[Distutils] Python version numbers and jython, IronPython, PyPy, and ShedSkin (was: setuptools on jython)

[zooko]

If setuptools works on jython, what does it use for the "pyX.Y" part  
of the egg names?

And in the future hopefully IronPython, PyPy, and ShedSkin will join  
the setuptools party.

Does this revive our interest in supporting "100% Pure Python" eggs  
that do not have an X.Y Python version number in their names?  (Since  
Python code without native extension modules is a lot more likely to  
work on various versions of various implementations of Python than  
Python code with native extension modules.)

Or will jython, IronPython, PyPy, and ShedSkin specify some X.Y  
version of CPython that they support?

Regards,

Zooko