Friendica - Decentralisation - Privacy - Interoperability
ColdCast - An open social network with zero corporate interference.
Known - Publish blog posts, photos and media to your own site, and syndicate it to your social networks. Keep everything on your own site.
GNU social - GNU social is communication software for both public and private communications.
Gab - Gab is an ad-free social network dedicated to free speech.
Pleroma - Pleroma is a free, federated social networking server built on open protocols.