Mattermost

Featured

Secure, self-hosted team messaging platform as an alternative to Slack

MITSelf-hostableGoTypeScriptReactCommunication

chatmessagingteam-communicationdevops

Website GitHub Docs

35.6k

Stars

8.4k

Forks

389

Contributors

Mar 2026

Last Commit

Project Health

92/ 100

Excellent

Deploy Options

Replaces These Proprietary Tools

Mattermost can be used as an alternative to these commercial products.

Business messaging and team communication platform