Microsoft has just announced its full suite of Windows 8 editions, and the major news is that Windows on ARM processors will be officially called "Windows RT." It'll join Windows 8 and the newly-announced Windows 8 Pro and Windows 8 Enterprise, which add features like virtualization and encryption to Windows 8. As previously rumored, Windows Media Center will be a separate add-on to Windows 8 Pro. The split in names is notable: "Windows 8" is for x86 machines, while Windows RT will signify ARM processors and a distinctly different experience for consumers.

Windows RT is a whole new approach for Microsoft

Specifically, Windows RT will not be sold separately, but only available pre-installed on new machines with ARM processors. That's a major change in the way Microsoft has traditionally sold Windows, and it underscores a more integrated approach to ARM-powered devices like tablets. Windows RT will also include the Office suite as we previously reported, but no other desktop apps can be installed on ARM machines — the focus instead will be on Metro apps built using the new WinRT development environment. Windows RT will also lack the traditional Windows Media Player and most of the enterprise features found in Windows 8 Pro and Enterprise.

It's an interesting move for Microsoft — the company is insistent that "all editions of Windows 8 offer a no-compromise experience," but by segmenting ARM devices off into Windows RT, it's able to dramatically limit the functionality of the desktop and restrict the final feature list. That's a major change in strategy and messaging from the past few months, but we'll have to see if Microsoft's plan is to build Windows RT into something that's more closely like Windows 8 — or something else entirely.