JavaScript is the industry standard client-side scripting language that is used in web applications. Professional JavaScript Frameworks: Prototype, YUI, Ext JS, Dojo and MooTools offers an examination of some of the top JavaScript (JS) frameworks that are available, with practical examples and explanations of what each does best. Over the past few years, there's been a small renaissance in JavaScript as a language. A variety of projects have sprung up to build reusable JS libraries and frameworks -- and at this point, a good number of them have matured and shown staying power that they're worth taking a serious look at and relying on in professional projects. JavaScript has grown in popularity in parallel with the Web and today is supported by all major browsers and new web technologies. JavaScript has been extended over time to deliver high-performing and incredibly impressive Web user experiences, using technologies including Adobe Flash, AJAX, and Microsoft Silverlight. As JavaScript is used increasingly for serious development on the Web, the lessons that have been learned and the tools that have been invented along the way are being consolidated and shared by developers in the form of libraries and frameworks. However, since JavaScript is such a flexible and dynamic language, each framework can present very different approaches to the problems of web development -- each with its own pros and cons. Coverageof the individual libraries and frameworks includes: Prototype: Extending and Enhancing DOM Elements Prototype: Handling Cross-Browser Events Prototype: Simplifying AJAX and Dynamic Data Prototype: Working with Forms Prototype: Manipulating Common Data Structures and Functions Prototype: Extending Prototype Yahoo! User Interface Library (YUI): Traversing and Manipulating the DOM with YUI YUI: Handling Cross-Browser Events YUI: Using Animation and Drag and Drop YUI: Simplifying AJAX and Dynamic Loading YUI: Building User Interfaces with Widgets Enhancing Development with the YUI Core YUI: Dealing with Data, Tables, and Charts Working with YUI CSS Tools Building and Deploying YUI ExtJS: Architecture and Library Conventions ExtJS: Elements, DomHelper, and Templates ExtJS: Components, Layouts, and Windows ExtJS: Handling Data and Talking with the Server ExtJS: DataViews and Grids ExtJS: Form Controls, Validation Dojo: Enhancing Development with Dojo Core Dojo: Manipulating the DOM Dojo: Handling Events Dojo: Composing Animations Dojo: Working with AJAX and Dynamic Data Dojo: Building User Interfaces with Widgets Building and Deploying Dojo Expanding Dojo Enhancing Development with MooTools MooTools: Manipulating the DOM and Handling Events MooTools: Simplifying AJAX and Handling Dynamic Data MooTools: Building User Interfaces and Using Animation