Release Notes: Important Issues in Windows 8.1
Appendix A: KMS Client Setup Keys
Download Windows 8.1 app samples
Samples are available in C#, C++, and JavaScript and are compatible with the final version of Windows 8.1 and require Visual Studio 2013 or the standalone SDK to compile and run.
Download the WDK 8.1
The Windows Driver Kit (WDK) 8.1 speeds up your development with better provisioning, deployment, and a unified Windows Driver Framework (WDF). Start by downloading either Visual Studio Professional 2013 or Visual Studio Ultimate 2013. Then download WDK 8.1.
Download the Windows Assessment and Deployment Kit (ADK)
The Windows Assessment and Deployment Kit (Windows ADK) is a collection of tools that you can use to customize, assess, and deploy Windows operating systems to new computers. See also Installing the Windows ADK.
Download the Windows 8.1 SDK
The SDK is included with your installation of Visual Studio 2013.