An open-source social media platform similar to Twitter, with a federated network of independently operated servers, allowing users to post 'toots' of up to 500 characters.
Mastodon is an open-source, decentralized social networking platform launched in 2016. It operates as an alternative to commercial platforms like Twitter or Facebook by allowing a federated network of independently operated servers to exchange posts between one another.
Rather than having a single central authority like Twitter or Facebook, Mastodon servers can be operated by anyone with access to infrastructure who agrees to participate in the federation protocol. This lack of central control prevents a single entity from unilaterally changing policies or censoring users.
The user experience of Mastodon closely resembles Twitter, allowing short posts of up to 500 characters called 'toots' that can include media attachments. Users can follow other users not just on their home instance but across the entire federated network. Features like hashtags and content warnings for sensitive media function similarly as well.
A key reason for Mastodon's creation was dissatisfaction over the proliferation of hate speech, harassment, and lack of chronological timelines on commercial social media platforms. By making moderation responsibilities decentralized rather than centralized in the hands of a single corporation, Mastodon offers an alternative model for social media governance and policy.