You misread my post - or I was just not clear enough.
I KNOW that they use XMPP. That's why I listed them. But both don't (as far as I know) support the multi user chat extension, the whole point of my answer.
What I wanted to say was this: I don't use the MUC in XMPP (a lot) instead of IRC, because it's just not used anywhere. Google, Facebook, could hopefully "just" add it to their existing chat infrastructure.
I KNOW that they use XMPP. That's why I listed them. But both don't (as far as I know) support the multi user chat extension, the whole point of my answer.
What I wanted to say was this: I don't use the MUC in XMPP (a lot) instead of IRC, because it's just not used anywhere. Google, Facebook, could hopefully "just" add it to their existing chat infrastructure.
Better?