Mattermost

Mattermost isn’t just another chat app—it’s the powerhouse communication platform built for teams that demand security, control, and seamless collaboration. As a fully open-source Slack alternative, Mattermost gives you the reins: self-host on your own infrastructure, enforce strict data governance policies, and rest easy knowing every byte of your conversation stays under your roof.

At its heart, Mattermost provides rich, real-time messaging across one-to-one chats, open channels and private groups. When face-to-face interaction is needed, launch high-definition video conferencing or share screens directly from the conversation window—no external tools required. Organize your team’s to-dos with integrated task boards and Kanban-style “Mattermost Boards,” so tactical planning happens right alongside your discussions.