What is Mattermost used for?

Mattermost is a self-hosted, open-core collaboration platform combining team chat, automated workflows, voice calls, screen sharing and AI integrations. It is a good fit for secure internal team messaging, incident response coordination and IT service desk workflows.

Is Mattermost open source?

Yes. Mattermost is open source under a custom licence. Its source code is on GitHub at mattermost/mattermost and is written mainly in TypeScript.

Yes. Mattermost is open source, so the software itself is free to use under the terms of its own licence. A managed cloud version is also available.

Can I self-host Mattermost?

Yes. Mattermost can be self-hosted on your own server or infrastructure.

What is Mattermost an alternative to?

Mattermost is an open-source alternative to Slack, Microsoft Teams, Google Chat and Zoho Cliq. Other open-source alternatives to Slack include Rocket.Chat, Element and Zulip.

Is Mattermost actively maintained?

Yes. The most recent commit to Mattermost was on 2 October 2026, and the latest release is v11.11.1, published on 24 September 2026. The project has 39k stars on GitHub.

Mattermost: open-source alternative to Slack

About Mattermost

Mattermost is an open-core collaboration platform you host yourself, covering team chat, workflow automation, voice calls, screen sharing and AI integrations. This repository is the primary source for core development of the platform. The server is built with Go and React, ships as one Linux binary and depends on PostgreSQL. GitHub lists the license as 'Other'.

Each month, on the 16th, a newly compiled release is published under the MIT license. You can deploy Mattermost on-premises or try it in the cloud. The project highlights use cases such as DevSecOps, incident resolution and IT service desk, and it offers native clients for Android, iOS, Windows, macOS and Linux in addition to the web interface.

Installation options include Docker, Ubuntu, a tar archive, Kubernetes, Helm and an Omnibus package. Developers can build integrations through APIs, webhooks, slash commands, Apps and plugins, and the repository links product and developer documentation, security bulletins and contribution guides. It suits engineering, security and operations teams that want controlled, self-managed team messaging.

Key features

Team chat with channels and threads
Built-in workflow automation
Voice calling and screen sharing
Integration with AI tools
Single Linux binary with PostgreSQL
Native mobile and desktop apps
APIs, webhooks, slash commands and plugins

Good fit for

→Secure internal team messaging
→Incident response coordination
→IT service desk workflows

Built with: TypeScript; Go; React Native; React
Tags: team-chat; collaboration; self-hosted; devsecops; messaging; golang; react; open-core

Mattermost: questions and answers

What is Mattermost used for?: Mattermost is a self-hosted, open-core collaboration platform combining team chat, automated workflows, voice calls, screen sharing and AI integrations. It is a good fit for secure internal team messaging, incident response coordination and IT service desk workflows.
Is Mattermost open source?: Yes. Mattermost is open source under a custom licence. Its source code is on GitHub at mattermost/mattermost and is written mainly in TypeScript.
Is Mattermost free?: Yes. Mattermost is open source, so the software itself is free to use under the terms of its own licence. A managed cloud version is also available.
Can I self-host Mattermost?: Yes. Mattermost can be self-hosted on your own server or infrastructure.
What is Mattermost an alternative to?: Mattermost is an open-source alternative to Slack, Microsoft Teams, Google Chat and Zoho Cliq. Other open-source alternatives to Slack include Rocket.Chat, Element and Zulip.
Is Mattermost actively maintained?: Yes. The most recent commit to Mattermost was on 2 October 2026, and the latest release is v11.11.1, published on 24 September 2026. The project has 39k stars on GitHub.