activitypub.org 891 B
ActivityPub
Overview: Activity Pub is designed for federated social networking sites! It uses ActivityStreams. It allows clients to delete, upload, and edit content. It also provides a server to server API that can deliver notifications and content.
So if two users knew each other, then one would look at the other's photo, like it. Her machine (client) would talk to the server. That server would send a message to the other server. That server would notify the other person.
ActivityPub is one of several related specifications being produced by the Social Web Working Group. Implementers interested in alternative approaches and complementary protocols should review [Micropub] and the overview document [Social-Web-Protocols].