Friendica is a decentralized, self-hostable alternative to Facebook. It has all the basic Facebook functionality (pages, groups, events), and also some neat little features like formatting (using BBCode), a calendar, a dislike button on posts and comments, post titles and other stuff that Meta did not add to it to this day. Friendica is multiprotocol (i.e. supports both ActivityPub and the diaspora protocols) and extensible, with add-ons that allow you to connect to other networks like Bluesky or Tumblr. Friendica also allows you to follow the websites' RSS feeds like regular accounts, with each article posted via RSS appearing in the regular feed.