It isn’t really Open Source if it can become not Open Source.

(Breathes in…)

Having spent a large part of today wrestling with a selfhosted mattermost upgrade, it would be nice if they spent a bit of time focusing on making this better, like many other things do. Nothing else, at least since we dropped Atlassian selfhosted apps, has been as consistently poor at this.

Changes to supported databases (not once, but twice), forced migrations, breaking change after breaking change (especially of things that could easily be handled automatically but instead block until you’ve found the log error and researched it), and so on. Support, even for commercial customers, is very poor and sometimes extremely rude (at least one senior dev is very opinionated). And things like arbitratrily restricting how many historical messages you can read without a commercial licence shows a deep disrespect for users, plus random feature creep like adding telephony, who actually uses that?

Compare to Teamcity where you click one link in the ui and are pretty confident stuff will work afterwards, and most other selfhosted apps where major distro specific packages are provided, and add a very rapid release cycle, it’s a lot of work to maintain.

Overall, I’m not convinced that Mattermost is a well run project, foss or not. Major changes in direction smack of poor roadmapping and leadership. It would not surprise me at all if the licence issues in the post turned out to be accidental rather than deliberate.

Seriously, if you’re in the market for a chat app - whether it’s free or a thousands-seat enterprise, pick something else. Almost anything else.

From a read of that issue, it looks like it never was.

Eh, that post title is quite sensationalistic.

1. Nothing regarding the license has changed in the last 2 years.
2. It seems like they consider the non-enterprise code to be licensed under the AGPL:

Thank you for the community discussion around this topic. I do recognize that our licensing strategy doesn’t offer the clarity the community would like to see, but at this time we are not entertaining any changes as such.

UPDATE Feb 2, 2026: To be specific, our license is using standard open source licenses, a reciprocal AGPL license and a permissive Apache v2 license for other areas. Both are widely used open source licenses and have multiple interpretations of how they apply, as showcased in this thread.

When we say we don’t “offer the clarity the community would like to see”, that refers specifically to the many statements in this thread where different contributors are confused by other people’s comments and statements.

For LICENCE.txt itself, anyone can read the history file and see we haven’t materially changed it since the start of the project.

If you’re modifying the core source code under the reciprocal license you share those changes back to the open source community. If you’d like to modify the open source code base without sharing back to the community, you can request a commercial license for the code under commercial terms.

Maybe we can hold the pitchforks a while longer, unless they actually make a negative change.

MostlyMatter (FOSS Mattermost fork without user limits). https://framagit.org/framasoft/framateam/mostlymatter?ref=selfh.st

I learned about this today from the self-host newsletter.