Facebook - Connect with friends, family and other people you know. Share photos and videos, send messages and get updates.
Gab - Gab is an ad-free social network dedicated to free speech.
Friendica - Decentralisation - Privacy - Interoperability
Discourse - Discourse is an open source discussion platform built for the next decade of the Internet.
Mastodon - Mastodon is a decentralized, open source social network. This is just one part of the network, run by the main developers of the project It is not focused on any particular niche interest - everyone is welcome!
Tumblr - A feature rich and free blog hosting platform offering professional and fully customizable templates, bookmarklets, photos, mobile apps, and social network integration.