head to head · open source
Mattermost vs pki
Mattermost has 39,101 GitHub stars, 9,006 forks, 1,012 open issues and last shipped today. pki has 509 stars, 162 forks, 46 open issues and last shipped yesterday. Mattermost leads on adoption by 7,582% (39,101 vs 509 stars). Mattermost is written in TypeScript under a custom or non-standard licence; pki is written in Java under GPL-2.0. Mattermost has attracted 23% as many forks as stars, pki 32%. Mattermost was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Mattermost | pki | |
|---|---|---|
| GitHub stars | ★ 39K | ★ 509 |
| License | Custom / other | GPL-2.0 |
| Written in | TypeScript | Java |
| Last push | 2026-09-19 | 2026-09-18 |
| Forks | ⑂ 9.0K | ⑂ 162 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Mattermost if
- You weight community size — 39K stars and counting
- You want the Custom / other license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick pki if
- You want the pki feature set and don't need the biggest community
- You prefer the GPL-2.0 license terms
- Your stack matches Java
- You evaluated both and pki fits your workflow better
About Mattermost
Mattermost is an open core, self hosted collaboration platform for teams that need secure chat, workflow automation, voice calling, screen sharing, and AI integration while keeping the deployment under their own control.
read the full Mattermost overview →
About pki
Dogtag PKI is an enterprise class open source Certificate Authority suite, written in Java and licensed under GPL 2.0, for administrators who need to run their own certificate lifecycle infrastructure rather than buy it as a hosted service.
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Frequently asked questions
Is Mattermost or pki more popular?
Mattermost has 39,101 GitHub stars and pki has 509. Mattermost has the larger community by that measure.
Are Mattermost and pki free?
Both are open source. Mattermost has no licence declared in this registry, and pki is licensed under GPL-2.0. Both are free to self-host.
What is the difference between Mattermost and pki?
Mattermost is written in TypeScript and pki in Java. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Mattermost or pki?
Choose Mattermost if you want the larger community (39,101 stars) or its Custom / other licence terms. Choose pki if its feature set, stack or GPL-2.0 licence fits better. Both are self-hostable.