Microsoft has today made available developer tools for Windows 10 so developers can start writing universal apps. Sample code and tools are now available on the Windows Insider Program website.
Using the tools, developers can now begin to modify their current apps to work on the Windows 10 Universal platform, meaning their apps will work on Desktop, Laptop, Tablet, Xbox, Embedded and Mobile devices.
To get started, download Visual Studio 2015 STP6 and the SDK tools.
Source: The Next Web