Mattermost is an open source, self-hosted Slack-alternative
It's written in Golang and React and runs as a single Linux binary with MySQL or Postgres. Every month on the 16th a new compiled version is released under an MIT license.
This project hosts plugins built by Mattermost staff and community. They are categorized as follows:
- Production: Certified by the Mattermost team, and tested prior to each Mattermost server release.
- Unofficial: Non-production plugins built by Mattermost staff and community.