The current implementation is of draft-04
It is serial 010 011 cset 6cda09e18094 4fb64ce72dfd on try
source is at
https://tbpl.mozilla.org/?tree=Try&rev=6cda09e180944fb64ce72dfd
Builds for windows, os x, and linux are at
http://ftp.mozilla.org/pub/mozilla.org/firefox/try-builds/mcmanus@ducksong.com-6cda09e180944fb64ce72dfd/
feedback of any sort welcomed to pmcmanus@mozilla.com