At this time the things I am really interested in are inj green and purple. Though not supported yet for Screen Sharing, the API and stream call are available with a plugin.
This will attempt to use STUN over TURN / ICE (TURN-STUN) but for free ;).
List of public stun servers
SIMPLEWEBRTC is a very nice API I found listening to Lisa Larson-Kelley on Pluralsight. Found that the code was in place here:
Open chrome, copy out HTML and JS. Copy JS into a scripts file and reference it.
Change the latest.js to simplewebrtc.com/latest.js
Copy out the HTML and JS, Move JS into another file and reference, then make latest reference site like so:
After that you should be good to go.
Here is a set of 3 instances al connected.