This book contains recipes that showcase the common components of YUI, providing suggested examples of use, and a detailed explanation. Except for the first three chapters, which cover the 3 components of YUI that form the foundation for all other components, this book is not meant to be read cover-to-cover. Each recipe is presented as a separate, standalone entity and reading of other prior recipes is not required. Each chapter tackles a particular component or set of related components, introducing the component and explaining how to use it. If you are a web application developer and have some prior experience with or interest in using YUI 2.x to improve the UI of their web applications, then this book is for you. It assumes the reader has prior knowledge of JavaScript, HTML, CSS, and basic understanding of how a website works. This book provides an easy-to-use guide for implementing YUI 2.x components, and does not require an expertise in either JavaScript or YUI.