Federated social app: Discord-style servers and chat with ActivityPub.
https://github.com/y4my4my4m/harmony
I don’t remember hearing of it till now, yet it claims a lot of desired features. Github page shows only one contributor, one fork, 44 stars; lot of commits in the last week, oldest 3 years ago; GNU Affero General Public Licence v3.0.
Found via https://chat.btfree.org/@ozoned/3850a821-fc6d-431f-b235-feed68605f6e
https://mony.world/ exists, hosted by us, if you want to play with it. (I wasn’t involved in the setup, so can’t answer much about it)
As someone not fond of Discord, it seems pretty decent and pretty Discord-like.