Mattermost

Overview

Mattermost began life inside SpinPunch, a San Francisco game studio founded in 2011, where the team built an internal messaging tool to replace the chat app they were using to run the business. Recognizing the tool had value beyond gaming, the company pivoted, open-sourced the project in 2015, and rebranded around it as Mattermost, Inc., led by co-founder and CEO Ian Tien. That pivot happened at the same time Slack was becoming the default team chat tool, and Mattermost positioned itself explicitly as the self-hosted alternative for organizations — governments, banks, and defense contractors among them — that could not or would not put internal communications on a third-party cloud.

Mattermost’s licensing is a precise split rather than a single license: Team Edition is fully free and MIT-licensed, giving anyone the right to run, modify, and redistribute the core chat server and clients. Enterprise Edition is built from the same codebase but adds features like SSO/SAML, compliance exports, and advanced permissions gated behind a paid commercial license that restricts reverse-engineering and tampering with its license-key mechanism; Mattermost also lets Enterprise Edition run in a free, unlicensed mode where it behaves identically to Team Edition. The platform is written in Go and React, deploys as a single binary against PostgreSQL, and has grown into a broader “DevOps collaboration” suite through two companion open source projects it maintains: Playbooks, for structured incident-response and workflow checklists, and Focalboard, a Trello/Asana-style kanban board that ships integrated into the Mattermost server.

Key Features

• Self-hosted by default — Deploys as a single Go binary with PostgreSQL, designed for on-premises or private-cloud installs rather than a hosted-first product
• Channels and teams — Slack-style public/private channels, direct messages, and threaded replies
• Playbooks — Built-in checklists and structured workflows for incident response and repeatable processes
• Focalboard — Integrated kanban board for task and project tracking alongside chat
• Compliance and audit tools — Message export, retention policies, and compliance reporting (Enterprise Edition)
• SSO and advanced auth — SAML, OpenID Connect, and Active Directory/LDAP integration (Enterprise Edition)
• Extensive API and webhooks — Slash commands, incoming/outgoing webhooks, and a plugin framework for custom integrations
• Air-gapped deployments — Supports fully offline, disconnected environments common in government and defense use

Use Cases

• Regulated industries — Government, defense, and financial organizations that require on-premises data residency and audit trails
• DevOps and engineering teams — Incident response coordinated through Playbooks alongside day-to-day channel chat
• Enterprises replacing Slack — Large organizations that want Slack-equivalent chat without per-seat SaaS pricing or data leaving their infrastructure
• Air-gapped or high-security environments — Deployments that cannot rely on any external cloud service for internal communication

Who It’s For

Mattermost is for organizations, particularly larger enterprises and government or regulated-industry teams, that need a self-hosted Slack alternative with enterprise-grade access controls and compliance features. It suits IT and DevOps teams comfortable running their own infrastructure and willing to pay for Enterprise Edition if they need SSO, compliance exports, or advanced permissions — smaller teams that just need free-form group chat without those requirements can run Team Edition at no cost, though the interface and admin tooling lean toward enterprise deployment rather than quick, casual self-hosting.