to <literal>all</literal>,
+    you can specify <literal>--tree=derived</literal>
+    to have &SCons; only print derived targets
+    in the tree output,
+    skipping source files
+    (like <filename>.c</filename> and <filename>.h</filename> files):
+
+    </para>
+
+    <scons_output example="tree1">
+      <scons_output_command>scons -Q --tree=derived</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    You can use the <literal>status</literal>
+    modifier with <literal>derived</literal> as well:
+
+    </para>
+
+    <scons_output example="tree1">
+      <scons_output_command>scons -Q --tree=derived,status</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Note that the order of the <literal>--tree=</literal>
+    arguments doesn't matter;
+    <literal>--tree=status,derived</literal> is
+    completely equivalent.
+
+    </para>
+
+    <para>
+
+    The default behavior of the <literal>--tree</literal> option
+    is to repeat all of the dependencies each time the library dependency
+    (or any other dependency file) is encountered in the tree.
+    If certain target files share other target files,
+    such as two programs that use the same library:
+
+    </para>
+
+    <scons_example name="tree2">
+      <file name="SConstruct" printme="1">
+         env = Environment(CPPPATH = ['.'],
+                           LIBS = ['foo'],
+                           LIBPATH = ['.'])
+         env.Library('foo', ['f1.c', 'f2.c', 'f3.c'])
+         env.Program('prog1.c')
+         env.Program('prog2.c')
+      </file>
+      <file name="prog1.c">
+      #include "inc.h"
+      </file>
+      <file name="prog2.c">
+      #include "inc.h"
+      </file>
+      <file name="f1.c">
+      #include "inc.h"
+      </file>
+      <file name="f2.c">
+      #include "inc.h"
+      </file>
+      <file name="f3.c">
+      #include "inc.h"
+      </file>
+      <file name="inc.h">
+      inc.h
+      </file>
+    </scons_example>
+
+    <para>
+
+    Then there can be a <emphasis>lot</emphasis> of repetition in the
+    <literal>--tree=</literal> output:
+
+    </para>
+
+    <scons_output example="tree2">
+      <scons_output_command>scons -Q --tree=all</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    In a large configuration with many internal libraries
+    and include files,
+    this can very quickly lead to huge output trees.
+    To help make this more manageable,
+    a <literal>prune</literal> modifier may
+    be added to the option list,
+    in which case &SCons;
+    will print the name of a target that has
+    already been visited during the tree-printing
+    in <literal>[square brackets]</literal>
+    as an indication that the dependencies
+    of the target file may be found
+    by looking farther up the tree:
+
+    </para>
+
+    <scons_output example="tree2">
+      <scons_output_command>scons -Q --tree=prune</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Like the <literal>status</literal> keyword,
+    the <literal>prune</literal> argument by itself
+    is equivalent to <literal>--tree=all,prune</literal>.
+
+    </para>
+
+  </section>
+
+  <section>
+
+  <title>How is &SCons; Constructing the Command Lines It Executes?  the &debug-presub; Option</title>
+
+    <para>
+
+    Sometimes it's useful to look at the
+    pre-substitution string
+    that &SCons; uses to generate
+    the command lines it executes.
+    This can be done with the &debug-presub; option:
+
+    </para>
+
+    <scons_example name="presub">
+      <file name="SConstruct">
+         env = Environment(CPPPATH = ['.'])
+         env.Program('prog', 'prog.c')
+      </file>
+      <file name="prog.c">
+      prog.c
+      </file>
+    </scons_example>
+
+    <!--
+
+    Have to capture output here, otherwise the - -debug=presub output
+    shows the Python functions from the sconsdoc.py execution wrapper
+    used to generate this manual, not the underlying command-line strings.
+
+    <scons_output example="presub">
+      <scons_output_command>scons -Q - -debug=presub</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q --debug=presub</userinput>
+      Building prog.o with action:
+        $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCOMCOM $SOURCES
+      cc -o prog.o -c -I. prog.c
+      Building prog with action:
+        $SMART_LINKCOM
+      cc -o prog prog.o
+    </screen>
+
+  </section>
+
+  <section>
+
+  <title>Where is &SCons; Searching for Libraries?  the &debug-findlibs; Option</title>
+
+    <para>
+
+    To get some insight into what library names
+    &SCons; is searching for,
+    and in which directories it is searching,
+    Use the <literal>--debug=findlibs</literal> option.
+    Given the following input &SConstruct; file:
+
+    </para>
+
+    <scons_example name="findlibs">
+      <file name="SConstruct" printme="1">
+        env = Environment(LIBPATH = ['libs1', 'libs2'])
+        env.Program('prog.c', LIBS=['foo', 'bar'])
+      </file>
+      <file name="prog.c">
+      prog.c
+      </file>
+      <file name="libs1/libfoo.a">
+      libs1/libfoo.a
+      </file>
+      <file name="libs2/libbar.a">
+      libs2/libbar.a
+      </file>
+    </scons_example>
+
+    <para>
+
+    And the libraries <filename>libfoo.a</filename>
+    and <filename>libbar.a</filename>
+    in <filename>libs1</filename> and <filename>libs2</filename>,
+    respectively,
+    use of the <literal>--debug=findlibs</literal> option yields:
+
+    </para>
+
+    <scons_output example="findlibs">
+      <scons_output_command>scons -Q --debug=findlibs</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  <!--
+
+  <section>
+
+  <title>What Implicit Dependencies Did the &SCons; Scanner find?  the &debug-includes; Option</title>
+
+    <para>
+
+    XXX explain the - - debug=includes option
+
+    </para>
+
+    <scons_example name="includes">
+      <file name="SConstruct" printme="1">
+        env = Environment(CPPPATH = ['inc1', 'inc2'])
+        env.Program('prog.c')
+      </file>
+      <file name="prog.c">
+      #include "file1.h"
+      #include "file2.h"
+      prog.c
+      </file>
+      <file name="inc1/file1.h">
+      inc1/file1.h
+      </file>
+      <file name="inc2/file2.h">
+      inc2/file2.h
+      </file>
+    </scons_example>
+
+    <scons_output example="includes">
+      <scons_output_command>scons -Q - - debug=includes prog</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  -->
+
+  <section>
+
+  <title>Where is &SCons; Blowing Up?  the &debug-stacktrace; Option</title>
+
+    <para>
+
+    In general, &SCons; tries to keep its error
+    messages short and informative.
+    That means we usually try to avoid showing
+    the stack traces that are familiar
+    to experienced Python programmers,
+    since they usually contain much more
+    information than is useful to most people.
+
+    </para>
+
+    <para>
+
+    For example, the following &SConstruct file:
+
+    </para>
+
+    <scons_example name="stacktrace">
+      <file name="SConstruct" printme="1">
+         Program('prog.c')
+      </file>
+    </scons_example>
+
+    <para>
+
+    Generates the following error if the
+    <filename>prog.c</filename> file
+    does not exist:
+
+    </para>
+
+    <scons_output example="stacktrace">
+      <scons_output_command>scons -Q</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    In this case,
+    the error is pretty obvious.
+    But if it weren't,
+    and you wanted to try to get more information
+    about the error,
+    the &debug-stacktrace; option
+    would show you exactly where in the &SCons; source code
+    the problem occurs:
+
+    </para>
+
+    <scons_output example="stacktrace">
+      <scons_output_command>scons -Q --debug=stacktrace</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    Of course, if you do need to dive into the &SCons; source code,
+    we'd like to know if, or how,
+    the error messages or troubleshooting options
+    could have been improved to avoid that.
+    Not everyone has the necessary time or
+    Python skill to dive into the source code,
+    and we'd like to improve &SCons;
+    for those people as well...
+
+    </para>
+
+  </section>
+
+  <section>
+
+  <title>How is &SCons; Making Its Decisions?  the &taskmastertrace; Option</title>
+
+    <para>
+
+    The internal &SCons; subsystem that handles walking
+    the dependency graph
+    and controls the decision-making about what to rebuild
+    is the <literal>Taskmaster</literal>.
