Here are some public and semi-public stuff I run from my servers. I host my stuff from two servers. One named NL1 in the Netherlands and one named PL1 in Poland. Some require trust to get an account, some are open, and others are on a case-by-case basis.
A privacy-friendly VOIP. No accounts needed, low latency, works even on potato (Polish) connections.
And pretty decent modern IRC bouncer. Only people I know quite a lot and who trust me, and I am them get an account.
A federated chat protocol better then Discord IMO. Accounts available only to trusted friends. Until I get a second domain.
A bridge written in java (Not my software) that links Discord chats to IRC channels — request access if needed. (Supports webhooks)