The PyPy FAQ addresses this. To my eyes, it looks like this is partly to provide the same promises CPython does for C extensions, and partly because their tran

The PyPy FAQ addresses this. To my eyes, it looks like this is partly to provide the same promises CPython does for C extensions, and partly because their transactional memory approach hasn't gotten the attention it would need to succeed. I think both of those show CPython stealing the air from PyPy. https://doc.pypy.org/en/latest/faq.html#does-pypy-have-a-gil-why https://doc.pypy.org/en/latest/faq.html#does-pypy-have-a-gil...