DED|Chain is free open source software (BSD License) that will allow you to build first class, high-quality websites without the cruft. You get the reliability of Yahoo! UI, and the developer friendliess of jQuery. You also receive the benefits of an easily customizable A.P.I. which puts you in control of how you will work with the library.
With D|C, I wanted to take the jQuery style and philosophy a step further, but build on top of Yahoo! UI. There are of subtle differences in some syntax choices; for instance, every callback in D|C is executed in the scope of the DED bolt (yes, I’m calling them DED bolts). A DED bolt is the outer-most selector from which each chain is derived.
The old demo de jour was an RSS reader, and now it may be a Twitter client.