Microsoft has begun releasing more details about Windows on ARM devices. Microsoft executive Steven Sinofsky posted Thursday on the company's Developer Network blog a long description of the "reimagined" Windows on ARM, or WOA, as he called it.
WOA, he wrote, is a new category of the Windows operating system, like Windows Server, Windows Phone, and Windows Embedded. It will be available for ARM-based products, including tablets, smartphones, e-readers and embedded devices.
What Is ARM?
For those unfamiliar with ARM, it refers to devices that use technology from ARM Holdings PLC, a company based in the United Kingdom, that develops intellectual property (IP) for semiconductors. Rather than manufacturing actual semiconductor chips, ARM develops the technology and then licenses its intellectual property to partner companies that produce the semiconductors, chips, and devices.
These partners utilize ARM technology to produce system-on-chip designs, paying ARM a license fee for the original IP, plus a royalty on every chip or wafer produced.
ARM claims its technology is currently being used in 90% of smartphones, 80% of digital cameras, and 28% of all electronic devices.
No Legacy Apps on WOA
Now, getting back to Microsoft's announcements regarding WOA, or Windows on ARM devices....
Out of the box, Sinofsky said, WOA will feel "just like using Windows 8" on x86/64 devices. Starting and launching apps and using the new Windows Store, for instance, will be the same. The goal is to ship WOA PCs at the same time as Windows 8 for x86/64.
ARM devices will feature a Metro mode, with a tile-based, touch-optimized interface, as well as a more traditional Windows desktop mode.
Apps designed for the Metro interface will be supported on both WOA and Windows 8 on x86/64, and WOA includes support for hardware-accelerated HTML5. WOA will offer desktop versions of the key apps in the new Office 15 -- Word, Excel, PowerPoint, and OneNote.
Legacy Windows apps will run under Windows 8 on PCs, but not on WOA devices. This means that developers will not be able to recode their current Windows apps for WOA, under desktop mode.
In discussions with news media, Sinofsky has also noted that the Internet Explorer version for WOA will not support plugins such as Flash, because the industry is trending away from Flash and toward HTML5 technologies on mobile devices. Whether IE on Windows 8 for x86/64 PCs and tablets will support plugins is not yet clear.
'No Single ARM Experience'
Each of the three ARM licensees -- Nvidia, Qualcomm and Texas Instruments -- will also "take a different approach to selecting features, making product trade-offs," Sinofsky wrote, resulting in "no single ARM experience."
One interesting new aspect of WOA is that users will not turn off the PC, and there will be no traditional hibernate and sleep options. Rather, WOA PCs will be designed to always operate in the new Connected Standby power mode.
When the screen goes dark, either through a press of the power button or a timer, the PC goes into a new, very low-power mode in which the battery could last for weeks. Sinofsky said the company was working to provide Connected Standby on x86/64 products as well.
Users of WOA will also have control over what programs have access to background execution, such as always-available email.
When Choice Is a Bad Thing
Al Hilwa, director of application development at IDC, said that "developers are used to complexity," but he wondered if Microsoft was presenting "too many choices." For instance, he noted that Microsoft's "No. 1 goal is Metro-style, touch-based apps," but there's also going to be a second level of touch-enabled apps that work in desktop mode, as well as apps used in traditional ways.
Hilwa also said that Microsoft is being very aggressive in requiring that WOA apps need to be re-architected and newly coded, while existing apps will be able to be recompiled to run on x86/64 devices.
Users will also be faced with many choices, he said, as they walk into a store and find that there are different kinds of apps available on different kinds of Windows machines.