diff --git a/Lib/distutils/extension.py b/Lib/distutils/extension.py
new file mode 100644
index 0000000..9d2a6fa
--- /dev/null
+++ b/Lib/distutils/extension.py
@@ -0,0 +1,115 @@
+"""distutils.extension
+
+Provides the Extension class, used to describe C/C++ extension
+modules in setup scripts."""
+
+# created 2000/05/30, Greg Ward
+
+__revision__ = "$Id$"
+
+from types import *
+
+
+# This class is really only used by the "build_ext" command, so it might
+# make sense to put it in distutils.command.build_ext.  However, that
+# module is already big enough, and I want to make this class a bit more
+# complex to simplify some common cases ("foo" module in "foo.c") and do
+# better error-checking ("foo.c" actually exists).
+# 
+# Also, putting this in build_ext.py means every setup script would have to
+# import that large-ish module (indirectly, through distutils.core) in
+# order to do anything.
+
+class Extension:
+    """Just a collection of attributes that describes an extension
+    module and everything needed to build it (hopefully in a portable
+    way, but there are hooks that let you can be as unportable as you
+    need).
+
+    Instance attributes:
+      name : string
+        the full name of the extension, including any packages -- ie.
+        *not* a filename or pathname, but Python dotted name
+      sources : [string]
+        list of C/C++ source filenames, relative to the distribution
+        root (where the setup script lives), in Unix form
+        (slash-separated) for portability
+      include_dirs : [string]
+        list of directories to search for C/C++ header files (in Unix
+        form for portability)
+      define_macros : [(name : string, value : string|None)]
+        list of macros to define; each macro is defined using a 2-tuple,
+        where 'value' is either the string to define it to or None to
+        define it without a particular value (equivalent of "#define
+        FOO" in source or -DFOO on Unix C compiler command line)
+      undef_macros : [string]
+        list of macros to undefine explicitly
+      library_dirs : [string]
+        list of directories to search for C/C++ libraries at link time
+      libraries : [string]
+        list of library names (not filenames or paths) to link against
+      runtime_library_dirs : [string]
+        list of directories to search for C/C++ libraries at run time
+        (for shared extensions, this is when the extension is loaded)
+      extra_objects : [string]
+        list of extra files to link with (eg. object files not implied
+        by 'sources', static library that must be explicitly specified,
+        binary resource files, etc.)
+      extra_compile_args : [string]
+        any extra platform- and compiler-specific information to use
+        when compiling the source files in 'sources'.  For platforms and
+        compilers where "command line" makes sense, this is typically a
+        list of command-line arguments, but for other platforms it could
+        be anything.
+      extra_link_args : [string]
+        any extra platform- and compiler-specific information to use
+        when linking object files together to create the extension (or
+        to create a new static Python interpreter).  Similar
+        interpretation as for 'extra_compile_args'.
+      export_symbols : [string]
+        list of symbols to be exported from a shared extension.  Not
+        used on all platforms, and not generally necessary for Python
+        extensions, which typically export exactly one symbol: "init" +
+        extension_name.
+      export_symbol_file : string
+        name of file that lists symbols to export; the format of this
+        file is platform- and compiler-specific.  This is even more
+        gratuitous and unnecessary than 'export_symbols'; I'll be happy
+        when it goes away forever.
+    """
+
+    def __init__ (self, name, sources,
+                  include_dirs=None,
+                  define_macros=None,
+                  undef_macros=None,
+                  library_dirs=None,
+                  libraries=None,
+                  runtime_library_dirs=None,
+                  extra_objects=None,
+                  extra_compile_args=None,
+                  extra_link_args=None,
+                  export_symbols=None,
+                  export_symbol_file=None,
+                 ):
+
+        assert type(name) is StringType, "'name' must be a string"
+        assert (type(sources) is ListType and
+                len(sources) >= 1 and
+                map(type, sources) == [StringType]*len(sources)), \
+                "'sources' must be a non-empty list of strings"
+
+        self.name = name
+        self.sources = sources
+        self.include_dirs = include_dirs or []
+        self.define_macros = define_macros or []
+        self.undef_macros = undef_macros or []
+        self.library_dirs = library_dirs or []
+        self.libraries = libraries or []
+        self.runtime_library_dirs = runtime_library_dirs or []
+        self.extra_objects = extra_objects or []
+        self.extra_compile_args = extra_compile_args or []
+        self.extra_link_args = extra_link_args or []
+        self.export_symbols = export_symbols or []
+        self.export_symbol_file = export_symbol_file
+
+# class Extension