Apple's strategy has been to more cautiously insert features from its mobile operating system, iOS, into the Mac's. It's also added multi-touch gesture input support that assumes a touchpad for laptops or desktops. The result is ever-closer integration, with a minimum of dislocation to users – but no evolutionary leaps, either.
Microsoft has taken a far more drastic approach. It has designed Windows 8 to actually run on mobile tablets. In contrast, Apple's wildly popular iPad runs its own version of iOS. While many old-timers have railed against the emphasis on touch input, it's easy to see why Microsoft took this approach: The company wants to leverage its massive 80 per cent market share in desktop operating systems, while simultaneously familiarising people with the new tile-based interface (formerly known as "Metro") first used in Windows Phone. But desktop users get benefits from Windows 8, too, including much faster startup times and better boot security.
While Lion and Mountain Lion have been at large in the wild for months, we've also gotten a pretty good look at Windows 8, thanks to three publicly available pre-release versions: Developer Preview, Consumer Preview, and Release Preview. At this point, there's little mystery about Windows 8's final shape when it's finally released on 26 October, and developers and journalists have even already reviewed the RTM – release to manufacturing – version (we posted our first impressions of RTM here).
So how do these two new operating systems stack up against each other? I'll take a look at some key areas with head to head comparisons in this feature. If there are important contrasts you'd like to point out, please do so in the comments section below; this list is by no means exhaustive!
Without further ado, let's begin with:
Windows 8's mobile-like UI
Windows 8's new interface is more influenced by Windows Phone than OS X Mountain Lion is by iOS. Window 8's large, touchable "live tiles" give quick access to and display info from your apps. Swiping gestures actually make a better job of letting you do everything using your thumbs than iOS does – which makes sense, since you mostly hold a tablet from both sides.
The legacy "desktop interface" looks a lot like Windows 7, though the eye candy of the latter's translucent Aero Glass effects has been banished. Also gone is the Start button, replaced by the tiled Start page.
Mountain Lion's mobile-inspired elements
With a couple of important exceptions, most of the traits Mountain Lion has inherited from iOS arrived with Lion or even before. These include the App Store and Launchpad, which duplicates iOS's app icons, even letting you group them just as you would on an iPhone. Unfortunately, most of the Mac users I talk to never use Launchpad, preferring the traditional dock icons.
New for Mountain Lion is iMessage – iOS's messaging service that can take the place of SMS text messaging. It's pretty cool to be able to simulate an SMS text chat with one person on an iPhone and the other at his or her Mac desktop.
Another gift from iOS is the Notification Centre, which acts just like the mobile OS's notifications, which you see when you swipe down from the top of the screen. In Mountain Lion, you can swipe in from the left on a touchpad, and it shows an entry for each new email, message, software update or calendar alert.
With Mountain Lion, iCloud becomes more important for Apple's desktop operating system. When you sign into your Apple account on a Mountain Lion Mac, all your mail settings, contacts, Safari bookmarks, messages, iTunes backups and other features will be synced via iCloud. And when you launch the App Store, all the apps you’ve already purchased are available for downloading and installation.
Mountain Lion also builds cloud-based file storage into TextEdit, Pages, Numbers, and Keynote. Microsoft simply makes SkyDrive available to any app developer, and many Windows 8 apps already take advantage of this.
I covered Microsoft's SkyDrive service extensively in my article on Windows 8 and SkyDrive. Like iCloud, SkyDrive can sync all your devices' settings; in fact, Microsoft likes referring to SkyDrive as a "device cloud." In addition to this function, the service can serve as simple online storage, and actually works with Macs and iOS devices as well as Windows, Android, and Windows Phone. Just as with iCloud, SkyDrive remembers which apps you've purchased and lets you download and install them on another machine.
