Thanks to everyone for an interesting discussion in the comments below. I apologize that many comments were held for moderation. I allow comments, but I trashed a half-dozen or so that consisted of name-calling or that were otherwise unenlightening. Pro tip: if you include the word “fanboy” in anything except an ironic, self-deprecating sense, you won’t get approved.
“As an in-depth engineering dialog, we tend to favor the long form for Building Windows 8 posts.”
– Steven Sinofsky, President, Windows and Windows Live Division, Microsoft
This week’s epic, 8,617-word post, “Building Windows for the ARM processor architecture,” should have answered nearly every question you might have had about how the next edition of Windows will work on special-purpose devices powered by low-power CPUs built using the ARM architecture.
The ARM version will be available only on new hardware specifically designed for it. Initially, these will probably be in the same tablet form factor popularized by the iPad, although there’s no reason they can’t also be available in designs that look like a desktop or notebook PC. You won’t be able to buy Windows on ARM (WOA) and install it yourself, even if you have an ARM-based device that appears to be identical, spec-wise, to a WOA tablet.
The WOA interface is nearly identical to Windows 8 on traditional PCs built using Intel x86/x64 CPUs, with the same Start and search screens. It will run the same Metro style apps as the x86/x64 edition, available through the same store. It will also allow you to access the Windows desktop, with full access to Windows Explorer (for file management), the desktop Internet Explorer, and other “intrinsic Windows features.”
Apple expert John Gruber is puzzled after reading about Windows on ARM:
So maybe I was right that Windows on ARM would go Metro-only — it’s just that they’ve made an exception for a few built-in apps from Microsoft itself. Why include desktop versions of Explorer and IE, though? Why include two different versions of IE if even the desktop version doesn’t allow plugins?
I’ve heard the same question from several colleagues who know Windows well.
The answer is actually pretty simple, if you think about it.
Why Windows Explorer? Because the new Metro style environment doesn’t have a full-strength file manager. As Sinofsky’s post notes:
You can use Windows Explorer, for example, to connect to external storage devices, transfer and manage files from a network share, or use multiple displays, and do all of this with or without an attached keyboard and mouse—your choice. This is all familiar, fast, efficient, and useful.
That capability isn’t available in the Metro environment, as shipped in the Developer Preview, and there’s nothing to suggest that it’s coming in the Consumer Preview. You can search for files and folders from the Metro-style interface, but that environment really isn’t suitable for management tasks like moving and copying large numbers of files.
Windows Explorer is also the host for the full Control Panel. The Metro style Control Panel has a decent subset of options, but it’s not comprehensive. You need the desktop Control Panel to set up parental controls, for example, or to adjust settings for a printer or network adapter.
Why desktop Internet Explorer? This one is more baffling at first. On x86/x64 systems, the most obvious advantage of the desktop browser is that it will run plugins like Flash, whereas the Metro style browser won’t. On WOA, however, Microsoft says third-party plugins won’t be supported. So why include it at all?
Again, the answer boils down to some management tools that aren’t available in the Metro style browser. For example, the only way to adjust security settings or add a Tracking Protection list is using the desktop version of IE. The desktop is also where you’ll find the full set of Internet Options as well as tools for managing Favorites, history, cookies, and so on.
And, of course, if you want to hook up an ARM-based tablet to a keyboard, mouse, and full-screen monitor, you might prefer to view two web pages side by side—something you can only do with the desktop view of Internet Explorer.
The real surprise in this week’s announcement is that WOA-based devices will include four apps from the forthcoming release of Microsoft Office, which is scheduled to ship at the same time as Windows 8:
WOA includes desktop versions of the new Microsoft Word, Excel, PowerPoint, and OneNote. These new Office applications, codenamed “Office 15″, have been significantly architected for both touch and minimized power/resource consumption, while also being fully-featured for consumers and providing complete document compatibility.
These WOA-compatible Office apps are the only desktop apps that will be allowed on WOA-based devices—third-party developers won’t have any way to build desktop apps for this edition of Windows.
Update: Mr. Gruber graciously links to this post and responds: “But why not write a file manager using Metro? I still don’t get it.”
I could just as easily ask, “Why doesn’t the iPad have a file manager?” I mean, OS X has Finder, so why isn’t there an equivalent in iOS? Answer: Because file managers are complex beasties. Most of the operations you would want to perform require multiple windows so you can drag and drop stuff. They also require direct access to the full file system, which Metro apps don’t have, by design.
Building a Metro style Explorer equivalent would be a major undertaking, and it would require a huge amount of development and testing resources. It would be redundant in the x86 version of Windows 8, where the Windows desktop has full functionality. Why spend those resources when you have a perfectly good tool available for porting, one that users won’t need to be trained to use?
There are some file-management functions in Metro apps: pickers for photos, search tools, and the like. But the Metro environment, at least in this first iteration, does not lend itself to the richness Windows users expect from a file manager. That’s the same approach Microsoft has taken to Internet Explorer in Windows 8 and WOA. The Metro style browser is simple, fast, and good for the majority of common tasks. The desktop version is required for some tasks, and power users won’t need to be trained in its use.
Gruber’s question also misses the fact that Explorer is a host for other “intrinsic Windows features,” including the full Control Panel and the common dialog boxes that will be used by the Office 15 desktop apps included in WOA. You need Explorer to host those functions.