pypa/virtualenv — comment on commit 85426cf2928ed11e07f9c7460e99d90311e71127
File:  line 0
By zart:

I'm working on fix to support PyPy on Windows. I fixed this code adding

if is_jython or is_pypy:
cmd.remove('-x')

Proper jython/pypy/ironpython support involves more then that though.
As of version support - virtualenv works on CPython 2.4 for me.