Jitsi is a good one. There is also WebRTC which is what Google Hangouts are, but I heard that the new Firefox now has a client built in. There is also other clients, like chatb out there. I'm not sure how good non-Google Hangouts WebRTC is. -- Svetlana Belkin A.K.A: belkinsa User Wiki page: https://wiki.ubuntu.com/belkinsa