Replace-Xyour much needed alternatives
Mattermost
FreemiumCOMMUNICATIONSecure, self-hosted Slack alternative for DevOps.
FREEDOM SCORE3.0Partial
×Is it free?
+1.5✓Open source?
+1.5✓Self-hostable?
+1.0✓Data export?
+0.5×Free pricing tier?
+0.5RELEVANCE SCORE5.0Active
✓Actively maintained?
+1.5✓Large community?
+1.5✓Has public API?
+1.0✓Commit < 3 months?
+0.5✓Stars > 20k?
+0.5About Mattermost
Highly secure messaging platform built on Go. Perfect for developers teams that require internal chat pipelines.
WHAT IT DOES WELL
- +Excellent secure SOC2 and HIPAA compilations
- +Extensive webhook controls and slash integrations
HONEST PROBLEMS
- ✗Strict paid core constraints limit larger group setups
SELF-HOSTABILITY PROFILE
DifficultyMEDIUM
License typeAGPL-3.0
💡 "First tier corporate Slack replacement."
PROJECT METRICS
Repositorygithub.com/mattermost/mattermost
LicenseAGPL-3.0
GitHub Stars⭐ 28,900
Last CommitMay 30, 2026
Last VerifiedVerified May 2026