Microsoft has been ridiculously cagey about the discussion of Windows 8 on ARM. At last month’s CES trade show there was a disturbingly low amount of information. Available information about Windows on ARM was in abrupt demonstrations performed by Microsoft spokespeople or behind glass display cases.

Today Steven Sinofsky of Microsoft released quite a bit of information — over 8500 words even if you exclude image captions and section titles — about Windows on ARM (officially named “WOA”). Feel free to read for yourself at MSDN’s blog, or keep on reading for our brief summary.

Actually most of the blog post is about building Windows 8 on ARM.

We reported that Windows on ARM has been classified as stable for approximately two weeks at this point.  Our questions about WOA availability were answered, and more: WOA is intended to be released simultaneously as Windows 8 for x86-64. WOA will also not be available standalone and you must purchase a device with it pre-installed.

From the chipset through the firmware and drivers, the work is optimized to be great for WOA. Partners are working hard on creative industrial designs and form factors that will include more than tablets. These are all under development today.

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The PC will come with the OS preinstalled, and all drivers and supporting software. WOA will not be available as a software-only distribution, so you never have to worry about which DVD to install and if it will work on a particular PC.

Applications written for Windows on ARM can only be distributed through Windows Update or the Windows Store. Being an advocate of the open PC I find this quite unnerving as it quickly creates situations where art becomes at the mercy of the platform owner similar to what is seen on the consoles. That said, it also seems to suggest that Microsoft is not intending WOA to be fill all the roles of a typical PC.

Word, Excel, Powerpoint, and OneNote will be available for WOA as Office 15. The typical file explorer and desktop will also be available for WOA. Mouse and keyboard support is also available for Windows on ARM. These will all be available within Office so the user can control there their files will be stored.

Windows 8 for x86-64 will be released as an open Beta at the end of the month. Microsoft will also release, by invite only, devices for developers. The intent of course is to give developers time to create applications for WOA. You should not expect those devices to be any more than development tools designed to prevent day-one apps from being developed in a single day.