It used to do XMPP federation too; they might still be exposing XMPP C2S but federation is long gone. Fun fact: if you were on a non-Google server talking to s

It used to do XMPP federation too; they might still be exposing XMPP C2S but federation is long gone. Fun fact: if you were on a non-Google server talking to someone on Google Talk and they clicked the button to "upgrade" to Hangouts, on your end they would show up as perpetually "away" and any messages you sent them would be blackholed. Yes, that was as frustrating as it sounds.