A big difference between SkyDrive and iCloud is that the former offers web access to any files you've stored on it. But SkyDrive becomes more than just a service for Microsoft products: Any Windows 8 third-party apps can make use of it as well, storing files in the cloud and retrieving them. Another cool capability of SkyDrive is Fetch, which lets you grab a file from a PC running the SkyDrive software even if the desired file hasn't been uploaded to the online storage system.
The Mac App Store
Apple's mobile OS showed the value inherent in the platform maker offering its own app store. The store owner can control which apps are offered, and more importantly, collect a premium from the software maker.
However, the user gets something out of this setup, too: You can install purchased apps on any of your other Macs, and updates are handled uniformly, with notifications when they're available. The Mac App Store launched with about a thousand apps, but some estimate there are now around 10,000.
The Windows Store
Microsoft finally got hip to the app store concept and decided to build it into the upcoming hybrid tablet/desktop OS. In many respects, the Windows Store works nearly identically to Apple's: It lets you install apps you've purchased on multiple machines you sign into, and handles updating in a unified manner. Although the terms for developers are a bit more generous than Apple's.
The Windows Store isn't as rich in browsing options as the Mac App Store, since you have to page through the categories. It’s estimated that the Windows Store will launch with about a thousand apps, and there are millions of legacy Windows apps that will still run on Intel-based Windows 8 machines.
Internet Explorer 10
IE10 comes in two flavours – new and desktop. The new (formerly known as "Metro") IE10 is full screen and touch-friendly, while the desktop IE10 uses an interface identical to its IE9 predecessor. Both guises use the same underlying web page rendering engine, which is faster and more compliant with new standards than IE9.
Internet Explorer 10 not only takes hardware acceleration using a PC's graphics processor up a notch, but implements far more HTML5. These are important factors, since many new Windows 8 apps will use IE as their own rendering engine. Like Apple's Safari, IE10 under Windows 8 will allow the syncing of favourites and history.
One of the major new pieces of Mountain Lion was Safari 6. Notably, the Windows version of Safari hasn't come along for this update, so Apple's browser is starting to look like the Mac and iOS exclusive that IE is on Windows and Windows Phone.
With version 6, Safari has fallen in line with most new browsers' design choice of using a single box for address entry and search. Safari’s Cloud Tab feature shows you the tabs that are open on your other devices, so you can resume browsing after moving from one device to another. Very neat. The updated browser also has a new tab view that lets you swipe through large thumbnails.
Sharing from Mountain Lion
Apps in Mountain Lion get a new Sharing arrow button that lets them post whatever current item you're interacting with directly to email, iMessage, Twitter, Flickr, or Vimeo. Support for the one place we all really want to share digital stuff to, Facebook, will be added this autumn. This sharing tool will not only let you post photos and links, but you'll be able to add comments and location info.
Sharing from Windows 8
Windows 8 has a built in Sharing button that's always available from the "charms" toolbar. You can call this up at any time by moving the mouse to the upper or lower right corner of the screen, or by swiping in from the right on a touchscreen. The Share charm taps into email, SkyDrive, and any social network you've connected to the built-in Windows 8 People app.
Extra goodies in Windows 8
Microsoft has built several useful and fun new-style apps that ship with Windows 8, including Mail, Photos, People, Messaging, Weather, Finance, Calendar, Maps, News, Sports, Music, and Video. Many of these display live updated info on their Start page tiles – something not possible on the Mac OS X desktop or even in iOS. Windows 8's Metro Snap feature lets you get a peek at a second app while running your primary app in full screen. A final new pair of goodies in Windows 8 will be the ability to "Refresh" or "Reset" the system. With the first, you keep all your apps but clean out all the operating system gunk files, and using the second, you get a completely new Windows installation – perfect for gifting an older machine to a relative.
And speaking of older machines, perhaps the biggest "extra" for Windows 8 is that its desktop mode can run every Windows legacy app. Not only has it been updated with a more modern, flat window border look, but Windows Explorer and Task Manager have been updated with new looks and capabilities. Drastically faster startup than previous versions of Windows could also be considered an extra, though it's also become an essential for any platform with mobile aspirations, given the iPad's fast startup.
