In an 8,600-word epistle yesterday, Microsoft's top Windows executive pulled aside the curtain on the first version of the company's iconic OS that targets tablets.
Dubbed "Windows on ARM," or WOA for short, the new edition is a cousin, perhaps one or two or even three times removed, of the still-under-construction Windows 8 for traditional PCs.
Steven Sinofsky, the president of Microsoft's Windows and Windows Live division, went into great detail on the underpinnings of WOA, and along the way answered some of the questions that have been burning a hole in analysts' and users' brains for more than a year.
But what did he say, and what does it all mean? To help you better understand what Microsoft's up to, we distill the warrant on WOA to a more digestible format. We're not saying this is the end-all, be-all -- read Sinofsky in the original for that -- but it's a start.
When will WOA-powered tablets go on sale? We don't yet know.... You didn't expect Sinofsky to spill all the beans at once, did you? But he was clear that WOA was on the same release pace, more or less, as Windows 8.
"Our collective goal is for PC makers to ship WOA PCs the same time as new PCs designed for Windows 8 on x86/64," Sinofsky said.
Although Microsoft remains mum on Windows 8's launch date, most analysts expect -- and Windows 7's schedule three years ago hints at -- a release in time for the 2012 holiday season.
Do I get to see WOA before then? Not unless you're a tablet or PC maker, or an important developer.
Around the time Microsoft launches Windows 8 Consumer Preview -- it looks like that will be Feb. 29 -- the company will also distribute "a low volume of test PCs specifically designed for WOA," said Sinofsky. Developers and Microsoft's hardware partners will use these Frankenstein-esque PCs to develop on WOA and create and test hardware that may or may not end up connecting to a WOA-powered device.
No public beta, or as Microsoft calls it, "Consumer Preview," of WOA then? Exactly.
But I'll be able to buy a copy eventually? No, you're thinking of this all wrong.
WOA is, as Sinofsky said, "a new member of the Windows family," but it's not Windows 8. It's entirely new, and because it works only on ARM devices -- the processor architecture that powers most smartphones and tablets -- it will not be sold in the traditional manner you're grown to love or hate. Instead, WOA will be tied to a Microsoft-defined line of ARM tablets or PCs, powered by processors designed by Nvidia, Qualcomm and Texas Instruments.
"Windows on ARM software will not be sold or distributed independent of a new WOA PC, just as you would expect from a consumer electronics device that relies on unique and integrated pairings of hardware and software," said Sinofsky.
In other words, WOA is to Windows as iOS is to Mac OS X: You can't go out a buy a copy of Apple's iOS, now can you?
Sinofsky keeps talking about "ARM PCs." What are those? We noticed that, too. It's almost like he had a hard time writing the word "tablet," which is what's generated the most excitement about WOA, as in, "Whoa, Windows finally on tablets."
Sinofsky used the word "tablet" just three times in his mega-missive, almost universally tying "WOA" and "PC" instead. In fact, he used the two-word combination "WOA PC" a total of 23 times in the blog.
Our guesses are that A) Microsoft doesn't like tablets, B) It hates the phrase "post-PC" that Apple's then-CEO Steve Jobs popularized last year, or C) Microsoft expects OEMs to build a wide range of ARM-powered devices, including tablets, more traditional-looking notebooks and hybrids that combine elements of both.
We pick "C."
What apps will run on WOA? Those built for the "Metro" interface, the tile-based look that Microsoft borrowed from Windows Phone.
Windows 8 will also run Metro apps -- that's one of the big selling points Microsoft has been pitching developers -- but WOA will be almost exclusively a Metro platform.
So, I won't be able to run the applications I'm familiar with on WOA? Not in their current form, no. And on that point, Sinofsky was crystal clear. "WOA does not support running, emulating, or porting existing x86/64 desktop apps," he said.
Developers can create new Metro versions of their current software, of course, and sell it through the Windows Store.
