I fall back on raw JavaScript DOM manipulation for performance-critical stuff, which is a decent-sized chunk when you're doing arcade games in JavaScript. You can get decent results, but I wouldn't recommend it unless you really are performance-constrained. You end up spending a lot more time than you'd like on browser-specific bugs. If you're just trying to put up a UI to respond to your user's clicks, you're much better off with a lightweight X-platform library like JQuery or Base2.