I've set up a self-hosted zulip server for testing. I've never run or used zulip before, so I can't guarantee that it will be stable and I can't guarantee that I won't have to wipe the whole thing (though I'll try hard not to, now that there's a little bit of actual stuff on it).
There is, of course, a nomic on there already. Feel free to join and mess around. Invite link: https://agora-zulip.randomcat.org/join/irl2lks6o7ndf7wgux3uf45j/ -- Jason Cobb Assessor, Rulekeepor, Stonemason