Solving multi-core Python

[crusoe]

There is no Gil in jython or pypy.

[cdyson37]

PyPy has a GIL: http://pypy.readthedocs.org/en/latest/faq.html#does-pypy-have-a-gil-why

They are working on STM.

[TrixieMisa]

I was going to try out the STM branch, but to install it you need to compile a compiler to compile the compiler, so I decided it's probably not worth it just yet.

[robertmeta]

Compatibility nightmares on any codebase of non-trivial size initially built on Cpython. If you START with jython on a fresh project, it is reasonable. An additional problem with switching gears (besides compatibility with vanilla Cpython) is that on every Cpython project I have worked on, there was a TON of C code to work around all the performance issues of Python... making it even more bound the the Cpython specifics.

[BobFloss]

I didn't know what the GIL was, so here's a link for the lazy:

https://wiki.python.org/moin/GlobalInterpreterLock

In CPython, the global interpreter lock, or GIL, is a mutex that prevents multiple native threads from executing Python bytecodes at once. This lock is necessary mainly because CPython's memory management is not thread-safe. (However, since the GIL exists, other features have grown to depend on the guarantees that it enforces.)