Timeline

2021-06-05 PyMC Timeline

What a year! What started out as a very diffuse outlook has converged to an exciting future for PyMC3: Our backend changed from Theano through Theano-PyMC into Aesara, a next-generation graph computation engine.

This means that exciting features and a few breaking changes are coming to your favorite PPL, PyMC3.

First of all, the 3 in PyMC3 no longer has anything to do with the package version. Better think of it as "PyMC for Python 3" compared to the predecessor "PyMC2".

Depending on the release version, PyMC3 depends on different graph computation backends:

• pymc3 <3.10 depends on Theano
• pymc3 >=3.10,<4 depends on Theano-PyMC
• pymc3 >=4 depends on Aesara

Branches:

• main, formerly known as master. From this branch we make releases of pymc3 >=4.0.0.
• v3 is for backporting critical bugfixes to the "old" PyMC3.

Check the Milestones to find which releases are coming up next.

Contributing

Check out milestones on PyMC3 and Aesara.

• Everything in a vNext milestone has topmost priority.
• Issues outside of milestones are considered "backlog". They don't block a release, but fixing them is still an important contribution!