Mattermost
Reviews
Big-picture takes: what it's for and whether it delivers. High-engagement videos from YouTube — not sponsored.
Mattermost: Free Open-source Alternative to Slack
Elestio · 33K views
Tutorials
Step-by-step: exactly how to get things done with it.
An Introduction to Mattermost
Mattermost · 169K views
Self-hosting: Mattermost
Underjord · 33K views