Adding to sibling… Discord is used in a couple of different ways at present for communities. If you mean voice coms for gaming or otherwise, Mumble should be in your repository. If it’s more of a of a Slack-like business chat, self-hosted Mattermost is actually pretty nice. If it’s just text chat, IRCv3 & XMPP have that covered & scale massively even on a home PC. If it’s voice calls, Jitsi or Jami can work. If you are posting updates or things that should be forum topics, you shouldn’t be using chat anyways where Mastodon, Misskey, Lemmy, & other Fediverse options or even Atom feeds can suffice. If you want integrated chat, community updates/posts, voice/video calls (unsure if conference calls are support) Movim is a good option--and if you don’t mind the rough UI edges, Libervia can do similar but also integrates a calendar for events. Bear in mind as well that a lot of these technologies can be bridged between one another to avoid some of the lock-in, but I would hesitate to force everyone’s chat to be piped & logged thru Discord’s servers. It’s also not bad to say “we use these 2 services” rather than requiring a kitchen sink communications application.