Hey there,
I’m on the search for an alternative to Mattermost for a small institution I’m working with. Mattermost was the strongest contender for our needs, yet they changed their policy regarding self-hosted instances. The factor that killed it for us, is the hard cap on 250 registered users, as we potentially might need to commodate more than that.
Rocket.Chat has similar caps.
We found Zulip, and it seems as it might be what we are looking for, but we haven’t tested yet. Nonetheless, I wanted to address this community, as you may have another good idea?
I tried Zulip for a small org. Used their hosted version since it’s quite generous for nonprofits. I personally liked it, but I was very much in the minority. Most of our people didn’t like it. I don’t think anyone articulated very well why they didn’t like it so it’s hard for me to characterize it other than people bitched about the UI a lot. I personally think it works fine, just be ready for some pushback.
We also tried Mattermost, and the uptake seemed a little easier. If you’re used to slack, discord, etc., most of them are pretty easy to transition to, but if you’re dealing with people that never used a real time chat platform, all of them (even slack) are like pushing a rock uphill because people can be impressively resistant to sensible change.