A photograph of a short-eared owl mid-flight was the last Instagram post biology professor Carl Bergstrom shared before announcing his departure from the platform Jan. 10.
Why is ActivityPub “the” Fediverse? “Fediverse” is very broad and encompasses multiple protocols, a lot of which predate ActivityPub becoming commonplace.
The original Fediverse apps are still around and don’t use ActivityPub. For example, StatusNet / GNU Social use OStatus and Identica uses Activity Streams / ActivityPump (which was the protocol before ActivityPub). diaspora (if it’s still around) used its own protocol too.
Some of the older apps have adapted to use ActivityPub, while some of them still exist in their own separate part of the Fediverse.
Because a fediverse is any group of technologies that talk to each other via a common protocol. In 2025 that’s ActivityPub and has been for awhile. It would be one hell of a stretch to assert that a single platform with its own home made protocol that doesn’t talk to any other technology in the entire fediverse as part of that fediverse. So at best you can say Bluesky has its own fediverse. And if one fediverse is going to be “the fediverse” it’s going to be the one that actually connects all the most common platforms people use today, including Diaspora.
A fediverse, but not the fediverse (ActivityPub/the one you’re on right now)
Why is ActivityPub “the” Fediverse? “Fediverse” is very broad and encompasses multiple protocols, a lot of which predate ActivityPub becoming commonplace.
The original Fediverse apps are still around and don’t use ActivityPub. For example, StatusNet / GNU Social use OStatus and Identica uses Activity Streams / ActivityPump (which was the protocol before ActivityPub). diaspora (if it’s still around) used its own protocol too.
Some of the older apps have adapted to use ActivityPub, while some of them still exist in their own separate part of the Fediverse.
Because a fediverse is any group of technologies that talk to each other via a common protocol. In 2025 that’s ActivityPub and has been for awhile. It would be one hell of a stretch to assert that a single platform with its own home made protocol that doesn’t talk to any other technology in the entire fediverse as part of that fediverse. So at best you can say Bluesky has its own fediverse. And if one fediverse is going to be “the fediverse” it’s going to be the one that actually connects all the most common platforms people use today, including Diaspora.