Sub interpreters are still faster than processes. With them you could do continuation message passing which other modern languages, such as go, use for multi-th

Sub interpreters are still faster than processes. With them you could do continuation message passing which other modern languages, such as go, use for multi-threading. Also, for cases such as web apps or data science training, you don't need to share memory between threads, and a sub interpreter uses a lot less resources than a full python process. > Even if it breaks the c interface Than most of your python packages wouldn't work. A python that isn't backwards compatible? Ya, that has been tried once before, and was a disaster. If you want a non-backwards compatible gil-less python, it already exists. You can find versions of nogil online.