Mattermost, Inc. is a Palo Alto-based company founded in 2016 that develops Mattermost, an open-source collaboration and messaging platform. Designed for technical, operational, and security teams, it is particularly suited for high-security environments. The platform originated from a video game company's need for reliable messaging software and has evolved into a commercial enterprise-grade solution with both paid versions and venture capital support.

Mattermost offers a remote-first platform that facilitates team communication across mobile, web, and desktop clients. It emphasizes security, compliance, and self-sovereignty, making it ideal for industries such as technology, public sector, national defense, and financial services. The core platform includes real-time messaging, file sharing, and team collaboration features, along with enterprise extensions for enhanced security and workflow automation. Mattermost supports both self-hosted and cloud-hosted deployment options, catering to large enterprises and governmental organizations that require robust control over their messaging infrastructure.