Gitter is an instant messaging and chat room system for developers and users of GitHub repositories. Gitter is provided as software-as-a-service, with a free option providing all basic features and the ability to create a single private chat room, and paid subscription options for individuals and organisations, which allows them to create arbitrary numbers of private chat rooms. Gitter is similar to IRC and HipChat. Unlike IRC, and like HipChat, it automatically logs all messages in the cloud.