Index: setuptools/extension.py
===================================================================
--- setuptools/extension.py	(revision 75864)
+++ setuptools/extension.py	(working copy)
@@ -28,6 +28,11 @@
 class Library(Extension):
     """Just like a regular Extension, but built as a library instead"""
 
+    def __init__(self, *args, **kwds):
+        self.force_shared = kwds.pop('force_shared', False)
+        Extension.__init__(self, *args, **kwds)
+
+
 import sys, distutils.core, distutils.extension
 distutils.core.Extension = Extension
 distutils.extension.Extension = Extension
Index: setuptools/command/build_ext.py
===================================================================
--- setuptools/command/build_ext.py	(revision 75864)
+++ setuptools/command/build_ext.py	(working copy)
@@ -85,8 +85,12 @@
         if fullname in self.ext_map:
             ext = self.ext_map[fullname]
             if isinstance(ext,Library):
+                if ext.force_shared and not use_stubs:
+                    _libtype = 'shared'
+                else:
+                    _libtype = libtype
                 fn, ext = os.path.splitext(filename)
-                return self.shlib_compiler.library_filename(fn,libtype)
+                return self.shlib_compiler.library_filename(fn,_libtype)
             elif use_stubs and ext._links_to_dynamic:
                 d,fn = os.path.split(filename)
                 return os.path.join(d,'dl-'+fn)
@@ -170,14 +174,22 @@
     def build_extension(self, ext):
         _compiler = self.compiler
         try:
+            force_shared = False
             if isinstance(ext,Library):
                 self.compiler = self.shlib_compiler
+                force_shared = ext.force_shared and not use_stubs
+                if force_shared:
+                    self.compiler.link_shared_object = \
+                        sh_link_shared_object.__get__(self.compiler)
             _build_ext.build_extension(self,ext)
             if ext._needs_stub:
                 self.write_stub(
                     self.get_finalized_command('build_py').build_lib, ext
                 )
         finally:
+            if force_shared:
+                self.compiler.link_shared_object = \
+                    link_shared_object.__get__(self.compiler)
             self.compiler = _compiler
 
     def links_to_dynamic(self, ext):
@@ -244,44 +256,41 @@
                 os.unlink(stub_file)
 
 
-if use_stubs or os.name=='nt':
-    # Build shared libraries
-    #
-    def link_shared_object(self, objects, output_libname, output_dir=None,
-        libraries=None, library_dirs=None, runtime_library_dirs=None,
-        export_symbols=None, debug=0, extra_preargs=None,
-        extra_postargs=None, build_temp=None, target_lang=None
-    ):  self.link(
-            self.SHARED_LIBRARY, objects, output_libname,
-            output_dir, libraries, library_dirs, runtime_library_dirs,
-            export_symbols, debug, extra_preargs, extra_postargs,
-            build_temp, target_lang
-        )
-else:
-    # Build static libraries everywhere else
-    libtype = 'static'
+def sh_link_shared_object(self, objects, output_libname, output_dir=None,
+    libraries=None, library_dirs=None, runtime_library_dirs=None,
+    export_symbols=None, debug=0, extra_preargs=None,
+    extra_postargs=None, build_temp=None, target_lang=None
+):  self.link(self.SHARED_LIBRARY, objects, output_libname,
+              output_dir, libraries, library_dirs, runtime_library_dirs,
+              export_symbols, debug, extra_preargs, extra_postargs,
+              build_temp, target_lang)
 
-    def link_shared_object(self, objects, output_libname, output_dir=None,
-        libraries=None, library_dirs=None, runtime_library_dirs=None,
-        export_symbols=None, debug=0, extra_preargs=None,
-        extra_postargs=None, build_temp=None, target_lang=None
-    ):
-        # XXX we need to either disallow these attrs on Library instances,
-        #     or warn/abort here if set, or something...
-        #libraries=None, library_dirs=None, runtime_library_dirs=None,
-        #export_symbols=None, extra_preargs=None, extra_postargs=None,
-        #build_temp=None
+def st_link_shared_object(self, objects, output_libname, output_dir=None,
+    libraries=None, library_dirs=None, runtime_library_dirs=None,
+    export_symbols=None, debug=0, extra_preargs=None,
+    extra_postargs=None, build_temp=None, target_lang=None
+):
+    # XXX we need to either disallow these attrs on Library instances,
+    #     or warn/abort here if set, or something...
+    #libraries=None, library_dirs=None, runtime_library_dirs=None,
+    #export_symbols=None, extra_preargs=None, extra_postargs=None,
+    #build_temp=None
 
-        assert output_dir is None   # distutils build_ext doesn't pass this
-        output_dir,filename = os.path.split(output_libname)
-        basename, ext = os.path.splitext(filename)
-        if self.library_filename("x").startswith('lib'):
-            # strip 'lib' prefix; this is kludgy if some platform uses
-            # a different prefix
-            basename = basename[3:]
+    assert output_dir is None   # distutils build_ext doesn't pass this
+    output_dir,filename = os.path.split(output_libname)
+    basename, ext = os.path.splitext(filename)
+    if self.library_filename("x").startswith('lib'):
+        # strip 'lib' prefix; this is kludgy if some platform uses
+        # a different prefix
+        basename = basename[3:]
 
-        self.create_static_lib(
-            objects, basename, output_dir, debug, target_lang
-        )
+    self.create_static_lib(objects, basename, output_dir, debug, target_lang)
 
 
+if use_stubs or os.name=='nt':
+    # Build shared libraries
+    link_shared_object = sh_link_shared_object
+else:
+    # Build static libraries everywhere else (unless force_shared)
+    libtype = 'static'
+    link_shared_object = st_link_shared_object
