Indirectly related to Drupal as https://git.drupalcode.org/ uses GitLab and there is already an active ActivityPub using Drupal community at https://drupal.community/about
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.
Before starting implementing cross-instance merge requests, we want to start with smaller steps, helping us to build up domain knowledge about ActivityPub and creating the underlying architecture that will support the more advanced features. For that reason, we propose to start with implementing social features, allowing people on the Fediverse to subscribe to activities on GitLab, for example to be notified on their social network of choice when their favorite project hosted on GitLab makes a new release. As a bonus, this is an opportunity to make GitLab more social and grow its audience.