+    &SCons; supports a <literal>--taskmastertrace</literal>
+    option that tells the Taskmaster to print
+    information about the children (dependencies)
+    of the various Nodes on its walk down the graph,
+    which specific dependent Nodes are being evaluated,
+    and in what order.
+
+    </para>
+
+    <para>
+
+    The <literal>--taskmastertrace</literal> option
+    takes as an argument the name of a file in
+    which to put the trace output,
+    with <filename>-</filename> (a single hyphen)
+    indicating that the trace messages
+    should be printed to the standard output:
+
+    </para>
+
+    <scons_example name="taskmastertrace">
+      <file name="SConstruct" printme="1">
+      env = Environment(CPPPATH = ['.'])
+      env.Program('prog.c')
+      </file>
+      <file name="prog.c">
+      #include "inc.h"
+      prog.c
+      </file>
+      <file name="inc.h">
+      #define   STRING  "one"
+      </file>
+    </scons_example>
+
+    <scons_output example="taskmastertrace" os="posix">
+      <scons_output_command>scons -Q --taskmastertrace=- prog</scons_output_command>
+    </scons_output>
+
+    <para>
+
+    The <literal>--taskmastertrace</literal> option
+    doesn't provide information about the actual
+    calculations involved in deciding if a file is up-to-date,
+    but it does show all of the dependencies
+    it knows about for each Node,
+    and the order in which those dependencies are evaluated.
+    This can be useful as an alternate way to determine
+    whether or not your &SCons; configuration,
+    or the implicit dependency scan,
+    has actually identified all the correct dependencies
+    you want it to.
+
+    </para>
+
+  </section>
+
+  <!--
+
+  <section>
+
+  <title>Where Are My Build Bottlenecks?  the &profile; Option</title>
+
+    <para>
+
+    XXX explain the - - profile= option
+
+    </para>
+
+  </section>
+
+  -->
+
+  <!--
+
+  <section>
+  <title>Troubleshooting Shared Caching:  the &cache-debug; Option</title>
+
+    <para>
+
+    XXX describe the - - cache-debug option
+    XXX maybe point to the caching.in chapter?
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/troubleshoot.xml b/doc/user/troubleshoot.xml
new file mode 100644
index 0000000..6bd53f9
--- /dev/null
+++ b/doc/user/troubleshoot.xml
@@ -0,0 +1,1313 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+  <para>
+
+  The experience of configuring any
+  software build tool to build a large code base
+  usually, at some point,
+  involves trying to figure out why
+  the tool is behaving a certain way,
+  and how to get it to behave the way you want.
+  &SCons; is no different.
+  This appendix contains a number of
+  different ways in which you can
+  get some additional insight into &SCons;' behavior.
+
+  </para>
+
+  <para>
+
+  Note that we're always interested in trying to
+  improve how you can troubleshoot configuration problems.
+  If you run into a problem that has
+  you scratching your head,
+  and which there just doesn't seem to be a good way to debug,
+  odds are pretty good that someone else will run into
+  the same problem, too.
+  If so, please let the SCons development team know
+  (preferably by filing a bug report
+  or feature request at our project pages at tigris.org)
+  so that we can use your feedback
+  to try to come up with a better way to help you,
+  and others, get the necessary insight into &SCons; behavior
+  to help identify and fix configuration issues.
+
+  </para>
+
+  <section>
+  <title>Why is That Target Being Rebuilt?  the &debug-explain; Option</title>
+
+    <para>
+
+    Let's look at a simple example of
+    a misconfigured build
+    that causes a target to be rebuilt
+    every time &SCons; is run:
+
+    </para>
+
+    <programlisting>
+      # Intentionally misspell the output file name in the
+      # command used to create the file:
+      Command('file.out', 'file.in', 'cp $SOURCE file.oout')
+    </programlisting>
+
+    <para>
+
+    (Note to Windows users:  The POSIX &cp; command
+    copies the first file named on the command line
+    to the second file.
+    In our example, it copies the &file_in; file
+    to the &file_out; file.)
+
+    </para>
+
+    <para>
+
+    Now if we run &SCons; multiple times on this example,
+    we see that it re-runs the &cp;
+    command every time:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cp file.in file.oout
+      % <userinput>scons -Q</userinput>
+      cp file.in file.oout
+      % <userinput>scons -Q</userinput>
+      cp file.in file.oout
+    </screen>
+
+    <para>
+
+    In this example,
+    the underlying cause is obvious:
+    we've intentionally misspelled the output file name
+    in the &cp; command,
+    so the command doesn't actually
+    build the &file_out; file that we've told &SCons; to expect.
+    But if the problem weren't obvious,
+    it would be helpful
+    to specify the &debug-explain; option
+    on the command line
+    to have &SCons; tell us very specifically
+    why it's decided to rebuild the target:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q --debug=explain</userinput>
+      scons: building `file.out' because it doesn't exist
+      cp file.in file.oout
+    </screen>
+
+    <para>
+
+    If this had been a more complicated example
+    involving a lot of build output,
+    having &SCons; tell us that
+    it's trying to rebuild the target file
+    because it doesn't exist
+    would be an important clue
+    that something was wrong with
+    the command that we invoked to build it.
+
+    </para>
+
+    <para>
+
+    The &debug-explain; option also comes in handy
+    to help figure out what input file changed.
+    Given a simple configuration that builds
+    a program from three source files,
+    changing one of the source files
+    and rebuilding with the &debug-explain;
+    option shows very specifically
+    why &SCons; rebuilds the files that it does:
+
+    </para>
+
+    
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o file1.o -c file1.c
+      cc -o file2.o -c file2.c
+      cc -o file3.o -c file3.c
+      cc -o prog file1.o file2.o file3.o
+      % <userinput>edit file2.c</userinput>
+          [CHANGE THE CONTENTS OF file2.c]
+      % <userinput>scons -Q --debug=explain</userinput>
+      scons: rebuilding `file2.o' because `file2.c' changed
+      cc -o file2.o -c file2.c
+      scons: rebuilding `prog' because `file2.o' changed
+      cc -o prog file1.o file2.o file3.o
+    </screen>
+
+    <para>
+
+    This becomes even more helpful
+    in identifying when a file is rebuilt
+    due to a change in an implicit dependency,
+    such as an incuded <filename>.h</filename> file.
+    If the <filename>file1.c</filename>
+    and <filename>file3.c</filename> files
+    in our example
+    both included a &hello_h; file,
+    then changing that included file
+    and re-running &SCons; with the &debug-explain; option
+    will pinpoint that it's the change to the included file
+    that starts the chain of rebuilds:
+
+    </para>
+
+    
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      cc -o file1.o -c -I. file1.c
+      cc -o file2.o -c -I. file2.c
+      cc -o file3.o -c -I. file3.c
+      cc -o prog file1.o file2.o file3.o
+      % <userinput>edit hello.h</userinput>
+          [CHANGE THE CONTENTS OF hello.h]
+      % <userinput>scons -Q --debug=explain</userinput>
+      scons: rebuilding `file1.o' because `hello.h' changed
+      cc -o file1.o -c -I. file1.c
+      scons: rebuilding `file3.o' because `hello.h' changed
+      cc -o file3.o -c -I. file3.c
+      scons: rebuilding `prog' because:
+                 `file1.o' changed
+                 `file3.o' changed
+      cc -o prog file1.o file2.o file3.o
+    </screen>
+
+    <para>
+
+    (Note that the &debug-explain; option will only tell you
+    why &SCons; decided to rebuild necessary targets.
+    It does not tell you what files it examined
+    when deciding <emphasis>not</emphasis>
+    to rebuild a target file,
+    which is often a more valuable question to answer.)
+
+    </para>
+
+  </section>
+
+  <section>
+  <title>What's in That Construction Environment?  the &Dump; Method</title>
+
+    <para>
+
+    When you create a construction environment,
+    &SCons; populates it
+    with construction variables that are set up
+    for various compilers, linkers and utilities
+    that it finds on your system.
+    Although this is usually helpful and what you want,
+    it might be frustrating if &SCons;
+    doesn't set certain variables that you
+    expect to be set.
