Thanks to some friends at Amazon, I was fortunate enough to get hold of a Kindle Fire HDX the minute they hit retail. Naturally, the first thing I did was pop open the Silk browser and, hoping against hope, opened a web site with WebGL.
It JUST WORKED. Fast JavaScript; beautiful rendering.
Apple, Google: take notes.
This changes EVERYTHING.
Tony Parisi 
Quick update: the Silk team called me to let me know that they are turning off the WebGL in the browser to od a patch. Eventually it will get turned on again. Understand this is in Silk ONLY; if you are building a Kindle Fire HDX *app* in WebGL it will still work. Stay tuned!
Hey Tony,
I downloaded Chrome, Chrome Beta and Firefox for android and webgl works like a charm on my Kindle Hdx. Chrome is the best(as of now).
Chrome works well on my Samsung SIII also.
Thought you would want to know.
Thanks.
Yeh, what thegenre1 said. It’s working great on my android phone with Chrome for mobile, stable channel. (currently v 32)