Why iOS and Mac OS X Won’t Ever Merge, But Can Still Learn From Each Other [Opinion]



It is a popularly held belief that one day Mac OS X and iOS are destined to merge into one OS to rule them all. When Apple announced last October that Lion, the next major update of Mac OS X would feature some of the best ideas from iOS, it only added to the convergence speculation.

But are Apple’s two operating systems really destined to converge? After all, they both seem to be doing very well by themselves. The Mac may benefit from some iOS features, but it’s hardly struggling on its own. Mac sales are stronger than ever. So what exactly would the advantages be?

At CES in January, Microsoft’s CEO Steve Ballmer appeared to have an answer. He proudly announced that the next version of Windows would not only run on PCs, but also on tablets and mobile phones running on the same ARM chip architecture that powers iPhones and Android phones. Ballmer appeared to pour scorn on Apple’s dual operating system strategy, arguing that “Increasingly customers expect the full range of capabilities from every device they use.”

I find this vision of a fully functioning desktop version of Windows running on every device a little problematic. No one is seriously going to plug a mouse into their mobile phone and start editing Excel spreadsheets. Mobile phones are so much smaller than PCs, they require special, simplified interfaces – inevitably with less capabilities than PCs. Even if Windows runs on every device, its user interface will still need to adapt accordingly.

So how does this latest Windows announcement compare to Apple’s strategy? Currently, Microsoft has two Windows platforms. One, a descendent of Windows NT, for PCs, and the other, based on Windows CE, for smaller devices. The next version of Windows should unite these into a single, NT-based system. In contrast, both of Apple’s OSs are already built on the same underlying technologies. They share the same OS X kernel and the iOS’s Cocoa Touch framework is derived from the Mac’s Cocoa framework. In other words, by moving onto ARM chips, Windows is simply catching up to where Apple was four years ago when they launched the first iPhone.

But if Macs and iPhones already arguably run on the same OS, where does this leave speculation about iOS and Mac OS X merging? To address this question, we need to focus on their differences, rather than their similarities. There are essentially two key differences between Mac OS and iOS:

  • User interface: iOS is based on touch-screen while Mac OS X is based upon point-and-click mouse/trackpad
  • CPU architecture: iOS is based on ARM, while Mac OS X is based on Intel

If iOS and Mac OS are to merge, these differences would need to be reconciled. But is this possible? Let’s take each in turn.

User interface

It’s hard to see how or indeed why the user interfaces would ever merge. Touch-screen requires an entirely different UI to point-and-click. The iPad interface is arguably about as similar to the Mac interface as it is going to get. These are two irreconcilable paradigms in computer interaction. Which is better depends on the form factor of the device you are using, and the task that you are performing.

CPU architecture

Intel’s CPUs are expensive, big, hot and power-hungry, whereas ARM-based chips, like Apple’s A4, are cheaper, smaller, cooler and with lower power demands. iPhone and iPads are not going to be migrating to Intel any time soon. But the possibility for Macs running on A4 chips is certainly intriguing. Imagine an even thinner, lighter MacBook Air, with a longer battery life or a Mac mini that is the same size and price as the new Apple TV.

Apple has been quite promiscuous with CPU architectures in the past. We’ve already witnessed two major transitions for the Mac. First from 68k to PowerPC. Then from PowerPC to Intel. That these transitions were so seamless is arguably one of Apple’s greatest technical achievements to date. While developers may have grumbled about having to port their apps to the new architecture, for the most part they did rather well out of it, since it gave the likes of Adobe a great rational for charging their customers hefty upgrade fees.

Of course, Photoshop, Final Cut Pro and Logic users are hardly going to be switching to ARM-based Macs any time soon. ARM is just not powerful enough for pro applications. But for most of us, the advantages in price, size and battery life would certainly make them an attractive option. ARM-based Macs also present the intriguing possibility of dual-mode devices, that could switch between touch-screen and point-and-click input modes. For example, an iMac that unplugs to become a giant tablet, or a MacBook Air that flips over to become an iPad. Both Mac and iOS apps could run on such a device without needing to be ported.

When some commentators predict that Mac OS X and iOS will merge, they describe a hybrid user interface, based upon touch, but with Mac point-and-click features as well. To me, this seems unlikely. If Apple had believed that the Mac UI could be adapted for tablets, wouldn’t they have based the iPad on it, rather than iOS in the first place? But dual-mode devices that can switch between touch-screen and point-and-click modes, supporting both iOS and Mac software certainly present interesting possibilities. And cheaper, smaller Macs based upon A4 chips have the potential to make the Mac platform more popular than ever.