+    In situations like this,
+    it's sometimes helpful to use the
+    construction environment &Dump; method
+    to print all or some of
+    the construction variables.
+    Note that the &Dump; method
+    <emphasis>returns</emphasis>
+    the representation of the variables
+    in the environment
+    for you to print (or otherwise manipulate):
+
+    </para>
+
+    <programlisting>
+         env = Environment()
+         print env.Dump()
+    </programlisting>
+
+    <para>
+
+    On a POSIX system with gcc installed,
+    this might generate:
+
+    </para>
+
+    <screen>
+      % <userinput>scons</userinput>
+      scons: Reading SConscript files ...
+      { 'BUILDERS': {'_InternalInstall': &lt;function InstallBuilderWrapper at 0x700000&gt;, '_InternalInstallAs': &lt;function InstallAsBuilderWrapper at 0x700000&gt;},
+        'CONFIGUREDIR': '#/.sconf_temp',
+        'CONFIGURELOG': '#/config.log',
+        'CPPSUFFIXES': [ '.c',
+                         '.C',
+                         '.cxx',
+                         '.cpp',
+                         '.c++',
+                         '.cc',
+                         '.h',
+                         '.H',
+                         '.hxx',
+                         '.hpp',
+                         '.hh',
+                         '.F',
+                         '.fpp',
+                         '.FPP',
+                         '.m',
+                         '.mm',
+                         '.S',
+                         '.spp',
+                         '.SPP'],
+        'DSUFFIXES': ['.d'],
+        'Dir': &lt;SCons.Defaults.Variable_Method_Caller instance at 0x700000&gt;,
+        'Dirs': &lt;SCons.Defaults.Variable_Method_Caller instance at 0x700000&gt;,
+        'ENV': {'PATH': '/usr/local/bin:/opt/bin:/bin:/usr/bin'},
+        'ESCAPE': &lt;function escape at 0x700000&gt;,
+        'File': &lt;SCons.Defaults.Variable_Method_Caller instance at 0x700000&gt;,
+        'HOST_ARCH': None,
+        'HOST_OS': None,
+        'IDLSUFFIXES': ['.idl', '.IDL'],
+        'INSTALL': &lt;function copyFunc at 0x700000&gt;,
+        'LIBPREFIX': 'lib',
+        'LIBPREFIXES': ['$LIBPREFIX'],
+        'LIBSUFFIX': '.a',
+        'LIBSUFFIXES': ['$LIBSUFFIX', '$SHLIBSUFFIX'],
+        'MAXLINELENGTH': 128072,
+        'OBJPREFIX': '',
+        'OBJSUFFIX': '.o',
+        'PLATFORM': 'posix',
+        'PROGPREFIX': '',
+        'PROGSUFFIX': '',
+        'PSPAWN': &lt;function piped_env_spawn at 0x700000&gt;,
+        'RDirs': &lt;SCons.Defaults.Variable_Method_Caller instance at 0x700000&gt;,
+        'SCANNERS': [],
+        'SHELL': 'sh',
+        'SHLIBPREFIX': '$LIBPREFIX',
+        'SHLIBSUFFIX': '.so',
+        'SHOBJPREFIX': '$OBJPREFIX',
+        'SHOBJSUFFIX': '$OBJSUFFIX',
+        'SPAWN': &lt;function spawnvpe_spawn at 0x700000&gt;,
+        'TARGET_ARCH': None,
+        'TARGET_OS': None,
+        'TEMPFILE': &lt;class SCons.Platform.TempFileMunge at 0x700000&gt;,
+        'TEMPFILEPREFIX': '@',
+        'TOOLS': ['install', 'install'],
+        '_CPPDEFFLAGS': '${_defines(CPPDEFPREFIX, CPPDEFINES, CPPDEFSUFFIX, __env__)}',
+        '_CPPINCFLAGS': '$( ${_concat(INCPREFIX, CPPPATH, INCSUFFIX, __env__, RDirs, TARGET, SOURCE)} $)',
+        '_LIBDIRFLAGS': '$( ${_concat(LIBDIRPREFIX, LIBPATH, LIBDIRSUFFIX, __env__, RDirs, TARGET, SOURCE)} $)',
+        '_LIBFLAGS': '${_concat(LIBLINKPREFIX, LIBS, LIBLINKSUFFIX, __env__)}',
+        '__RPATH': '$_RPATH',
+        '_concat': &lt;function _concat at 0x700000&gt;,
+        '_defines': &lt;function _defines at 0x700000&gt;,
+        '_stripixes': &lt;function _stripixes at 0x700000&gt;}
+      scons: done reading SConscript files.
+      scons: Building targets ...
+      scons: `.' is up to date.
+      scons: done building targets.
+    </screen>
+
+    <para>
+
+    On a Windows system with Visual C++
+    the output might look like:
+
+    </para>
+
+    <screen>
+      C:\><userinput>scons</userinput>
+      scons: Reading SConscript files ...
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      { 'BUILDERS': {'_InternalInstall': &lt;function InstallBuilderWrapper at 0x700000&gt;, 'Object': &lt;SCons.Builder.CompositeBuilder instance at 0x700000&gt;, 'PCH': &lt;SCons.Builder.BuilderBase instance at 0x700000&gt;, 'RES': &lt;SCons.Builder.BuilderBase instance at 0x700000&gt;, 'SharedObject': &lt;SCons.Builder.CompositeBuilder instance at 0x700000&gt;, 'StaticObject': &lt;SCons.Builder.CompositeBuilder instance at 0x700000&gt;, '_InternalInstallAs': &lt;function InstallAsBuilderWrapper at 0x700000&gt;},
+        'CC': 'cl',
+        'CCCOM': &lt;SCons.Action.FunctionAction instance at 0x700000&gt;,
+        'CCFLAGS': ['/nologo'],
+        'CCPCHFLAGS': ['${(PCH and "/Yu%s /Fp%s"%(PCHSTOP or "",File(PCH))) or ""}'],
+        'CCPDBFLAGS': ['${(PDB and "/Z7") or ""}'],
+        'CFILESUFFIX': '.c',
+        'CFLAGS': [],
+        'CONFIGUREDIR': '#/.sconf_temp',
+        'CONFIGURELOG': '#/config.log',
+        'CPPDEFPREFIX': '/D',
+        'CPPDEFSUFFIX': '',
+        'CPPSUFFIXES': [ '.c',
+                         '.C',
+                         '.cxx',
+                         '.cpp',
+                         '.c++',
+                         '.cc',
+                         '.h',
+                         '.H',
+                         '.hxx',
+                         '.hpp',
+                         '.hh',
+                         '.F',
+                         '.fpp',
+                         '.FPP',
+                         '.m',
+                         '.mm',
+                         '.S',
+                         '.spp',
+                         '.SPP'],
+        'CXX': '$CC',
+        'CXXCOM': '$CXX $_MSVC_OUTPUT_FLAG /c $CHANGED_SOURCES $CXXFLAGS $CCFLAGS $_CCCOMCOM',
+        'CXXFILESUFFIX': '.cc',
+        'CXXFLAGS': ['$(', '/TP', '$)'],
+        'DSUFFIXES': ['.d'],
+        'Dir': &lt;SCons.Defaults.Variable_Method_Caller instance at 0x700000&gt;,
+        'Dirs': &lt;SCons.Defaults.Variable_Method_Caller instance at 0x700000&gt;,
+        'ENV': { 'PATH': 'C:/WINDOWS\\System32',
+                 'PATHEXT': '.COM;.EXE;.BAT;.CMD',
+                 'SystemRoot': 'C:/WINDOWS'},
+        'ESCAPE': &lt;function escape at 0x700000&gt;,
+        'File': &lt;SCons.Defaults.Variable_Method_Caller instance at 0x700000&gt;,
+        'HOST_ARCH': '',
+        'HOST_OS': 'win32',
+        'IDLSUFFIXES': ['.idl', '.IDL'],
+        'INCPREFIX': '/I',
+        'INCSUFFIX': '',
+        'INSTALL': &lt;function copyFunc at 0x700000&gt;,
+        'LIBPREFIX': '',
+        'LIBPREFIXES': ['$LIBPREFIX'],
+        'LIBSUFFIX': '.lib',
+        'LIBSUFFIXES': ['$LIBSUFFIX'],
