Q: Since Windows RT does have a desktop, can I can write my own ARM-compiled Windows RT apps for the desktop?

A: Although Windows RT does have a desktop environment, this is only for specific Microsoft created and signed applications such as Explorer, Internet Explorer, and Office 2013 for RT.

Windows RT desktop will run only ARM applications that have been signed by Microsoft so there is no way to run other applications written by anyone else on the Windows RT desktop. To create Windows RT applications, the application should be written using the Windows 8 store format, formally known as "Metro."

To learn more about the formerly-named "Metro" apps and Windows 8, see "Windows 8, Metro, and Mobile Apps." You might also be interested in "How to Use Windows 8 Live Tiles in an Application."