I call it the Activity Pub.
Makes me feel more welcome.

Oh, to be back in the good old days: "It's not Federated!" 🤣
#identica

uh, I thought it was you?

I'd rather give it a more restrictive definition : " all the actually decentralized and independent servers giving access to softwares working on the ActivityPub ". So, that would exclude Threads. And the #Fediverse brings together the #fediversians, the beautiful name of our tribe.