Mattermost

Mattermost is an open-source, self-hosted online chat service with file sharing, search, and integrations. It is designed as an internal chat for organizations and companies, and mostly markets itself as an open-source alternative to Slack and Microsoft Teams.

The project was originally started as a game development tool within SpinPunch, a video game studio based in the United States. After realizing the potential of the communication tool they had built for internal use, the founders pivoted to focus entirely on the platform. Today, the software is developed by Mattermost, Inc., which manages both the open-source community edition and the commercial enterprise versions.

The product is engineered primarily in the United States, utilizing a global network of open-source contributors. As a software-as-a-service (SaaS) and self-hosted solution, it does not have a physical manufacturing location in the traditional sense, but its headquarters and primary development operations are based in Palo Alto, California. Mattermost, Inc. remains the ultimate owner of the brand, backed by various venture capital firms.