> I didn't add Cython because it's not clear to me if it's useful for creating extension modules in a pythonesque language, or if it's also useful by it's own.

Cython only makes extensions for CPython, and uses CPython's runtime. But it does have its own syntax, which is quite useful in the number-crunching domain.

I think it should be left out, but then, so should VPython which seems like it's a module usable by either the CPython or RapydScript interpreters.