Extra goodies in Mountain Lion
Mac OS X's AirDrop feature stands out among its extra goodies: It lets you transfer files to any nearby Mac without disks, USB keys, or even a Wi-Fi connection. Other nifty capabilities are Auto Save and Versions, which mean you never have to worry about losing a document because you forgot to hit Save. The problem is that software vendors aside from Apple itself have been slow to implement support for Lion's built-in Versions and AutoSave. Find My Mac does for your laptop what's been possible on the iPhone for years. Long-time goodies for Mac users include Preview and QuickTime, which let you view most of the media and document file types you're likely to download.
New for Mountain Lion is Dictation, which lets you talk whenever you'd normally have to type. This is something that's been in since iOS 5.1, and I find it incredibly useful. Also new is the Game Centre – which has iOS roots as well – and this lets you manage all your gaming apps and activities. It also connects you to a gaming network complete with leaderboards, achievements, in-game chat and notifications. Speaking of notifications, don't forget the goodies coming from iOS mentioned earlier, including the Notification Centre and iMessage.
Touch and gesture support
Both Windows 8 and OS X Mountain Lion have claimed greater multi-touch and gesture support, but Windows 8 will actually support touchscreens, whereas Lion doesn't let you use your screen as an input device, instead relying on touchpads that support multi-touch and gestures. Windows 8 will go as far as including a thumb-able on-screen keyboard for tablets without keyboards. Picture touch and swipe passwords represent another very innovative use of the touch interface in Windows 8.
Mac OS X Lion took the OS's touch and gesture support on touchpads to the next level. For Lion, Apple claims that the touch experience is even more direct and natural, featuring rubber-band scrolling, page and image zoom, and full-screen swiping. You'll be able to call up Mission Control, tap to zoom, and use three-finger swiping to switch between full-screen apps. One slightly odd touch change in Lion, however, is that the scrolling direction has been reversed from the default everybody is already used to. Many users (myself included) immediately switched this back to what they're used to in System Preferences.
Both operating systems have somewhat new twists on installation. Windows 8 will be available as installation software for existing desktops and laptops, but for tablets it will only be available preinstalled. One issue for Macs running an earlier OS version than Snow Leopard is that the only way to get the £14 upgrade to Mountain Lion is through the Mac App Store, so users of versions prior to Snow Leopard will have to go through a separate upgrade process to get that first (costing £26, for a total outlay of £40). Windows 8 upgrades will cost £15 for PCs bought between 2 June and 31 January 2013, and £25 for any Windows user – even XP – from its 26 October release until 31 January.
Switching between apps
In OS X Lion, Apple revamped the Spaces virtual desktop feature, wrapping it into the Mission Control app switcher. But Spaces will likely be more frequently used in its new guise, since you can switch virtual desktops via a simple swipe gesture. Windows 8, too, has switching by swipe, but Microsoft's version is just app switching versus virtual desktop switching. Windows 8 also allows a side panel preview of a second app with Metro Snap.
Both operating systems make heavy use of full screen apps. Windows programs have been able to run in full screen for many years, with a simple tap of the F11 key, but Windows 8 Metro apps will be full-screen by default, and it won't have the standard Windows application menus along the top. It will, unlike iOS or Mountain Lion, let users view a sidebar showing a second app. Mac OS has perpetually displayed its own menu atop the screen, even when an app was running in "full screen." That changed with Lion, which lets any program display on the entire desktop screen.
Windows 8 will run on ARM-based mobile processors as well as Intel and AMD x86 chips. While this may not make Intel too happy, it does fit with Microsoft's strategy of making Windows 8 suitable for both the most powerful desktop and the smallest tablet (not phone, though – not yet). But legacy Desktop Windows apps won't run on the ARM version of Windows (RT) unless they're recompiled. Microsoft has built a Metro version of Office for Windows RT, and Mozilla has announced a Metro version of Firefox.