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XAML framework (code name "Jupiter") is a User Interface API that is part of the Windows Runtime - Microsoft's 2011 programming model that forms the backbone of the new Metro-style apps (also known as Immersive) in their new Windows 8 operating system. It is one of the multiple UI APIs in Windows Runtime (the others being HTML5 and DirectX) that enables programming using the Extensible Application Markup Language (XAML). It is the successor to Windows Presentation Foundation (WPF) and Silverlight - similar XAML-based UI frameworks used for desktop applications and portable applications respectively. The XAML framework uses a lot of the same names for its APIs as both of these older technologies - especially Silverlight, but its use is limited to the Windows OS (specifically Windows 8) as with WPF. The major difference is that Silverlight and WPF are largely based on the Common Language Runtime (CLR) and as such require using programming languages such as C# or Visual Basic, while the XAML framework is part of the Windows Runtime, written in native code and also available, and has tools for development, with C++ or C++/CX.
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