Raphaël — Superb Vector Library for JavaScript
Raphaël uses the SVG W3C Recommendation and VML (mostly equivalent Internet Explorer implementation) as a base for creatinggraphics. This means every graphical object you create is also a DOM object, so you can attach JavaScript event handlers or modify them later. Raphaël’s goal is to provide an adapter that will make drawing vectorart (similar to Flash) compatible cross-browser and easy.
Raphaël currently supports Firefox 3.0+, Safari 3.0+, Opera 9.5+ and Internet Explorer 6.0+.
This looks like a very cool library. We plan to put it to good use in some upcoming projects.