@jaywink @remram44 eh, it's more complicated than that.

Basically, you have five different protocols: ActivityPub, OStatus, Diaspora, DFRN, and Zot. Most apps speak one of those protocols, a few are polyglots.

So, most of the network can speak the same protocol, and largely does so via AP. However, there are pockets within this network that speak different non-AP protocols: all of Diaspora is its own protocol, but Friendica, Hubzilla, and Socialhome can talk to it because they implemented the protocol correctly. Friendica can also do OStatus and DFRN as well as ActivityPub, and Hubzilla can also do Zot in addition to everything else.

So...although the network is largely unified, it remains fragmented for the time being. This is partially why some interpretations of the term "fediverse" have come to refer to "anything that federates" rather than "all systems that federate together through common protocols"