Ah, I didn’t know that membership in MUC was persistent in XMPP! Reading the XEP I got the idea that presence (definitely transient) and membership were the same thing in the scope of MUC.

Given those two things, it seems like MUC really does support a Slack-like experience these days. That’s great – it definitely didn’t when I last used XMPP extensively!

(Rest in peace, Google Talk XMPP federation – for a while, I could talk to all my friends on Jabber between that and MSN/ICQ bridges.)