I've built a Component-Entity-System library in JavaScript a while back, and the code is quite similar. You can check it out at https://github.com/qiao/ces.js
The demo actually works in all modern browsers that support WebGL. The reason why I only allowed Chrome to visit was that it was the only browser that could run it smoothly.(At least on my machine at the time I developed this demo).
I have just removed the detection. Sorry for the inconvenience and hope you enjoy it.
I've built a Component-Entity-System library in JavaScript a while back, and the code is quite similar. You can check it out at https://github.com/qiao/ces.js