Some alternative forge are built with decentralization in mind:

- forgejo [1] is working on ForgeFed [2], an extension of ActivityPub (the protocol made popular by Mastodon)

- tangled is built on top of ATproto (the protocol behind Bluesky) [3]

- radicle is rolling their own protocol, more peer-to-peer than federated [4]

- fossil is a broader all-in-one solution: not only a new Version Control System (a replacement for git), but also a forge (has the features of a forge: issues (bug-tracking), PRs, comments, wikis, ...) [5]

The other self-hosted forges such as gitlab, sourcehut, gitea don't have such a high level of decentralization and resilience. It does not make them less good, they are solving different problems, mainly being a easy-to-use self-hosted alternative to proprietary forges. For instance Gitea has Gitea Actions, which is designed to be compatible with GitHub Actions [6], while I don't think running CI/CD workflow in a decentralized way will the priority of projects like tangled or radicle.

[1] https://forgejo.org/faq/#is-there-a-roadmap-for-forgejo

[2] https://forgefed.org/

[3] https://tangled.org/

[4] https://radicle.dev/guides/protocol#federation-vs-peer-to-pe...

[5] https://fossil-scm.org/home/doc/trunk/www/index.wiki

[6] https://docs.gitea.com/usage/actions/overview