Book excerpt: With Flash Player on approximately 98 percent of computers connected to the Internet and Flash itself evolving from a simple animation tool to a robust rich-client development platform, there's been just one thing missing from Macromedia's product lineup: A way for server-side developers to easily integrate Flash development into their workflows. Enter Macromedia Flex: With it, you can do everything one can do with Flash--on the server using the Flex Presentation Server software and the new XML-based language MXML. This guide shows you how! If you've ever developed dynamic Web applications on J2EE and .NET architectures, or using technologies like JSP and ASP, you should have no problem transferring those skills to develop rich-client solutions with Flex. After introducing readers to rich-client applications, Flex, and its architecture and typical workflow, authors Steven Webster and Alistair McLeod explore the software feature by feature. Throughout, you'll find examples of the rich-client interfaces you can build with Flex as well as strategies for integrating your Flex apps with existing infrastructures.