All the actual animation and stuff is javascript. HTML and CSS just set up the canvas and styling.I'm very impressed, but this video
makes me feel like its complicated just to complete basic tasks. I am very impressed by those capabilities, and it's clever how people make games like that, but the big question is, is it Object Oriented?
Javascript is based off of ECMAScript - as is actionscript. The languages are very, very similar.
Here's a link to a better example of a game with javascript and HTML5 - the original command and conquer.
http://www.ghacks.ne...ml5-javascript/