Book excerpt: ASP.NET AJAX server controls can encapsulate even the most powerful AJAX functionality, helping you build more elegant, maintainable, and scalable applications. This is the first comprehensive, code-rich guide to custom ASP.NET AJAX server controls for experienced ASP.NET developers. Unlike other books on ASP.NET AJAX, this book focuses solely on server control development and reflects the significant improvements in ASP.NET 3.5 AJAX and the latest Visual Studio 2008 features for streamlining AJAX development Adam Calderon and Joel Rumerman first review the core Microsoft AJAX Library and JavaScript techniques needed to support a rich client-side experience. Next, they build upon these techniques showing how to create distributable AJAX-enabled controls that include rich browser-independent JavaScript client-side functionality. The authors thoroughly explain both the JavaScript and .NET aspects of control development and how these two distinct environments come together to provide a foundation for building a rich user experience using ASP.NET AJAX. Create object-oriented cross-browser JavaScript that supports .NET style classes, interfaces, inheritance, and method overloading Work with components, behaviors, and controls, and learn how they relate to DOM elements Learn Sys.Application and the part it plays in object creation, initialization, and events in the Microsoft AJAX Library Build Extender and Script controls that provide integrated script generation for their corresponding client-side counterparts Localize ASP.NET AJAX controls including client script Discover ASP.NET AJAX client and server communication architecture and the new support for Windows Communication Foundation (WCF) Understand ASP.NET AJAX Application Services Create custom Application Services Design controls for a partial postback environment Understand the AJAX Control Toolkit architecture and the many features it provides Develop highly interactive controls using the AJAX Control Toolkit Understand AJAX Control Toolkit architecture and build controls that utilize the toolkit