https://github.com/discourse/discourse
Seems to work okay in general. I'm not a big fan of the gamified notification system it seems to have - whenever I sign up for an instance, it'll send me things like "Super reader achievement unlocked! You read 10 threads." or whatever. I suppose it can be turned off since it's OSS.
It is in our plans to eventually rework how this new user education and notification system works, and I suppose eventually with https://id.discourse.com/ the intent would be that your preferences follow you to every Discourse site you sign up for, so you could just set it once.
As an admin, badges can be disabled entirely, or individually.
If you're interested in trying Discourse, our lowest hosting plan is $20/month, or if you want to self-host there have been a bunch of improvements in the setup process recently, see https://meta.discourse.org/t/self-hosting-discourse-just-got...
I just want pagination and to use my stock browser features...
Jokes aside, I've played around with Campfire and it's very, very simple, but pretty nice to use and easy to set up: https://once.com/campfire
There's an actively developed open source server that allows the clients to connect!
https://github.com/mk6i/open-oscar-server
I wish Smarter Child was still around so we could see how LLMs interact with it.
And to be clear, Teamspeak from version 5 on is not teamspeak. It's matrix with a skin. Not that that's terrible, but it's not great for running it on low power/cost VPS like actual teamspeak was.