MyFunnyDev

New release contains new selector engine called Sizzle (the fastest css selector out there) and live events (which work similar to the live query plugin).

More details can be found here

Peppy is a small and very fast css3 selector written by James Donaghue. Here is how you can use it:

var selector = "div";
var context = "#elementId";
var q = peppy.query(selector, context);

Nice presentation about JavaScript closures posted by Stuart Langridge