Mattermost
Mattermost is an open-source, self-hostable messaging and collaboration platform designed for teams and organizations. It provides real-time chat, file sharing, video conferencing, and integrations with other tools, serving as a secure alternative to cloud-based services like Slack. It is commonly used for internal communication, project coordination, and DevOps workflows.
Developers should learn and use Mattermost when they need a secure, customizable, and self-hosted communication solution, especially in environments with strict data privacy or compliance requirements like healthcare, finance, or government. It is ideal for teams that want full control over their data, need to integrate with on-premises infrastructure, or require extensive customization through plugins and APIs.