- Ext JS
- The Yahoo! User Interface Library (YUI)
- SWFObject v2.0 (for embedding Flash content)
- Unobtrusive Flash Objects (UFO) v3.22 (for embedding Flash content)
Here's a quote I like:
If you simply add a class to the body of the document using DOM you can easily offer a chance for a designer to define both the static and dynamic version of the document.