Is it any service that includes the ability to federate? If so, are Matrix/XMPP/other non-ActivityPub services part of the Fediverse, or does Fediverse really just mean ActivityPub?
The context is wanting to promote a Matrix chat room on discuss.online: #online.discuss:discuss.online (see post). Does it belong in Lemmy communities like this one, !fedigrow@lemm.ee, etc? Or does it not count as part of the Fediverse?
Wasn't the Twitter "bridge" just bot accounts though? It's a bit different with Bluesky because they've said that they completely support bridges between AT and AP but just don't have the resources to work on them themselves. Anyway, ActivityPub co-author Evan Prodromou gave an interview yesterday where he included Bluesky as part of the Fediverse because of the bridge.
Personally, I consider them to be both part of and not part of the Fediverse, I guess. I wouldn't send someone there and I also kind of think they're a bunch of dicks for re-inventing the wheel instead of contributing improvements here.