+        'MAXLINELENGTH': 2048,
+        'MSVC_SETUP_RUN': True,
+        'OBJPREFIX': '',
+        'OBJSUFFIX': '.obj',
+        'PCHCOM': '$CXX /Fo${TARGETS[1]} $CXXFLAGS $CCFLAGS $CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS /c $SOURCES /Yc$PCHSTOP /Fp${TARGETS[0]} $CCPDBFLAGS $PCHPDBFLAGS',
+        'PCHPDBFLAGS': ['${(PDB and "/Yd") or ""}'],
+        'PLATFORM': 'win32',
+        'PROGPREFIX': '',
+        'PROGSUFFIX': '.exe',
+        'PSPAWN': &lt;function piped_spawn at 0x700000&gt;,
+        'RC': 'rc',
+        'RCCOM': &lt;SCons.Action.FunctionAction instance at 0x700000&gt;,
+        'RCFLAGS': [],
+        'RCSUFFIXES': ['.rc', '.rc2'],
+        'RDirs': &lt;SCons.Defaults.Variable_Method_Caller instance at 0x700000&gt;,
+        'SCANNERS': [],
+        'SHCC': '$CC',
+        'SHCCCOM': &lt;SCons.Action.FunctionAction instance at 0x700000&gt;,
+        'SHCCFLAGS': ['$CCFLAGS'],
+        'SHCFLAGS': ['$CFLAGS'],
+        'SHCXX': '$CXX',
+        'SHCXXCOM': '$SHCXX $_MSVC_OUTPUT_FLAG /c $CHANGED_SOURCES $SHCXXFLAGS $SHCCFLAGS $_CCCOMCOM',
+        'SHCXXFLAGS': ['$CXXFLAGS'],
+        'SHELL': None,
+        'SHLIBPREFIX': '',
+        'SHLIBSUFFIX': '.dll',
+        'SHOBJPREFIX': '$OBJPREFIX',
+        'SHOBJSUFFIX': '$OBJSUFFIX',
+        'SPAWN': &lt;function spawn at 0x700000&gt;,
+        'STATIC_AND_SHARED_OBJECTS_ARE_THE_SAME': 1,
+        'TARGET_ARCH': '',
+        'TARGET_OS': 'win32',
+        'TEMPFILE': &lt;class SCons.Platform.TempFileMunge at 0x700000&gt;,
+        'TEMPFILEPREFIX': '@',
+        'TOOLS': ['msvc', 'install', 'install'],
+        '_CCCOMCOM': '$CPPFLAGS $_CPPDEFFLAGS $_CPPINCFLAGS $CCPCHFLAGS $CCPDBFLAGS',
+        '_CPPDEFFLAGS': '${_defines(CPPDEFPREFIX, CPPDEFINES, CPPDEFSUFFIX, __env__)}',
+        '_CPPINCFLAGS': '$( ${_concat(INCPREFIX, CPPPATH, INCSUFFIX, __env__, RDirs, TARGET, SOURCE)} $)',
+        '_LIBDIRFLAGS': '$( ${_concat(LIBDIRPREFIX, LIBPATH, LIBDIRSUFFIX, __env__, RDirs, TARGET, SOURCE)} $)',
+        '_LIBFLAGS': '${_concat(LIBLINKPREFIX, LIBS, LIBLINKSUFFIX, __env__)}',
+        '_MSVC_OUTPUT_FLAG': &lt;function msvc_output_flag at 0x700000&gt;,
+        '_concat': &lt;function _concat at 0x700000&gt;,
+        '_defines': &lt;function _defines at 0x700000&gt;,
+        '_stripixes': &lt;function _stripixes at 0x700000&gt;}
+      scons: done reading SConscript files.
+      scons: Building targets ...
+      scons: `.' is up to date.
+      scons: done building targets.
+    </screen>
+
+    <para>
+
+    The construction environments in these examples have
+    actually been restricted to just gcc and Visual C++,
+    respectively.
+    In a real-life situation,
+    the construction environments will
+    likely contain a great many more variables.
+    Also note that we've massaged the example output above
+    to make the memory address of all objects a constant 0x700000.
+    In reality, you would see a different hexadecimal
+    number for each object.
+
+    </para>
+
+    <para>
+
+    To make it easier to see just what you're
+    interested in,
+    the &Dump; method allows you to
+    specify a specific constrcution variable
+    that you want to disply.
+    For example,
+    it's not unusual to want to verify
+    the external environment used to execute build commands,
+    to make sure that the PATH and other
+    environment variables are set up the way they should be.
+    You can do this as follows:
+
+    </para>
+
+    <programlisting>
+         env = Environment()
+         print env.Dump('ENV')
+    </programlisting>
+
+    <para>
+
+    Which might display the following when executed on a POSIX system:
+
+    </para>
+
+    <screen>
+      % <userinput>scons</userinput>
+      scons: Reading SConscript files ...
+      {'PATH': '/usr/local/bin:/opt/bin:/bin:/usr/bin'}
+      scons: done reading SConscript files.
+      scons: Building targets ...
+      scons: `.' is up to date.
+      scons: done building targets.
+    </screen>
+
+    <para>
+
+    And the following when executed on a Windows system:
+
+    </para>
+
+    <screen>
+      C:\><userinput>scons</userinput>
+      scons: Reading SConscript files ...
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No installed VCs
+      File "&lt;stdin&gt;", line 67, in __call__
+      
+      scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+      File "&lt;stdin&gt;", line 67, in __call__
+      { 'PATH': 'C:/WINDOWS\\System32',
+        'PATHEXT': '.COM;.EXE;.BAT;.CMD',
+        'SystemRoot': 'C:/WINDOWS'}
+      scons: done reading SConscript files.
+      scons: Building targets ...
+      scons: `.' is up to date.
+      scons: done building targets.
+    </screen>
+
+  </section>
+
+  <section>
+
+  <title>What Dependencies Does &SCons; Know About?  the &tree; Option</title>
+
+    <para>
+
+    Sometimes the best way to try to figure out what
+    &SCons; is doing is simply to take a look at the
+    dependency graph that it constructs
+    based on your &SConscript; files.
+    The <literal>--tree</literal> option
+    will display all or part of the
+    &SCons; dependency graph in an
+    "ASCII art" graphical format
+    that shows the dependency hierarchy.
+
+    </para>
+
+    <para>
+
+    For example, given the following input &SConstruct; file:
+
+    </para>
+
+    <programlisting>
+         env = Environment(CPPPATH = ['.'])
+         env.Program('prog', ['f1.c', 'f2.c', 'f3.c'])
+    </programlisting>
+
+    <para>
+
+    Running &SCons; with the <literal>--tree=all</literal>
+    option yields:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q --tree=all</userinput>
+      cc -o f1.o -c -I. f1.c
+      cc -o f2.o -c -I. f2.c
+      cc -o f3.o -c -I. f3.c
+      cc -o prog f1.o f2.o f3.o
+      +-.
+        +-SConstruct
+        +-f1.c
+        +-f1.o
+        | +-f1.c
+        | +-inc.h
+        +-f2.c
+        +-f2.o
+        | +-f2.c
+        | +-inc.h
+        +-f3.c
+        +-f3.o
+        | +-f3.c
+        | +-inc.h
+        +-inc.h
+        +-prog
+          +-f1.o
+          | +-f1.c
+          | +-inc.h
+          +-f2.o
+          | +-f2.c
+          | +-inc.h
+          +-f3.o
+            +-f3.c
+            +-inc.h
+    </screen>
+
+    <para>
+
+    The tree will also be printed when the
+    <literal>-n</literal> (no execute) option is used,
+    which allows you to examine the dependency graph
+    for a configuration without actually
+    rebuilding anything in the tree.
+
+    </para>
+
+    <para>
+
+    The <literal>--tree</literal> option only prints
+    the dependency graph for the specified targets
+    (or the default target(s) if none are specified on the command line).
