The mission-driven tech company behind the Firefox browser, Pocket reader and other apps is now investing its energy into the so-called “fediverse” — a collection of decentralized social networking applications, like Mastodon, that communicate with one another over the ActivityPub protocol.
Mozilla has been a big advocate for a decentralized web for awhile now. Joining the Fediverse seems like a natural move for them; honestly surprised they didn't do it sooner.