The YUI team is pleased to announce the public availability of YUI 3.0 Preview Release 1, an early look at what they’re working on for the next generation of the YUI Library. Documentation for YUI 3.0 is on the YUI website; the download is available on the YUI project area on SourceForge;  Keep in mind that this is an early preview, not a production-quality (or even a beta) release. This release is not suitable for production use, but it will give you an idea of what they’re working on, and it should provide a good framework for conversation about the future of the library. They’ve set five design goals for the next generation of the library. What you’ve told us is that YUI 3.0 should be:

• lighter (less K-weight on the wire and on the page for most uses)
• faster (fewer http requests, less code to write and compile, more efficient code)
• more consistent (common naming, event signatures, and widget APIs throughout the library)
• more powerful (do more with less implementation code)
• more securable (safer and easier to expose to multiple developers working in the same environment)

Requirements: -
Demo: http://developer.yahoo.com/yui/3/
License: BSD License