Discourse vs Mattermost
Both Discourse and Mattermost are self-hosted alternatives to Slack.
Side by side
| Field | Discourse | Mattermost |
|---|---|---|
| Description | Advanced forum / community solution based on Ruby and JS. | Platform for secure collaboration across the entire software development lifecycle, can be integrated with Gitlab. |
| GitHub stars | 48,046 | 39,499 |
| License | GPL-2.0 | ⊘ Proprietary |
| Platforms | Docker | Go, Docker, K8S |
| Latest release | _gh-attach-assets, 15 July 2026 | v11.7.15-rc1, 28 October 2026 |
| Repository activity | 2 November 2026 | 2 November 2026 |
| Health | Active | Active |
| Categories | Communication - Social Networks and Forums | Communication - Custom Communication Systems |
| Website | https://www.discourse.org/ | https://mattermost.com/ |
| Source code | https://github.com/discourse/discourse | https://github.com/mattermost/mattermost |
Where the records differ
Computed from the two records above: a line appears only where the dataset states a figure, a date or a set relation, and no line recommends one application over the other.
- Discourse has more GitHub stars in the dataset, 48,046 against 39,499.
- Both repositories last recorded activity on 2 November 2026.
- Mattermost has the newer release on record: v11.7.15-rc1, 28 October 2026, against _gh-attach-assets, 15 July 2026.
- Licenses differ: Discourse is listed under GPL-2.0; Mattermost under ⊘ Proprietary.
- Platforms differ: Discourse lists Docker; Mattermost lists Go, Docker, K8S.
- Discourse is filed under Communication - Social Networks and Forums; Mattermost is filed under Communication - Custom Communication Systems.