Mastodon

Mastodon is a free, open-source social network server based on ActivityPub, where users can follow friends and discover new ones. Users can publish text, links, pictures, and video, and every Mastodon server is part of a federated network that interoperates with other software implementing ActivityPub, known as the Fediverse. It includes real-time timelines, media attachments, and built-in safety and moderation tools such as private posts, locked accounts, and phrase filtering.