I know its not open source but I've been hearing more and more about Zoom and decided to test it out myself. We had a family social this morning and these are some of my observations:
* Video and audio had no lag (certainly better than I remember from using Skype).
* Everyone got connected without hassles (Linux desktop, Windows laptop, and an iPad).
* The virtual background change is amazing and even worked with mixed colour backgrounds, and even on Linux. Tip: Give it an office background for work meetings like I have attached to this post.
* It recorded (optional) the hour long session and then converted it to MP4 video as well as a separate audio only file. Video was just on 900MB.
* It has tons of optional settings like host can see if attendees do not have Zoom in foreground, can share dual monitor screens, has easy selection for screen sharing and brings it automatically to large view, attendees can annotate shared screens, can share app audio with a screenshare, has technical stats to view, invitees can send 1:1 private messages, can create breakout rooms, can do remote support, shared whiteboard.
* There are lots more granular controls over what attendees can or cannot do and how they can join (via telephone too).