+    So if you specify a target like <filename>f2.o</filename>
+    on the command line,
+    the <literal>--tree</literal> option will only
+    print the dependency graph for that file:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q --tree=all f2.o</userinput>
+      cc -o f2.o -c -I. f2.c
+      +-f2.o
+        +-f2.c
+        +-inc.h
+    </screen>
+
+    <para>
+
+    This is, of course, useful for
+    restricting the output from a very large
+    build configuration to just a
+    portion in which you're interested.
+    Multiple targets are fine,
+    in which case a tree will be printed
+    for each specified target:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q --tree=all f1.o f3.o</userinput>
+      cc -o f1.o -c -I. f1.c
+      +-f1.o
+        +-f1.c
+        +-inc.h
+      cc -o f3.o -c -I. f3.c
+      +-f3.o
+        +-f3.c
+        +-inc.h
+    </screen>
+
+    <para>
+
+    The <literal>status</literal> argument may be used
+    to tell &SCons; to print status information about
+    each file in the dependency graph:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q --tree=status</userinput>
+      cc -o f1.o -c -I. f1.c
+      cc -o f2.o -c -I. f2.c
+      cc -o f3.o -c -I. f3.c
+      cc -o prog f1.o f2.o f3.o
+       E         = exists
+        R        = exists in repository only
+         b       = implicit builder
+         B       = explicit builder
+          S      = side effect
+           P     = precious
+            A    = always build
+             C   = current
+              N  = no clean
+               H = no cache
+      
+      [E b      ]+-.
+      [E     C  ]  +-SConstruct
+      [E     C  ]  +-f1.c
+      [E B   C  ]  +-f1.o
+      [E     C  ]  | +-f1.c
+      [E     C  ]  | +-inc.h
+      [E     C  ]  +-f2.c
+      [E B   C  ]  +-f2.o
+      [E     C  ]  | +-f2.c
+      [E     C  ]  | +-inc.h
+      [E     C  ]  +-f3.c
+      [E B   C  ]  +-f3.o
+      [E     C  ]  | +-f3.c
+      [E     C  ]  | +-inc.h
+      [E     C  ]  +-inc.h
+      [E B   C  ]  +-prog
+      [E B   C  ]    +-f1.o
+      [E     C  ]    | +-f1.c
+      [E     C  ]    | +-inc.h
+      [E B   C  ]    +-f2.o
+      [E     C  ]    | +-f2.c
+      [E     C  ]    | +-inc.h
+      [E B   C  ]    +-f3.o
+      [E     C  ]      +-f3.c
+      [E     C  ]      +-inc.h
+    </screen>
+
+    <para>
+
+    Note that <literal>--tree=all,status</literal> is equivalent;
+    the <literal>all</literal>
+    is assumed if only <literal>status</literal> is present.
+    As an alternative to <literal>all</literal>,
+    you can specify <literal>--tree=derived</literal>
+    to have &SCons; only print derived targets
+    in the tree output,
+    skipping source files
+    (like <filename>.c</filename> and <filename>.h</filename> files):
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q --tree=derived</userinput>
+      cc -o f1.o -c -I. f1.c
+      cc -o f2.o -c -I. f2.c
+      cc -o f3.o -c -I. f3.c
+      cc -o prog f1.o f2.o f3.o
+      +-.
+        +-f1.o
+        +-f2.o
+        +-f3.o
+        +-prog
+          +-f1.o
+          +-f2.o
+          +-f3.o
+    </screen>
+
+    <para>
+
+    You can use the <literal>status</literal>
+    modifier with <literal>derived</literal> as well:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q --tree=derived,status</userinput>
+      cc -o f1.o -c -I. f1.c
+      cc -o f2.o -c -I. f2.c
+      cc -o f3.o -c -I. f3.c
+      cc -o prog f1.o f2.o f3.o
+       E         = exists
+        R        = exists in repository only
+         b       = implicit builder
+         B       = explicit builder
+          S      = side effect
+           P     = precious
+            A    = always build
+             C   = current
+              N  = no clean
+               H = no cache
+      
+      [E b      ]+-.
+      [E B   C  ]  +-f1.o
+      [E B   C  ]  +-f2.o
+      [E B   C  ]  +-f3.o
+      [E B   C  ]  +-prog
+      [E B   C  ]    +-f1.o
+      [E B   C  ]    +-f2.o
+      [E B   C  ]    +-f3.o
+    </screen>
+
+    <para>
+
+    Note that the order of the <literal>--tree=</literal>
+    arguments doesn't matter;
+    <literal>--tree=status,derived</literal> is
+    completely equivalent.
+
+    </para>
+
+    <para>
+
+    The default behavior of the <literal>--tree</literal> option
+    is to repeat all of the dependencies each time the library dependency
+    (or any other dependency file) is encountered in the tree.
+    If certain target files share other target files,
+    such as two programs that use the same library:
+
+    </para>
+
+    <programlisting>
+         env = Environment(CPPPATH = ['.'],
+                           LIBS = ['foo'],
+                           LIBPATH = ['.'])
+         env.Library('foo', ['f1.c', 'f2.c', 'f3.c'])
+         env.Program('prog1.c')
+         env.Program('prog2.c')
+    </programlisting>
+
+    <para>
+
+    Then there can be a <emphasis>lot</emphasis> of repetition in the
+    <literal>--tree=</literal> output:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q --tree=all</userinput>
+      cc -o f1.o -c -I. f1.c
+      cc -o f2.o -c -I. f2.c
+      cc -o f3.o -c -I. f3.c
+      ar rc libfoo.a f1.o f2.o f3.o
+      ranlib libfoo.a
+      cc -o prog1.o -c -I. prog1.c
+      cc -o prog1 prog1.o -L. -lfoo
+      cc -o prog2.o -c -I. prog2.c
+      cc -o prog2 prog2.o -L. -lfoo
+      +-.
+        +-SConstruct
+        +-f1.c
+        +-f1.o
+        | +-f1.c
+        | +-inc.h
+        +-f2.c
+        +-f2.o
+        | +-f2.c
+        | +-inc.h
+        +-f3.c
+        +-f3.o
+        | +-f3.c
+        | +-inc.h
+        +-inc.h
+        +-libfoo.a
+        | +-f1.o
+        | | +-f1.c
+        | | +-inc.h
+        | +-f2.o
+        | | +-f2.c
+        | | +-inc.h
+        | +-f3.o
+        |   +-f3.c
+        |   +-inc.h
+        +-prog1
+        | +-prog1.o
+        | | +-prog1.c
+        | | +-inc.h
+        | +-libfoo.a
+        |   +-f1.o
+        |   | +-f1.c
+        |   | +-inc.h
+        |   +-f2.o
+        |   | +-f2.c
+        |   | +-inc.h
+        |   +-f3.o
+        |     +-f3.c
+        |     +-inc.h
+        +-prog1.c
+        +-prog1.o
+        | +-prog1.c
+        | +-inc.h
+        +-prog2
+        | +-prog2.o
+        | | +-prog2.c
+        | | +-inc.h
+        | +-libfoo.a
+        |   +-f1.o
+        |   | +-f1.c
+        |   | +-inc.h
+        |   +-f2.o
+        |   | +-f2.c
+        |   | +-inc.h
+        |   +-f3.o
+        |     +-f3.c
+        |     +-inc.h
+        +-prog2.c
+        +-prog2.o
+          +-prog2.c
+          +-inc.h
+    </screen>
+
+    <para>
+
+    In a large configuration with many internal libraries
+    and include files,
+    this can very quickly lead to huge output trees.
+    To help make this more manageable,
+    a <literal>prune</literal> modifier may
+    be added to the option list,
+    in which case &SCons;
+    will print the name of a target that has
+    already been visited during the tree-printing
+    in <literal>[square brackets]</literal>
+    as an indication that the dependencies
+    of the target file may be found
+    by looking farther up the tree:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q --tree=prune</userinput>
+      cc -o f1.o -c -I. f1.c
+      cc -o f2.o -c -I. f2.c
+      cc -o f3.o -c -I. f3.c
+      ar rc libfoo.a f1.o f2.o f3.o
+      ranlib libfoo.a
+      cc -o prog1.o -c -I. prog1.c
+      cc -o prog1 prog1.o -L. -lfoo
+      cc -o prog2.o -c -I. prog2.c
+      cc -o prog2 prog2.o -L. -lfoo
+      +-.
