Open source

Mattermost

Channels, threads and file sharing for a team, on a server you own, with no per-seat meter and no ninety-day history cliff.

mattermost/mattermost · ★ 38,721 · last commit 0d ago · MIT · needs 2048 MB RAM · no ARM builds
Mattermost running from the boot-verified compose file
Mattermost, running from the compose file on this page — screenshot from our verified instance, not marketing material.

One tool, 1 subscription

The same server can serve several escape hatches — that's how a $5 VPS beats a $50 SaaS bill.

SlackKINDA
$8.75/mo