Good point, html5 has some catching up to do here but I think it's possible, at least on JIT'd js environments, to achieve the same performance. Can.js has one

Good point, html5 has some catching up to do here but I think it's possible, at least on JIT'd js environments, to achieve the same performance. Can.js has one of the best performing UI code right now and can do the lazy loading, live binding patterns you're talking about http://canjs.us/ http://canjs.us/