Mastodon

Mastodon is a decentralized, open-source social network that works similar to Twitter. It allows users to share short messages called "toots". 

What currently makes Mastodon different from other social networks is that instead of one centralized server, Mastodon is built on a network of servers, each of which can host its own community. 

Users of a community are able to interact with each other regardless of which server they are on. This means there is no single point of control or censorship and users have more control over their data. 

Posts can also contain rich media, like images and videos. Mastodon uses the ActivityPub protocol to federate between servers and enables users to follow each other, boost posts (similar to retweets), and create customizable profiles.