Prism provides guidance, via design patterns, to help you build flexible, modular Silverlight and WPF applications. These patterns support unit testing, separation of concerns, loose coupling and the ability to share application logic between Silverlight and WPF applications. Prism includes source code for the library itself, extensive documentation, a sample application that shows how the patterns work together in a real-world application. It also includes a Visual Studio add-in to help you easily share code between WPF and Silverlight. This session provides an overview of Prism, and shows how you can use Prism to design and build composite WPF & Silverlight applications