Mattermost: What parts are actually FOSS?

I want to set up some kind of open-source project management software to replace Asana.

Just to try it out, I installed the TrueNAS SCALE Mattermost “App.” It’s loaded with a bunch of nags to upgrade to get X,Y, and Z features.

The Mattermost website is obviously canted towards getting you to sign up for a paid product, so it doesn’t outright specify if all of the features are available via open source…

Does anybody know what is and isn’t free and open source as it pertains to Mattermost?

Welcome @oguruma ,
I found this


Mattermost Team Edition

 Team Edition is a free-to-use, open source, self-hosted collaboration platform offering all the core productivity benefits of competing SaaS solutions. It deploys as a single Linux binary with MySQL or PostgreSQL under an MIT license.

Are you thinking of using parts of Mattermost in your project?

Regards
Neville

This wouldn’t be part of a project, but rather just a tool I would use as-is.

The problem is that I can’t ascertain what features are part of the “core productivity benefits.”

The problem with the freemium model is that often you’ll need a specific feature that’s only available part of the paid software, and you end up paying more than you would with a closed-source SaaS solution.

If it is like that, I do not think I would use it at all.
There must be open source alternatives?
Most people writing code just use git and Github.