We would like to take a moment to talk about the experimental just-in-time compiler in CPython, and the path we think it should take from here.

Over the past several years, several core developers and contributors have been building a JIT compiler in the main branch of CPython. We want to begin by thanking them. This has been hard, deeply technical work that has been done with great care, and the recent performance improvements are real and encouraging. None of what follows is a criticism of that effort or of the people behind it. Quite the opposite. It is precisely because the project has been underway for so long, undergoing several re-architectures, that we think now is a good time to re-evaluate the JIT’s informal status in the project.

When the JIT was originally merged into main, it entered as an experiment, and the only enhancement proposal written about it, PEP 744, is Informational. That PEP did valuable work in explaining the initial design and even sketched the cri