TribeMedia/jitsi-videobridge
Jitsi Videobridge is an XMPP server component that allows for multiuser video communication. Unlike the expensive dedicated hardware videobridges, Jitsi Videobridge does not mix the video channels into a composite video stream, but only relays the received video channels to all call participants. Therefore, while it does need to run on a server with good network bandwidth, CPU horsepower is not that critical for performance.