What? Why's that? Although he denied that Microsoft was "starting over" with WOA, that sounds exactly what Microsoft is doing by requiring developers who want to write and sell software for WOA to start from scratch with new Metro apps.
His rationale? "If we enabled the broad porting of existing code, we would fail to deliver on our commitment to longer battery life, predictable performance, and especially a reliable experience over time," Sinofsky said.
That last sounds to us like a knock against desktop Windows, which many have said deteriorates in performance the longer it's used.
But I read that WOA includes a desktop.... What gives? There is a desktop, but it's available only to Microsoft.
The only applications that will run on the WOA desktop -- which will look similar to Windows 8's desktop -- are Microsoft's file manager, Windows Explorer; the desktop edition of its Internet Explorer 10 (IE10); and special designed-for-WOA versions of Word, Excel, PowerPoint and OneNote from the upcoming Office 15 suite.
Microsoft won't allow any other developers' current Windows-compatible software to run on the WOA desktop: It's Microsoft-only turf.
And Microsoft's including those Office applications with WOA? Yes. Although Sinofsky didn't go into much detail about Office on WOA, documents created with the four apps will be compatible with Office on a traditional PC.
The programs are different from the Office 15 applications that will run on Windows 8, however. "These new Office applications...have been significantly architected for both touch and minimized power/resource consumption," said Sinofsky
So, Microsoft is giving away Office with WOA? Hang on a minute.... The company never said that. Sinofsky said the four Office apps for WOA will be "included" with the operating system, but nothing more. (And earlier in his dispatch he put it into context: "Today's blog post is about making WOA, not marketing or selling it."
That leaves lots of wiggle room.
Clearly the code for Word, Excel, PowerPoint and OneNote will be on all WOA devices. But the apps could easily be time-sensitive -- they run for a limited number of days or months, as trial software usually does -- or initially with limited functionality. On the latter, think of Office Starter 2010 , the ad-supported, bare-bones edition bundled on many PCs.
In both cases, Microsoft would pitch users a paid upgrade to the full versions of the applications.
We find it hard to believe that Microsoft plans to simply give away Office with WOA-powered devices, what with the money the Office line brings in. Last quarter, the division responsible for Office accounted for 30% of Microsoft's revenue and 52% of all operating income, which is profit before taxes.
And if Microsoft generates revenue by selling WOA Office licenses to device makers, that's going to be reflected in a higher price for the hardware, putting WOA tablets, for instance, at a disadvantage to those powered by Google's Android or Apple's iOS.
Assuming I bite, how will I update WOA and its apps? Two ways. Apps other than those from Microsoft that run on the WOA desktop will be updated through the Windows Store, the company's app market it intends to launch alongside the Windows 8 Consumer Preview at the end of this month.
WOA itself, as well as necessary drivers and IE10, will be updated via Windows Update, as the OS and drivers are now for Windows itself. The Office apps that run on the WOA desktop will be updated and patched through Microsoft Update, the superset of Windows Update that also provides patches, fixes and feature upgrades for Office on Windows.
Is WOA the official name of the OS? Maybe, maybe not. Sinofsky was coy there, saying, "[This is] what we call, for the purposes of this post, Windows on ARM, or WOA."
In other words, the nameplate may change.
What's been the reaction to WOA so far? Generally positive.
Upbeat comments appended to Sinofsky's blog -- over 170 and counting -- were in the clear majority, with many applauding Microsoft for finally clearing the air and answering some of the most pressing questions, such as whether Office will run on WOA and whether there would be a desktop mode.
Some, however, were clearly angry about the lack of support for traditional Windows apps on WOA. "No non-Metro apps, except for the...Microsoft ones, is a huge betrayal to all loyal Win32 developers," said someone identified as "Sammy" in a comment Thursday. "What are we supposed to do? Just throw everything out and start anew?"
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer , on Google+ or subscribe to Gregg's RSS feed . His e-mail address is email@example.com .
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