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

Oh, never mind, `-x` *has* been around forever, you meant that `platform.python_implementation` is recent. Yeah, we don't need that, I have no problem just using `is_pypy` and `is_jython` which we already have.