The end goal of this proposal is to build interoperability features into GitLab so that it’s possible on one instance of GitLab to open a merge request to a project hosted on an other instance, merging all willing instances in a global network.
To achieve that, we propose to use ActivityPub, the w3c standard used by the Fediverse. This will allow us to build upon a robust and battle-tested protocol, and it will open GitLab to a wider community.
Being able to create issues and discuss merge requests on various source hosting sites without having to create an account on each would be a huge step forward! Especially since M$ has taken over Github and is well on its way to become the defacto centralized Git hoster.