Comment by samtuke

We've been using Zulip at our startup for 2.5 years now and still generally love it.

We self host and haven't had any issues with that (pretty much zero maintenance so far). The Android app is awesome.

Searching messages sucks, and I don't know if Slack bots and apps are compatible.

Pretty much everything else is great, and we greatly prefer it to Slack and Mattermost (both of which we used before for years).