jQuery.spritely is a jQuery plugin created by Artlogic for creating dynamic character and background animation in pure HTML and JavaScript. It's a simple, light-weight plugin with a few simple methods for creating animated sprites such as the birds you see on this page, and dynamic scrolling backgrounds. You can use it on any html web page, and any part of the page can interact with a sprite (click anywhere on this page and wait and you'll see what we mean).

Paper animation kits

AS3 isometric engine