The Yahoo! User Interface Library (YUI) is an open-source JavaScript library for building richly interactive web applications using techniques such as Ajax, DHTML and DOM scripting. YUI includes several core CSS resources. It is available under a BSD License. Development on YUI began in 2005 and Yahoo! properties such as My Yahoo! and the Yahoo! front page began using YUI in the summer of that year. In February 2006 YUI was released for public use under BSD. It is actively developed by a core team of Yahoo! engineers.

The YUI Library project at Yahoo! was founded by Thomas Sha and sponsored internally by Yahoo! co-founder Jerry Yang; its principal architects have been Sha, Adam Moore, and Matt Sweeney. The library''s developers maintain the YUIBlog; the YUI community discusses the library and implementations in its community forum.

Also associated with the YUI Library, the YUI Theater, founded and managed by Eric Miraglia, provides worldwide access to more than 50 talks by notable speakers on JavaScript and web development.


The YUI Library is fully documented on its website; detailed API documentation accompanies the library download. It has six types of components: YUI core, utilities, UI controls, CSS components, developer tools, and build tools.

Source: Wikipedia