Windows RT is an operating system for mobile devices developed by Microsoft, primarily for tablet computers but also for convertibles. It is essentially an edition of Windows 8.x built for the 32-bit ARM architecture (ARMv7). First unveiled as a prototype in January 2011 at Consumer Electronics Show, the Windows 8 RT operating system was officially launched alongside Windows 8 on October 26, 2012, with the release of three Windows RT-based devices, including Microsoft's Surface tablet.