I've never used Mattermost before today. After checking out their site, I can see they are also a for-profit company. What does Mattermost offer that Slack does not, other than a bill lower than $195K/year?

You can deploy it self-hosted without paying any fee, so you control your data much more.

Last time I checked they cripple the self-hosted version, asking to subscribe for enterprise plan here and there. Source: deployed their chat locally a couple of weekends ago. Overall, I liked their Slack clone, they this one was a red flag to me. Now I’m not sure we want to deploy this, but I know very little alternatives. Zulip, but it cripples its self-hosted version too. It allows just 10 mobile users (notifications). Maybe Matrix it is then, but it’s not very suitable for airgapped company-wide deployment.

> Maybe Matrix it is then, but it’s not very suitable for airgapped company-wide deployment

Element is literally built for airgapped company-wide deployments - this is precisely what https://element.io/server-suite is? It was originally built to install onto SIPRnet; it's been airgap-first since day 1.

Hi Matthew, thanks for the clarification. Then, Matrix is the only player who does not cripple self-hosted instances, I assume.

Matrix is the protocol, so doesn’t do implementations (just like w3c doesn’t do web servers any more). But the distribution from Element indeed is self-host first, and doesn’t break stuff if you’re airgapped. The paywall (such as it is) is that features which empower the enterprise over the user are paid, whereas one which empower the end-user are FOSS.

Mattermost is AGPLv3. You can deploy the whole stack and own your data without paying a cent to Mattermost the company.

How are you expecting the devs to get paid with zero incentive for customers to do so?

Mattermost is open-core software: you can self-host and they can't turn you off or raise the price.

What's your case for calling it open-core? The whole thing is AGPLv3, so... I'd call it FOSS with some components optionally being usable under Apache 2 terms

That's how they describe themselves: https://github.com/mattermost/mattermost

> Mattermost is an open core, self-hosted collaboration platform that offers chat, workflow automation, voice calling, screen sharing, and AI integration

Interesting. Notably, they also call themselves "open source" in the "About" of the repository. I'm not aware of any critical extensions which are closed-source. The change you've highlighted was made 4 months ago under a commit that gives no explanation: https://github.com/mattermost/mattermost/pull/31247/files , and the discussion there is private.

Notably, they do have some "source-available" code that goes into the enterprise release, at https://github.com/mattermost/mattermost/tree/master/server/...

This mainly seems to relate to metrics and fuzzy search, though it's possible more will move here in the future (it looks like this is a relatively recent development). Until recently they also had experimental support for Bleve full-text search (now seemingly deprecated), but the elasticsearch enterprise feature seems to be the replacement (otherwise they use postgres's ILIKE for built-in text search)

So, all told, Mattermost was open source, and may be moving to open core. Which means now is probably the best time to create a community-maintained fork. The team edition, and almost all features, are currently still open source.

It sounds like the enterprise release is not open source? When someone above says "The whole thing is AGPLv3," I'm not sure everyone is talking about the same "whole thing"?

I personally see any kind of subscription as a technical debt.

Does give you more things to 'hack' for the club. Not all bad I guess, and saving that amount of money is worth creating some 'new projects'.

Matrix would be a better alternative

mattermost is so so so clunky and uncomfortable, but hey, it's free...

Is it? We've been using it self-hosted for years, together with GitLab. It meets all the needs of a small company, and is very pleasant to work with for devs too (i.e., basic Markdown just works, so you can post anything from code to log snippets in a sensible manner).

Setting up Mattermost was one of the best decisions we've made with regards to our tools.

Funny you would mention GitLab - I find it extremely clunky, especially compared to GitHub. Maybe GitHub is primitive in comparison, but it never makes me hunt for basic functionality and the search just works for about everything.

What about the software nudging you to subscribe to their enterprise plans here and there? Did you turned off this, or just ignore?

I've literally never seen this in my self-hosted Mattermost. Where do you see it?

I afraid I nuked my installation already. There were insignificant features, like for their Playbook (or what the name is), where you are offered some extra feature, that goes with the enterprise plan. If I chose my self-hosted instance for some reason, I don’t really need that advertising in my interface all the time. I can understand the reason it’s there, but I don’t like it still.

Not much of an issue. Did this get more annoying in the newest versions?

First time I tested a self-hosted instance was a couple of weeks back. It was their official testing docker container. So perhaps there are versions without that, I don’t know. I assume you should be able to compile this without them, or at least fork the original project. Hence, I’m asking what’s about those banners in real world scenario.

> mattermost is so so so clunky and uncomfortable

I'm quite sure they are open to pull-requests..