Mastodon is free and open-source software for running self-hosted social networking services. It has microblogging features similar to Twitter, which are offered by a large number of independently run nodes, known as instances or servers, each with its own code of conduct, terms of service, privacy policy, privacy options, and content moderation policies.
Each user is a member of a specific Mastodon server that can interact seamlessly with users in any other server. This is intended to give users the flexibility to select a server whose policies they prefer, while being able to communicate within a greater federated social network. Mastodon is powered by the ActivityPub protocol, making it a part of the fediverse and able to communicate with other services that support it such as Lemmy, Pixelfed, Misskey, PeerTube and Pleroma.
Mastodon was created by Eugen Rochko and revealed to the public via Hacker News in October 2016. Not long after, it quickly gained popularity and became the dominant platform in the fediverse and overtaking the previous leader, GNU social. It gained significant adoption in 2022 following the acquisition of...