+        +-SConstruct
+        +-f1.c
+        +-f1.o
+        | +-f1.c
+        | +-inc.h
+        +-f2.c
+        +-f2.o
+        | +-f2.c
+        | +-inc.h
+        +-f3.c
+        +-f3.o
+        | +-f3.c
+        | +-inc.h
+        +-inc.h
+        +-libfoo.a
+        | +-[f1.o]
+        | +-[f2.o]
+        | +-[f3.o]
+        +-prog1
+        | +-prog1.o
+        | | +-prog1.c
+        | | +-inc.h
+        | +-[libfoo.a]
+        +-prog1.c
+        +-[prog1.o]
+        +-prog2
+        | +-prog2.o
+        | | +-prog2.c
+        | | +-inc.h
+        | +-[libfoo.a]
+        +-prog2.c
+        +-[prog2.o]
+    </screen>
+
+    <para>
+
+    Like the <literal>status</literal> keyword,
+    the <literal>prune</literal> argument by itself
+    is equivalent to <literal>--tree=all,prune</literal>.
+
+    </para>
+
+  </section>
+
+  <section>
+
+  <title>How is &SCons; Constructing the Command Lines It Executes?  the &debug-presub; Option</title>
+
+    <para>
+
+    Sometimes it's useful to look at the
+    pre-substitution string
+    that &SCons; uses to generate
+    the command lines it executes.
+    This can be done with the &debug-presub; option:
+
+    </para>
+
+    
+
+    <!--
+
+    Have to capture output here, otherwise the - -debug=presub output
+    shows the Python functions from the sconsdoc.py execution wrapper
+    used to generate this manual, not the underlying command-line strings.
+
+    <scons_output example="presub">
+      <scons_output_command>scons -Q - -debug=presub</scons_output_command>
+    </scons_output>
+
+    -->
+
+    <screen>
+      % <userinput>scons -Q --debug=presub</userinput>
+      Building prog.o with action:
+        $CC -o $TARGET -c $CFLAGS $CCFLAGS $_CCOMCOM $SOURCES
+      cc -o prog.o -c -I. prog.c
+      Building prog with action:
+        $SMART_LINKCOM
+      cc -o prog prog.o
+    </screen>
+
+  </section>
+
+  <section>
+
+  <title>Where is &SCons; Searching for Libraries?  the &debug-findlibs; Option</title>
+
+    <para>
+
+    To get some insight into what library names
+    &SCons; is searching for,
+    and in which directories it is searching,
+    Use the <literal>--debug=findlibs</literal> option.
+    Given the following input &SConstruct; file:
+
+    </para>
+
+    <programlisting>
+        env = Environment(LIBPATH = ['libs1', 'libs2'])
+        env.Program('prog.c', LIBS=['foo', 'bar'])
+    </programlisting>
+
+    <para>
+
+    And the libraries <filename>libfoo.a</filename>
+    and <filename>libbar.a</filename>
+    in <filename>libs1</filename> and <filename>libs2</filename>,
+    respectively,
+    use of the <literal>--debug=findlibs</literal> option yields:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q --debug=findlibs</userinput>
+        findlibs: looking for 'libfoo.a' in 'libs1' ...
+        findlibs: ... FOUND 'libfoo.a' in 'libs1'
+        findlibs: looking for 'libfoo.so' in 'libs1' ...
+        findlibs: looking for 'libfoo.so' in 'libs2' ...
+        findlibs: looking for 'libbar.a' in 'libs1' ...
+        findlibs: looking for 'libbar.a' in 'libs2' ...
+        findlibs: ... FOUND 'libbar.a' in 'libs2'
+        findlibs: looking for 'libbar.so' in 'libs1' ...
+        findlibs: looking for 'libbar.so' in 'libs2' ...
+      cc -o prog.o -c prog.c
+      cc -o prog prog.o -Llibs1 -Llibs2 -lfoo -lbar
+    </screen>
+
+  </section>
+
+  <!--
+
+  <section>
+
+  <title>What Implicit Dependencies Did the &SCons; Scanner find?  the &debug-includes; Option</title>
+
+    <para>
+
+    XXX explain the - - debug=includes option
+
+    </para>
+
+    <scons_example name="includes">
+      <file name="SConstruct" printme="1">
+        env = Environment(CPPPATH = ['inc1', 'inc2'])
+        env.Program('prog.c')
+      </file>
+      <file name="prog.c">
+      #include "file1.h"
+      #include "file2.h"
+      prog.c
+      </file>
+      <file name="inc1/file1.h">
+      inc1/file1.h
+      </file>
+      <file name="inc2/file2.h">
+      inc2/file2.h
+      </file>
+    </scons_example>
+
+    <scons_output example="includes">
+      <scons_output_command>scons -Q - - debug=includes prog</scons_output_command>
+    </scons_output>
+
+  </section>
+
+  -->
+
+  <section>
+
+  <title>Where is &SCons; Blowing Up?  the &debug-stacktrace; Option</title>
+
+    <para>
+
+    In general, &SCons; tries to keep its error
+    messages short and informative.
+    That means we usually try to avoid showing
+    the stack traces that are familiar
+    to experienced Python programmers,
+    since they usually contain much more
+    information than is useful to most people.
+
+    </para>
+
+    <para>
+
+    For example, the following &SConstruct; file:
+
+    </para>
+
+    <programlisting>
+         Program('prog.c')
+    </programlisting>
+
+    <para>
+
+    Generates the following error if the
+    <filename>prog.c</filename> file
+    does not exist:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q</userinput>
+      scons: *** [prog.o] Source `prog.c' not found, needed by target `prog.o'.
+    </screen>
+
+    <para>
+
+    In this case,
+    the error is pretty obvious.
+    But if it weren't,
+    and you wanted to try to get more information
+    about the error,
+    the &debug-stacktrace; option
+    would show you exactly where in the &SCons; source code
+    the problem occurs:
+
+    </para>
+
+    <screen>
+      % <userinput>scons -Q --debug=stacktrace</userinput>
+      scons: *** [prog.o] Source `prog.c' not found, needed by target `prog.o'.
+      scons: internal stack trace:
+        File "bootstrap/src/engine/SCons/Job.py", line 197, in start
+        File "bootstrap/src/engine/SCons/Script/Main.py", line 167, in prepare
+        File "bootstrap/src/engine/SCons/Taskmaster.py", line 190, in prepare
+        File "bootstrap/src/engine/SCons/Executor.py", line 397, in prepare
+    </screen>
+
+    <para>
+
+    Of course, if you do need to dive into the &SCons; source code,
+    we'd like to know if, or how,
+    the error messages or troubleshooting options
+    could have been improved to avoid that.
+    Not everyone has the necessary time or
+    Python skill to dive into the source code,
+    and we'd like to improve &SCons;
+    for those people as well...
+
+    </para>
+
+  </section>
+
+  <section>
+
+  <title>How is &SCons; Making Its Decisions?  the &taskmastertrace; Option</title>
+
+    <para>
+
+    The internal &SCons; subsystem that handles walking
+    the dependency graph
+    and controls the decision-making about what to rebuild
+    is the <literal>Taskmaster</literal>.
+    &SCons; supports a <literal>--taskmastertrace</literal>
+    option that tells the Taskmaster to print
+    information about the children (dependencies)
+    of the various Nodes on its walk down the graph,
+    which specific dependent Nodes are being evaluated,
+    and in what order.
+
+    </para>
+
+    <para>
+
+    The <literal>--taskmastertrace</literal> option
+    takes as an argument the name of a file in
+    which to put the trace output,
+    with <filename>-</filename> (a single hyphen)
+    indicating that the trace messages
+    should be printed to the standard output:
+
+    </para>
+
+    <programlisting>
+      env = Environment(CPPPATH = ['.'])
