"Windows RT is an edition of Windows 8 designed for mobile devices that use 32-bit ARM architecture (ARMv7). Microsoft intended for devices with Windows RT to take advantage of the architecture's power efficiency to allow for longer battery life, to use system-on-chip (SoC) designs to allow for thinner devices, and to provide a "reliable" experience over time." (source: wikipedia)

"Due to the different architecture of ARM-based devices compared to x86 devices, Windows RT has software compatibility limitations. Although the operating system still provides the traditional Windows desktop environment alongside Windows 8's touch-oriented user interface, the only desktop applications officially supported by Windows RT are those that come with the operating system itself; such as File Explorer, Internet Explorer, and Office RT. .... Developers cannot port desktop applications to run on Windows RT, since Microsoft developers felt that they would not be properly optimized for the platform." (source: wikipedia)

With the release of Visual Studio 2013, Microsoft has enabled developers to easily port desktop applications to the Windows RT platform. However, the signing restrictions on the platform do not allow developers to distribute or use these ported applications.

We are petitioning for Microsoft to provide a mechanism to enable the execution of non-Microsoft signed desktop applications. This will open up the platform and enable 3rd party application developers and hobbyists to write Windows desktop software for the platform. Moreover, this will extend the life, value, and usefulness of all existing Windows RT & RT8.1 tablets that have been released in the last 2+ years.