Late, but still: I dare say that what Mike Macgirvin has done.

Mistpark/Friendika/Friendica looks like and is marketed as a Facebook alternative. But it comes with extra features on top like a built-in file storage, and its actual killer feature has always been that it federates with everything that moves.

Red a.k.a. the Red Matrix used to handle much like Friendica on the surface, but it introduced nomadic identity and permissions as early as 2012.

Hubzilla, into which the Red Matrix was turned in 2015, is probably the most powerful of all Fediverse projects. It was the first Fediverse project to implement ActivityPub, two months before Mastodon. And it was the first nomadic one to actually kind of take off.

Finally, the latest offspring of 14 years (plus two days) of development since Mistpark is the streams repository which isn't as feature-heavy as Hubzilla, but the most innovative one, and it's constantly evolving. It will be there first that nomadic identity and even permissions beyond what Hubzilla has to offer will be implemented in ActivityPub. And it's likely that this will happen this year.