+      env.Program('prog.c')
+    </programlisting>
+
+    <screen>
+      % <userinput>scons -Q --taskmastertrace=- prog</userinput>
+      
+      Taskmaster: Looking for a node to evaluate
+      Taskmaster:     Considering node &lt;no_state   0   'prog'&gt; and its children:
+      Taskmaster:        &lt;no_state   0   'prog.o'&gt;
+      Taskmaster:      adjusted ref count: &lt;pending    1   'prog'&gt;, child 'prog.o'
+      Taskmaster:     Considering node &lt;no_state   0   'prog.o'&gt; and its children:
+      Taskmaster:        &lt;no_state   0   'prog.c'&gt;
+      Taskmaster:        &lt;no_state   0   'inc.h'&gt;
+      Taskmaster:      adjusted ref count: &lt;pending    1   'prog.o'&gt;, child 'prog.c'
+      Taskmaster:      adjusted ref count: &lt;pending    2   'prog.o'&gt;, child 'inc.h'
+      Taskmaster:     Considering node &lt;no_state   0   'prog.c'&gt; and its children:
+      Taskmaster: Evaluating &lt;pending    0   'prog.c'&gt;
+      
+      Task.make_ready_current(): node &lt;pending    0   'prog.c'&gt;
+      Task.prepare():      node &lt;up_to_date 0   'prog.c'&gt;
+      Task.executed_with_callbacks(): node &lt;up_to_date 0   'prog.c'&gt;
+      Task.postprocess():  node &lt;up_to_date 0   'prog.c'&gt;
+      Task.postprocess():  removing &lt;up_to_date 0   'prog.c'&gt;
+      Task.postprocess():  adjusted parent ref count &lt;pending    1   'prog.o'&gt;
+      
+      Taskmaster: Looking for a node to evaluate
+      Taskmaster:     Considering node &lt;no_state   0   'inc.h'&gt; and its children:
+      Taskmaster: Evaluating &lt;pending    0   'inc.h'&gt;
+      
+      Task.make_ready_current(): node &lt;pending    0   'inc.h'&gt;
+      Task.prepare():      node &lt;up_to_date 0   'inc.h'&gt;
+      Task.executed_with_callbacks(): node &lt;up_to_date 0   'inc.h'&gt;
+      Task.postprocess():  node &lt;up_to_date 0   'inc.h'&gt;
+      Task.postprocess():  removing &lt;up_to_date 0   'inc.h'&gt;
+      Task.postprocess():  adjusted parent ref count &lt;pending    0   'prog.o'&gt;
+      
+      Taskmaster: Looking for a node to evaluate
+      Taskmaster:     Considering node &lt;pending    0   'prog.o'&gt; and its children:
+      Taskmaster:        &lt;up_to_date 0   'prog.c'&gt;
+      Taskmaster:        &lt;up_to_date 0   'inc.h'&gt;
+      Taskmaster: Evaluating &lt;pending    0   'prog.o'&gt;
+      
+      Task.make_ready_current(): node &lt;pending    0   'prog.o'&gt;
+      Task.prepare():      node &lt;executing  0   'prog.o'&gt;
+      Task.execute():      node &lt;executing  0   'prog.o'&gt;
+      cc -o prog.o -c -I. prog.c
+      Task.executed_with_callbacks(): node &lt;executing  0   'prog.o'&gt;
+      Task.postprocess():  node &lt;executed   0   'prog.o'&gt;
+      Task.postprocess():  removing &lt;executed   0   'prog.o'&gt;
+      Task.postprocess():  adjusted parent ref count &lt;pending    0   'prog'&gt;
+      
+      Taskmaster: Looking for a node to evaluate
+      Taskmaster:     Considering node &lt;pending    0   'prog'&gt; and its children:
+      Taskmaster:        &lt;executed   0   'prog.o'&gt;
+      Taskmaster: Evaluating &lt;pending    0   'prog'&gt;
+      
+      Task.make_ready_current(): node &lt;pending    0   'prog'&gt;
+      Task.prepare():      node &lt;executing  0   'prog'&gt;
+      Task.execute():      node &lt;executing  0   'prog'&gt;
+      cc -o prog prog.o
+      Task.executed_with_callbacks(): node &lt;executing  0   'prog'&gt;
+      Task.postprocess():  node &lt;executed   0   'prog'&gt;
+      
+      Taskmaster: Looking for a node to evaluate
+      Taskmaster: No candidate anymore.
+    </screen>
+
+    <para>
+
+    The <literal>--taskmastertrace</literal> option
+    doesn't provide information about the actual
+    calculations involved in deciding if a file is up-to-date,
+    but it does show all of the dependencies
+    it knows about for each Node,
+    and the order in which those dependencies are evaluated.
+    This can be useful as an alternate way to determine
+    whether or not your &SCons; configuration,
+    or the implicit dependency scan,
+    has actually identified all the correct dependencies
+    you want it to.
+
+    </para>
+
+  </section>
+
+  <!--
+
+  <section>
+
+  <title>Where Are My Build Bottlenecks?  the &profile; Option</title>
+
+    <para>
+
+    XXX explain the - - profile= option
+
+    </para>
+
+  </section>
+
+  -->
+
+  <!--
+
+  <section>
+  <title>Troubleshooting Shared Caching:  the &cache-debug; Option</title>
+
+    <para>
+
+    XXX describe the - - cache-debug option
+    XXX maybe point to the caching.in chapter?
+
+    </para>
+
+  </section>
+
+  -->
diff --git a/doc/user/variables.in b/doc/user/variables.in
new file mode 100644
index 0000000..85fb9cd
--- /dev/null
+++ b/doc/user/variables.in
@@ -0,0 +1,56 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<para>
+
+This appendix contains descriptions of all of the
+construction variables that are <emphasis>potentially</emphasis>
+available "out of the box" in this version of SCons.
+Whether or not setting a construction variable
+in a construction environment
+will actually have an effect depends on
+whether any of the Tools and/or Builders
+that use the variable have been
+included in the construction environment.
+
+</para>
+
+<para>
+
+In this appendix, we have
+appended the initial <envar>$</envar>
+(dollar sign) to the beginning of each
+variable name when it appears in the text,
+but left off the dollar sign
+in the left-hand column
+where the name appears for each entry.
+
+</para>
+
+<variablelist>
+
+&variables-gen;
+
+</variablelist>
diff --git a/doc/user/variables.xml b/doc/user/variables.xml
new file mode 100644
index 0000000..85fb9cd
--- /dev/null
+++ b/doc/user/variables.xml
@@ -0,0 +1,56 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<para>
+
+This appendix contains descriptions of all of the
+construction variables that are <emphasis>potentially</emphasis>
+available "out of the box" in this version of SCons.
+Whether or not setting a construction variable
+in a construction environment
+will actually have an effect depends on
+whether any of the Tools and/or Builders
+that use the variable have been
+included in the construction environment.
+
+</para>
+
+<para>
+
+In this appendix, we have
+appended the initial <envar>$</envar>
+(dollar sign) to the beginning of each
+variable name when it appears in the text,
+but left off the dollar sign
+in the left-hand column
+where the name appears for each entry.
+
+</para>
+
+<variablelist>
+
+&variables-gen;
+
+</variablelist>
diff --git a/doc/user/variants.in b/doc/user/variants.in
new file mode 100644
index 0000000..696e174
--- /dev/null
+++ b/doc/user/variants.in
@@ -0,0 +1,151 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 Variant builds
+
+=head2 Variations on a theme
+
+Other variations of this model are possible. For example, you might decide
+that you want to separate out your include files into platform dependent and
+platform independent files. In this case, you'd have to define an
+alternative to C<$INCLUDE> for platform-dependent files. Most F<Conscript>
+files, generating purely platform-independent include files, would not have
+to change.
+
+You might also want to be able to compile your whole system with debugging
+or profiling, for example, enabled. You could do this with appropriate
+command line options, such as C<DEBUG=on>. This would then be translated
+into the appropriate platform-specific requirements to enable debugging
+(this might include turning off optimization, for example). You could
+optionally vary the name space for these different types of systems, but, as
+we'll see in the next section, it's not B<essential> to do this, since Cons
+is pretty smart about rebuilding things when you change options.
