Dustin Diaz has written an JavaScript library framework that is build on YUI.
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.
Features of DED|Chain:
Built on Yahoo! UI
Easy Chainability
Developer Friendly
Customizable API
Cross browser
