Some time back, Sam Tuke posted the findings of the FSFE group in Manchester about "the hunt for Skype alternatives".
Sadly, at the time the conclusion was that there were no *real* replacements, as Skype handled some things (specifically lagging, I think, and latency - latency used to be a *huge* problem in SIP telephony) exceedingly well.
Recently, however, I've been using the public Jitsi videobridge https://meet.jit.si almost daily. It doesn't work with Firefox, but it works with Chromium, most of the time nearly as if there was a hole in the screen to the other person. I'm kind of impressed, and I see fewer problems with the sound etc. that I usually do in Skype for GNU/LInux (which I almost never use - I have to use it sometimes to communicate with customers, though).
Does anyone know of any compelling reason NOT to recommend Jitsi Videobridge as a real free alternative to Skype?