GNU/consensus/WebRTC
From LibrePlanet
WebRTC
Web Real Time Communication implements browser-to-browser audio and video conferencing, and realtime communication over the Web.
Chris Balls created a proof-of-concept of using out-of-band, manual "peer discovery" to avoid disclosing IP address of the peers to a third party: https://github.com/cjb/serverless-webrtc/