Microsoft announced Monday it will sell three versions of Windows 8 for Intel computers. Two retail editions of Windows 8 will be sold for x86 and x64 PCs. The third edition will be an OEM-only version that's only available for ARM-based PCs and tablets.

The two primary versions of Windows 8 that were built around the x86 and x64 processors have been dubbed Windows 8 and Windows 8 Pro. The number of editions available of Microsoft's new operating system will be exactly half the number of Windows 7 editions that are available, which include Windows 7 Starter, Windows 7 Home Basic, Windows 7 Home Premium, Windows 7 Professional, Windows 7 Enterprise and Windows 7 Ultimate.

Windows 8 will be the default consumer edition of the new operating system and will replace Windows 7 Home Premium. It will also give users the ability to ability to switch between languages on the fly, just as Mac OSX is able to do. The language-switching feature was typically reserved for high-end versions of the Windows operating system, but apparently Microsoft is ready to bite the bullet. The standard version will also include the new tablet-friendly Metro interface and the new Internet Explorer.

Windows 8 Pro will be the enterprise version of the operating system and include all of the same features as the standard version with a few additions: BitLocker encryption and support for Encrypting File System, client Hyper-V virtualization, the ability to boot from a virtual hard disk, Remote Desktop host capabilities among a few other features.

Windows RT (short for Windows Runtime) is the third and final edition, which will be an OEM-only version made available to low-power ARM processors. Microsoft's goal to run Windows on ultra-light power-efficient devices is not unlike Intel's Ultrabook strategy.

Windows RT will be pre-installed on PCs and tablets power by ARM processors and will include touch-optimized versions of the new Microsoft Word, Excel, PowerPoint and OneNote. In terms of development for Windows RT, Microsoft said this: For new apps, the focus for Windows RT is development on the new Windows runtime, or WinRT, which we unveiled in September and forms the foundation of a new generation of cloud-enabled, touch-enabled, web-connected apps of all kinds.