YUI 3 — Yahoo! User Interface Library
YUI 3 is Yahoo!'s next-generation JavaScript and CSS library; it powers the new Yahoo! homepage and incorporates what we've learned in five years of dedicated library development. Today, the YUI 3 Core and a full utility set are ready for use. All YUI projects are BSD-licensed and are available for forking and contribution on GitHub.
On This Page
Documentation
Developer Tools
YUI 3 Gallery
Visit the YUI 3 Gallery for more YUI 3-based components contributed by the YUI community.
Core
Utilities
Component Infrastructure
Widgets
Plugins
CSS Resources
The library's developers blog on the YUI Blog and the YUI community exchanges ideas about YUI3 in the YUI 3.x Forum on YUILibrary.com.
Getting Started
- Check out the examples of YUI in action. We recommend starting with the base YUI module and then moving on to Node. Other utilities like IO and Drag and Drop make for good points of exploration.
- Remember that there are full user's guides for each component here on the website — written by the engineers who write YUI, these are your best resources. Also rely on the searchable API documentation when you have questions.
- Start building. Use the YUI 3 Configurator to configure a page for YUI 3 usage or base your exploration off of one of the existing examples.
- Become a member of the YUI community. Contribute to the conversations going on in the YUI 3 community forums.
YUI Theater: Luke Smith — Events Evolved
YUI engineer Luke Smith provides a deep introduction to the YUI 3 event system including its support for DOM events, event delegation, synthetic events, and custom events.
Support & Community
Forums & Blog
YUI 3 discussion forums are hosted on YUILibrary.com.
In addition, please visit the YUIBlog for updates and articles about the YUI Library written by the library's developers.
Filing Bugs & Feature Requests
The YUI Library's public bug tracking and feature request repositories are located on the YUILibrary.com site. Before filing new feature requests or bug reports, please review our reporting guidelines.

