setuptools includes Jython trunk support as of version 0.6c8!

Setuptools trunk and its 0.6 branch have had [http://svn.python.org/view?rev=60062&view=rev a couple of changes] (discussed [http://mail.python.org/pipermail/distutils-sig/2008-January/008617.html here on distutils-sig]) made to fix incompatibilities with Jython.

Even as of these changes, there are a couple improvements that can be made to running setuptools on Jython:

The Jython changes made for setuptools: