ColdCast - An open social network with zero corporate interference.
GNU social - GNU social is communication software for both public and private communications.
Chttr.co - Chttr.co is a social network with 1. openness — everything is public 2. effortless discussions 3.
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.
Identi.ca - Social & Communications