Windows RT is an edition of Windows 8 operating system designed for mobile devices that use 32-bit ARM architecture. 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 designs to allow for thinner devices, and to provide a "reliable" experience over time. In comparison to other mobile operating systems, Windows RT also supports a relatively large number of existing USB peripherals and accessories, and includes a version of Microsoft Office 2013 optimized for ARM devices as pre-loaded software. However, while Windows RT inherits the appearance and functionality of Windows 8, it contains a number of limitations, which includes only being compatible with software obtained from Windows Store, and lacking certain enterprise-oriented features.