They did. They kicked off the STM project over a decade ago and produced a handful of releases. The project died on the vine: > STM was a research project that

They did. They kicked off the STM project over a decade ago and produced a handful of releases. The project died on the vine: > STM was a research project that proved that the idea is possible. However, the amount of user effort that is required to make programs run in a parallelizable way is significant, and we never managed to develop tools that would help in doing so. At the moment we're not sure if more work spent on tooling would improve the situation or if the whole idea is really doomed. The approach also ended up adding significant overhead on single threaded programs, so in the end it is very easy to make your programs slower. (We have some money left in the donation pot for STM which we are not using; according to the rules, we could declare the STM attempt failed and channel that money towards the present GIL removal proposal.) https://pypy.org/posts/2017/08/lets-remove-global-interpreter-lock-748023554216649595.html https://pypy.org/posts/2017/08/lets-remove-global-interprete...