I did not know that ANSOL has a Gitea instance, I added a link to https://git.ansol.org/ in the pad. Here is a short recommendation. It is not much but that’s what I can provide before the deadline 
Dear NLnet,
Software Forges are used by most Free Software developers but do not, unfortunately, communicate with each other. In the past few years work started to change that status quo and NLnet funded an effort to that end in Gitea.
Unfortunately the efforts to federate GitLab are at a standstill. It is however the most popular self hostable Free Software forge and implementing ActivityPub could have a major impact.
Hugo Peixoto https://hugopeixoto.net/ is both a Ruby developer and a long time activist involved in ANSOL, a Portugal based non-profit dedicated to Free Software. His willingness to engage in a work to implement ActivityPub in GitLab is a rare opportunity and allowing him move forward with financial support would be a great move.
Loïc Dachary - Free Software developer working on implementing federation features in Forgejo