PyPy also has a GIL. Their proposal to get rid of it (PyPy STM) is far from being ready for production and comes with a pretty important overhead: http://pypy.r

PyPy also has a GIL. Their proposal to get rid of it (PyPy STM) is far from being ready for production and comes with a pretty important overhead: http://pypy.readthedocs.org/en/latest/stm.html#introduction http://pypy.readthedocs.org/en/latest/stm.html#introduction (but it's a really promising project that all Python developers should follow!)