Similar to others, used it with Jabber, ncurses based clients and such. It was pretty darn great back in the day. It made me believe that Google wanted to do the right thing, even if it screwed up now and then... Ah more fool me on that one to be sure.
Interestingly enough, when Slack still supported IRC that is how I used it, ncurses based IRC client in the console. Then that was put out to pasture as well.
Sadly the only time I see XMPP these days is in the background transport for Chrome Remote Desktop. It's still there, just not being used for "chat" messages.
Ha, sorry I meant IIRC that is a beach in the village of Ness at the butt of Lewis, but it's been over twenty years since I was last there.
https://maps.app.goo.gl/uG5trsb7bov8u6ZP7 I think that's the place?