Windows Presentation Foundation (WPF, previously known as “Avalon”) is part of the Microsoft .NET framework used to create rich client user experiences for Windows applications.
It features a diverse set of controls, layout options, 2D & 3D graphics, media & text handling and enables data binding and style-driven templates.
It uses a combination of XAML, an XML-based markup language, and any of the Common Language Runtime languages to define user interface elements. A fundamental aspect of WPF is to separate the user interface definition from the business logic which enables developers and designers to work concurrently on a single project much more easily. WPF also moves UI rendering off to the video hardware through the use of DirectX freeing the CPU to handle more of the logic tasks.