Mastodon is an alternative implementation of GNU social, a free,
open-source social network. It is a decentralized alternative to
commercial platforms based on ActivityStreams, Webfinger, PubsubHubbub
and Salmon. The project focuses on creating a clean REST API and a good
user interface. Ruby on Rails is used for the back-end, while React.js
and Redux are used for the dynamic front-end.