39
Alright, let's Fedify
(activitypub.ghost.org)
A community dedicated to fediverse news and discussion.
Fediverse is a portmanteau of "federation" and "universe".
Getting started on Fediverse;
TL;DR — Ghost started out as a WordPress alternative but gradually moved to focus on newsletter formats (at which point, see u/maegul's reply), and the dev team have worked on implementing ActivityPub for a good while now.
From what I can tell Ghost is a really mature project with a lot of traction. I think having a federated newsletter platform is an interesting addition to the fediverse.