Mattermost — Self-hosted, secure open-source collaboration platform for technical and defense teams
Mattermost offers an open-source Slack alternative that can be deployed on-premises or private cloud with strict data sovereignty.
About Mattermost
Mattermost is the secure collaboration platform for mission-critical engineering, financial, and government organizations. Providing self-hosted chat, playbook incident response workflows, and boards, Mattermost guarantees complete infrastructure ownership and air-gapped security.
Key features
- 100% Self-Hosted & Air-Gapped — Deploy on Kubernetes, AWS, Azure, or private on-prem bare metal servers.
- Incident Response Playbooks — Automate DevOps workflows and checklists during production outages.
- Strict Data Sovereignty — Complete compliance with HIPAA, FINRA, GDPR, and FedRAMP standards.
Pricing
Pricing model: Freemium.
- Free Open Source — $0 — Self-hosted deployment, Unlimited users & history, Community plugins, Playbooks
- Professional — 0 / month — SSO SAML / Okta, Office 365 integration, Advanced permissions
- Enterprise — Custom / year — High availability cluster, Compliance exports, eDiscovery
Pros
- Total ownership of company communications with zero third-party cloud exposure
- Built specifically with DevOps incident management playbooks
- Drop-in migration compatibility with Slack exports
Cons
- Requires DevOps knowledge to maintain self-hosted servers and upgrades
- Third-party SaaS app catalog is smaller than Slack
Platforms
Web, Linux, Windows, Mac, iOS, Android
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