Another demo that caught my eye is Assasins Creed: Pirates Demo made by the IE engineering team, with HTML5, JavaScript, WebGL and more specifically Babylon.js Here is a web page that explains how to start working with Babylon.js and create 3D virtual worlds in a browser.
I played the demo several times in Firefox 34 and I can say it looks fantastic coupled with nice pirate music. There are nine weather conditions between you can choose to play, and each has its own specifics, like day or night, rainy or sunny etc... Use A, D to keys to turn the ship left or right and W, S to speed up or slow down. Use V to switch camera from third person view to first person view and vice versa. Use mouse to rotate the camera around the ship.
Note: To enable and use these new browser technologies you must have IE11 and Windows 7 Service Pack 1 or other advanced browser like Google Chrome, Opera and Firefox. Safari 5.1.7 does not support WebGL.
