The path toward a no-GIL Python

The Python Steering Council has posted a
detailed plan for the addition of 'free-threaded' (no global
interpreter lock) support into the Python mainline. It will not be a short
process and does not have a guaranteed successful outcome.

Phase I: Experimental phase, which can start immediately, in which
the free-threaded build is enabled through a build-time
option. This should not be the default install anywhere. At least
one major Python release should include this experimental
free-threaded build, to allow third-party packages to test and do
their own experimentation. In this stage we should make it clear
the build is experimental, not supported for “production use”, and
may be reverted.