Campfire vs Mattermost

Campfire is a group chat tool by 37signals (makers of Basecamp) sold as a one-time purchase under their ONCE brand. It runs on your own server and provides real-time messaging without recurring subscription fees.

Mattermost is open-source, self-hostable team messaging platform designed as a Slack alternative for security-conscious organizations. It provides comprehensive features for team communication workflows. The tool is actively maintained with regular updates and strong community/vendor support.