Microsoft’s plan to bring Windows to ARM chips has been a curious endeavor, mainly because the company hasn’t offered many specifics about how the new version of Windows will differ from the traditional x86 and 64-bit versions of the operating system.

That all changed on Thurdsay with a nearly 9 000-word blog post by Microsoft’s Windows unit president, Steven Sinofsky, in which he divulged a slew of details on Windows on ARM (WOA).

The big takeaways are that Microsoft plans to have WOA PCs available when other Windows 8 computers are shipping, and the company will also include desktop versions of optimised Office 15 apps in all WOA devices.

To refresh: Microsoft announced in January 2011 that it would be porting Windows to ARM chips. Doing so would give device makers an alternative to more power-hungry chips from Intel and AMD when developing Windows devices, and it would allow Microsoft to take advantage of the advances in power efficiency being made by mobile ARM chips.

Office-on-Windows-8 — Office 15 on Windows 8

The Office 15 apps, which will include Word, PowerPoint, Excel and OneNote, are among the few desktop apps that WOA will support. The operating system will include the traditional Windows Explorer file manager, Windows Explorer, and other desktop Windows features, but it won’t run traditional x86/64 Windows apps. Metro-style apps available on the Microsoft Store, however, will run across WOA and all other versions of Windows 8.

As you can see from the screenshot (click for a larger version), Office 15 is aiming for a simpler style than previous iterations. There’s more white space than usual for an Office app, and it’s clear that Microsoft is using its Metro design cues wherever it can.

Another interesting aspect of WOA PCs is that you’ll never be able to turn them off. Microsoft is instead relying on a new “Connected Standby” low-power mode that will purportedly last for weeks. “Connected Standby permeates the engineering for WOA PCs from the hardware through [to] the firmware, [operating system], WinRT platform and apps,” Sinofsky writes. Microsoft is also working to bring the low-power mode to other Windows 8 PCs, but you’ll still be able to turn those off completely.

Microsoft says it won’t release Windows on ARM separately, so it will only be something that you can get when purchasing a WOA tablet or PC. The company will also be rolling out test PCs to select developers and hardware partners around the release of the Windows 8 Consumer Preview at the end of this month. — Devindra Hardawar, VentureBeat