The Windows Phone SDK 8.0, includes all the software required to get you started building Windows Phone apps. It can be downloaded from the Windows Phone Dev Center site at http://dev.windowsphone.com.
Unlike previous versions of the SDK, the Windows Phone SDK 8.0 requires Windows 8 64-bit (x64).
After you have downloaded and started the setup program, the setup automatically downloads and installs the required components. The SDK supports the development of XAML, XNA, and Direct3D apps. However, development of XNA apps is supported only for Windows Phone 7.1 apps. Although Windows Phone 8 devices can download and use Windows Phone 7.1 apps, those apps are unable to leverage the new features of the Windows ...