The initial protocol used by Mastodon, OStatus, used Pubsubhubbub (which is the same thing as WebSub) as it’s realtime delivery method. WebSub is a spec from t

The initial protocol used by Mastodon, OStatus, used Pubsubhubbub (which is the same thing as WebSub) as it’s realtime delivery method. WebSub is a spec from the very same working group that published the ActivityPub spec and WebSub is actively used by eg. the IndieWeb movement that do indeed very much solve social network monopoly as everyone hosts their social profiles themselves there.