Packages built on Raven's core libraries that sit outside the 1.0 commitment. Each one is its own dune project with its own version and opam metadata. fehu, sowilo and ymir keep their own CHANGES.md.

Package	What it does
fehu	Reinforcement learning environments
sowilo	Differentiable computer vision
ymir	Astronomy: units, frames, FITS, photometry, cosmology

Policy #

Contrib packages build and test against main in CI. A change to a core library that breaks a contrib package fixes it in the same commit.
They carry no API stability guarantee and release on their own schedule. opam install raven does not install them.
They depend only on the public libraries of core packages, with a lower bound on the oldest core release they build against.
Each package names its maintainers in its dune-project.