Tealk

I think my next one will be a https://frame.work There is also an overview of supported systems: https://frame.work/en/en/linux

No the software in this case is a classic forum software and stands alone.

I also like it very much.

I have summarized here what I have found out so far, but is currently only available in German https://handbuch.rollenspiel.monster/lemmy/communication/