For those interested in Google's implementation: https://code.google.com/p/webrtc/source/browse/#svn%2Ftrunk%...

or browse the code:

    svn checkout http://webrtc.googlecode.com/svn/trunk/ webrtc-read-only

Also Ericsson's code is on github (I couldn't find a direct link from the parent article): https://github.com/EricssonResearch/openwebrtc/