python doesn't scale well with multiple threads/cores[1]. the high level motivation is to fix that. since the GIL is the main source of the problems, that has

python doesn't scale well with multiple threads/cores[1]. the high level motivation is to fix that. since the GIL is the main source of the problems, that has to go. [1] the best current solution is to use the multiprocessing package which runs a completely separate python instance on each core, but obviously that doesn't support simple shared memory access (you can do it, but it's not "natural").