I can’t help but notice most (all I’ve seen anyway) of the federated projects are hosted on GitHub. GitLab is also federated, but can be self hosted and has at least discussed it.
I am fully aware of my bias for GitLab over GitHub, but I still wonder why is those things? Is there a federated source hosting project?
I use github for public projects. Easily discoverable and it works extremely well.
It’s also free for FOSS.
For private/internal, inuse gitea. Very small, lightweight, but works perfectly