One of the three editions of the forthcoming Windows 8 (along with Windows 8 standard and Windows 8 Pro), Windows RT is a tablet-focused operating system designed to run on mobile devices powered by ARM-based chips. While Windows RT has been developed for use on tablets and similar mobile devices, it isn’t designed for smartphones, which will instead utilize the forthcoming Windows Phone 8 mobile operating system.
The “RT” in Windows RT stands for runtime, and unlike the other two versions of Windows 8, Windows RT (also called WinRT and Windows on ARM) is an OEM-only edition that won’t be available for purchase in stores. In addition to running on ARM-powered tablets, low-cost notebooks and other mobile devices from a variety of OEMs, Windows RT will also power Microsoft’s own tablet device, the Microsoft Surface Tablet.
