| Troupe Technology Ltd.|
| Web, Windows, Mac, iOS, Android, Linux|
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.
Individual chat rooms can be created for individual git repositories on GitHub. Chatroom privacy follows the privacy settings of the associated GitHub repository: thus, a chatroom for a private (i.e. members-only) GitHub repository is also private to those with access to the repository. A graphical badge linking to the chat room can then be placed in the git repository's README file, bringing it to the attention of all users and developers of the project. Users can chat in the chat rooms, or access private chat rooms for repositories they have access to, by logging in to Gitter via GitHub (which does not involve sharing the user's GitHub password with Gitter).
Gitter is similar to IRC and Slack. Unlike IRC, and like Slack, it automatically logs all messages in the cloud.
Gitter supports:Notifications, which are batched up on mobile devices to avoid annoyance
Inline media files
Viewing and subscribing to ("starring") multiple chat rooms in one web browser tab
Linking to individual files in the linked git repository
Linking to GitHub issues (by typing # and then the issue number) in the linked git repository, with hovercards showing the details of the issue
GitHub-flavored Markdown in chat messages
Online status for users
User hovercards, based on their GitHub profiles and statistics (number of GitHub followers, etc.)
Browsable and searchable message archives, grouped by month
Connection from IRC clients
Gitter integrates with Trello, Jenkins, Travis CI, Heroku, Sentry, Bitbucket, HuBoard, Logentries, Pagerduty and Sprintly.
Official Gitter apps for Windows, Mac, Linux, iOS and Android are available.
Like other chat technologies, Gitter allows users and developers to collaborate in real-time (both users with developers, and developers with each other) and to share information on evolving best practices. Because of its integration with Github authentication and its web-based chat client, it is easy and convenient for users and developers to join a chat room without needing to install any extra software, or create another username/password pair to remember. (Though web-based IRC clients exist, they are typically not as fully featured as standard IRC clients and not as widely used among software developers.) It is also convenient for project owners to set up a chat room, because of the GitHub integration - and for private repositories, they do not need to manually grant access to the chat room to all those who have access to the repository, because Gitter does that automatically.
The fact that messages posted to Gitter chat rooms are preserved indefinitely in chat room logs means that all users can see all messages in a chat room going back to when the chat room was created, which is useful for finding previous discussions and solutions to problems.
However, like logged IRC channels, Gitter has a tradeoff of greater convenience against lower privacy relative to unlogged IRC channels: messages in a permanently logged chatroom are by definition not ephemeral and may cause embarrassment for users who later regret making ill-considered offhand comments in a chatroom.
Gitter was created by some developers who were initially trying to create a generic web-based chat product, but then wrote extra code to hook their chat application up to GitHub to meet their own needs, and realised that they could turn the combined product into a viable specialist product in its own right.
Gitter came out of beta in 2014. During the beta period, Gitter delivered 1.8 million chat messages.