[mos_basik]

>most of these Slack-like services have no ignore feature/minimal moderation tools

This is what pushed me away from using Slack with a group of gamers I admin for. I can understand Slack's desire to stick to the workplace and how that leads to "if you need to /ignore a co-worker your company has problems implementing /ignore in Slack can't fix." And I can understand Mattermost wanting to become the opensource/on-prem analog of that. But it really falls apart when you try to use that kind of system with users that don't know you, aren't on your payroll or have issues with rules - like open source developers, or gamers.

My group eventually switched to Discord for, among other things, its amazing ACL-style permissions system, frictionless inviting and unlimited history (iirc, getting history with the first tier of paid Slack would have cost us ~11k USD/year?). It's not perfect - I really hope their bot API gets some love, and of course the ability to host your own server would be nice (though I understand some of the catch-22's there) - but I like it a LOT and I keep encountering new groups of people with Discord servers where I can just idle using one client. This is MUCH more IRC-like experience than I ever got with Slack (for instance, switching between or getting/setting notification alert levels on several different servers is much more ergonomic on Discord than on Slack).

I've not used Gitter a whole lot - just a couple of times when I had a question for some project that had one - but my impression is that it leans more towards "chat with strangers about $topic" (like Discord) and less towards "chat with colleagues about work" (like Slack). In that respect, I'd lay a small amount of money that Gitter does have an /ignore command, among other tools that you miss from IRC.