Unladen has never intended to remove the GIL - their primary goal was to keep compatibility with C extensions without even recompiling IIRC (google seems to rely a lot on python extension around their infrastructure), and removing the GIL will break many, many extensions: the only known way to remove the GIL without cause a huge slow down is to remove reference counting, which C extensions rely on, and also most C extensions rely on the fact they don't need to be reentrant.