This is a *minimal* demo of WebRTC video calling between two browsers.
Because the signalling layer isn't standardized, you'll need to run a
small node.js server to pass signalling messages between the two
browsers.  The media connections are point-to-point, though, once the
signalling has happened no server is required.

This demo is based on Silvia Pfeiffer's WebRTC via Web Sockets demo,
and Muaz Khan's WebRTC-Experiment websocket-over-nodejs demo.
Silvia's demo became obsolete (it uses ROAP signalling while JSEP is
now the standard) and Muaz's demo was more complex than I liked which
made it difficult to figure out what the WebRTC API's were doing.
Both of their code was very helpful to me, though!

Silvia's Blog post:
http://blog.gingertech.net/2012/06/04/video-conferencing-in-html5-webrtc-via-web-sockets/

Muaz's WebRTC Experiments web site:
https://www.webrtc-experiment.com/

Muaz's WebSocket over Node.js demo:
https://github.com/muaz-khan/WebRTC-Experiment/tree/master/websocket-over-nodejs

Installation:

Install node.js from http://nodejs.org

Install Node's websocket package:
$ npm install websocket

Install the node-static package to serve static files:
$ npm install node-static

Usage:

Run the Node server:
$ node websocket-server.js

Point two browsers at http://your-server-address:1337/.  You'll be
prompted to allow the use of your camera and microphone.

One of the browsers clicks "Call" and the call should be set up.

To close the call just reload the page.  Like I said: this is a
minimal demo.

Debugging the Node Server:
  install https://github.com/node-inspector/node-inspector
  run the node app in debug mode (will stop at the first line)
  $ node --debug-brk websocket-server.js
  then in another terminal
  $ node node_modules/node-inspector/bin/inspector.js
   - or -
  $ node_modules/.bin/node-inspector
  open chrome to http://127.0.0.1:8080/debug?port=5858
  step once to go to the first line of the program