Wait, forgejo offers a built-in container registry? How does that work? I don't see that in the admin section at all.

Container registry and a lot more, they call it Package registry in the docs https://forgejo.org/docs/latest/user/packages/

Just run podman or docker login your.forgejo.instance.address then push to it as normal. An existing repo must exist. You can check the images under site administration -> packages.

Speaking of authentication it also works as an openid provider meaning you can authenticate every other web software that supports it to Forgejo... which in turn can look for users in other sources.

It also has wikis.

Its an underrated piece of software that uses a ridiculous small amount of computer resources.