+
+-->
+
+  <para>
+
+  The &variant_dir; keyword argument of
+  the &SConscript; function provides everything
+  we need to show how easy it is to create
+  variant builds using &SCons;.
+  Suppose, for example, that we want to
+  build a program for both Windows and Linux platforms,
+  but that we want to build it in a shared directory
+  with separate side-by-side build directories
+  for the Windows and Linux versions of the program.
+
+  </para>
+
+  <scons_example name="ex_variants">
+    <file name="SConstruct" printme="1">
+    platform = ARGUMENTS.get('OS', Platform())
+
+    include = "#export/$PLATFORM/include"
+    lib = "#export/$PLATFORM/lib"
+    bin = "#export/$PLATFORM/bin"
+
+    env = Environment(PLATFORM = platform,
+                      BINDIR = bin,
+                      INCDIR = include,
+                      LIBDIR = lib,
+                      CPPPATH = [include],
+                      LIBPATH = [lib],
+                      LIBS = 'world')
+
+    Export('env')
+
+    env.SConscript('src/SConscript', variant_dir='build/$PLATFORM')
+    </file>
+    <directory name="src"></directory>
+    <directory name="src/hello"></directory>
+    <directory name="src/world"></directory>
+    <file name="src/SConscript">
+    Import('env')
+    SConscript('hello/SConscript')
+    SConscript('world/SConscript')
+    </file>
+    <file name="src/hello/SConscript">
+    Import('env')
+    hello = env.Program('hello.c')
+    env.Install('$BINDIR', hello)
+    </file>
+    <file name="src/hello/hello.c">
+    #include "world.h"
+    int main(int argc, char *argv[]) { printf "hello.c\n"; world(); }
+    </file>
+    <file name="src/world/SConscript">
+    Import('env')
+    world = env.Library('world.c')
+    env.Install('$LIBDIR', world)
+    env.Install('$INCDIR', 'world.h')
+    </file>
+    <file name="src/world/world.h">
+    #define STRING "world.h"
+    extern int world();
+    </file>
+    <file name="src/world/world.c">
+    int world() { printf "world.c\n"; }
+    </file>
+  </scons_example>
+
+  <para>
+
+  This SConstruct file,
+  when run on a Linux system, yields:
+
+  </para>
+
+  <scons_output example="ex_variants" os="posix">
+    <scons_output_command>scons -Q OS=linux</scons_output_command>
+  </scons_output>
+
+  <para>
+
+  The same SConstruct file on Windows would build:
+
+  </para>
+
+  <scons_output example="ex_variants" os="win32">
+    <scons_output_command>scons -Q OS=windows</scons_output_command>
+  </scons_output>
+
+  <!--
+
+  <scons_example name="ex_var2">
+    <file name="SConstruct" printme="1">
+    env = Environment(OS = ARGUMENTS.get('OS'))
+    for os in ['newell', 'post']:
+        SConscript('src/SConscript', variant_dir='build/' + os)
+    </file>
+  </scons_example>
+
+  <scons_output example="ex_var2">
+    <scons_output_command>scons -Q</scons_output_command>
+  </scons_output>
+
+  -->
diff --git a/doc/user/variants.xml b/doc/user/variants.xml
new file mode 100644
index 0000000..016202a
--- /dev/null
+++ b/doc/user/variants.xml
@@ -0,0 +1,146 @@
+<!--
+
+  Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 The SCons Foundation
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be included
+  in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+  KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+  WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-->
+
+<!--
+
+=head1 Variant builds
+
+=head2 Variations on a theme
+
+Other variations of this model are possible. For example, you might decide
+that you want to separate out your include files into platform dependent and
+platform independent files. In this case, you'd have to define an
+alternative to C<$INCLUDE> for platform-dependent files. Most F<Conscript>
+files, generating purely platform-independent include files, would not have
+to change.
+
+You might also want to be able to compile your whole system with debugging
+or profiling, for example, enabled. You could do this with appropriate
+command line options, such as C<DEBUG=on>. This would then be translated
+into the appropriate platform-specific requirements to enable debugging
+(this might include turning off optimization, for example). You could
+optionally vary the name space for these different types of systems, but, as
+we'll see in the next section, it's not B<essential> to do this, since Cons
+is pretty smart about rebuilding things when you change options.
+
+-->
+
+  <para>
+
+  The &variant_dir; keyword argument of
+  the &SConscript; function provides everything
+  we need to show how easy it is to create
+  variant builds using &SCons;.
+  Suppose, for example, that we want to
+  build a program for both Windows and Linux platforms,
+  but that we want to build it in a shared directory
+  with separate side-by-side build directories
+  for the Windows and Linux versions of the program.
+
+  </para>
+
+  <programlisting>
+    platform = ARGUMENTS.get('OS', Platform())
+
+    include = "#export/$PLATFORM/include"
+    lib = "#export/$PLATFORM/lib"
+    bin = "#export/$PLATFORM/bin"
+
+    env = Environment(PLATFORM = platform,
+                      BINDIR = bin,
+                      INCDIR = include,
+                      LIBDIR = lib,
+                      CPPPATH = [include],
+                      LIBPATH = [lib],
+                      LIBS = 'world')
+
+    Export('env')
+
+    env.SConscript('src/SConscript', variant_dir='build/$PLATFORM')
+  </programlisting>
+
+  <para>
+
+  This SConstruct file,
+  when run on a Linux system, yields:
+
+  </para>
+
+  <screen>
+    % <userinput>scons -Q OS=linux</userinput>
+    Install file: "build/linux/world/world.h" as "export/linux/include/world.h"
+    cc -o build/linux/hello/hello.o -c -Iexport/linux/include build/linux/hello/hello.c
+    cc -o build/linux/world/world.o -c -Iexport/linux/include build/linux/world/world.c
+    ar rc build/linux/world/libworld.a build/linux/world/world.o
+    ranlib build/linux/world/libworld.a
+    Install file: "build/linux/world/libworld.a" as "export/linux/lib/libworld.a"
+    cc -o build/linux/hello/hello build/linux/hello/hello.o -Lexport/linux/lib -lworld
+    Install file: "build/linux/hello/hello" as "export/linux/bin/hello"
+  </screen>
+
+  <para>
+
+  The same SConstruct file on Windows would build:
+
+  </para>
+
+  <screen>
+    C:\><userinput>scons -Q OS=windows</userinput>
+    
+    scons: warning: No installed VCs
+    File "&lt;stdin&gt;", line 67, in __call__
+    
+    scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+    File "&lt;stdin&gt;", line 67, in __call__
+    
+    scons: warning: No installed VCs
+    File "&lt;stdin&gt;", line 67, in __call__
+    
+    scons: warning: No version of Visual Studio compiler found - C/C++ compilers most likely not set correctly
+    File "&lt;stdin&gt;", line 67, in __call__
+    Install file: "build/windows/world/world.h" as "export/windows/include/world.h"
+    cl /Fobuild\windows\hello\hello.obj /c build\windows\hello\hello.c /nologo /Iexport\windows\include
+    cl /Fobuild\windows\world\world.obj /c build\windows\world\world.c /nologo /Iexport\windows\include
+    lib /nologo /OUT:build\windows\world\world.lib build\windows\world\world.obj
+    Install file: "build/windows/world/world.lib" as "export/windows/lib/world.lib"
+    link /nologo /OUT:build\windows\hello\hello.exe /LIBPATH:export\windows\lib world.lib build\windows\hello\hello.obj
+    Install file: "build/windows/hello/hello.exe" as "export/windows/bin/hello.exe"
+  </screen>
+
+  <!--
+
+  <scons_example name="ex_var2">
+    <file name="SConstruct" printme="1">
+    env = Environment(OS = ARGUMENTS.get('OS'))
+    for os in ['newell', 'post']:
+        SConscript('src/SConscript', variant_dir='build/' + os)
+    </file>
+  </scons_example>
+
+  <scons_output example="ex_var2">
+    <scons_output_command>scons -Q</scons_output_command>
+  </scons_output>
+
+  -->