Instead of a Swiss Army Knife OS working on Mac, iPads, and iPhones, Apple just previewed a bridge that’s supposed to let iOS apps cross the OS chasm. One rumor died, replaced by speculation about Apple’s intentions for the iOS apps porting tool.

At Apple’s WWDC18 (its conference for app developers) held last week in San José, CA, Sr VP of Software Engineering Craig Federighi pounded the stage, Finally™ putting an end to the magnetic rumor of a hybrid iOS-macOS operating system:

Having closed one door, Federighi hastened to open a new one. Instead of an OS chimera, Apple’s software chief announced a bridge between the two related but incompatible software worlds. As it turns out, last year’s Marzipan project rumors, which predicated exactly this state of affairs, were accurate:

“Starting as early as next year, software developers will be able to design a single application that works with a touchscreen or mouse and trackpad depending on whether it’s running on the iPhone and iPad operating system or on Mac hardware…Apple is developing the strategy as part of the next major iOS and macOS updates, said [people familiar with the matter]…Codenamed “Marzipan,” the secret project is planned as a multiyear effort that will start rolling out as early as next year…”

In simplified but relevant terms, a foundation of iOS apps, called UIKit, will also appear on macOS:

As a result, in 2019, iOS apps will also run on our Macs. By some measure, there are approximately 2.1M iOS apps in Apple’s App Store. By contrast, macOS apps number in the low thousands — a slightly misleading measure since some Mac apps are available independent of the regulated App Store. But with that caveat, iOS apps certainly outnumber macOS apps by at least an order of magnitude — a ratio that parallels the macOS vs iOS revenue and unit numbers:

The iOS-macOS UIKit bridge will pump new blood into the (relatively) anemic Mac app world. The arrangement will benefit everyone: iOS developers will find new customers on the Mac, customers who pay multiples of $10 vs single digits for iOS apps; Mac users will be given a wider choice of apps; and Apple gets a livelier macOS store.

That’s the idea, anyway. Some nuances may apply.

First, let’s consider the types of iOS apps that are good candidates for migration to the Mac.

Games are often nominated. Since they’re always pushing the limits of the devices that their creations run on, perhaps game developers could benefit from the (slightly) more muscular macOS platform. But many — probably most — iOS games rely on the iPhone’s small screen, touch interaction, and, most important, its mobility: Games pass the time as we’re standing in line at the DMV or waiting for the movie to begin.

What about productivity apps? iOS has always been seen as lacking productivity apps when compared to macOS, so while they do exist on iOS they don’t fill a role that isn’t already well inhabited on a Mac. (We’ll note in passing that Microsoft Office is expected to become available on the newer macOS App Store.)

With the advent of Apple’s Pencil, a number of interesting media creation and editing apps, traditionally an area of Mac strength, found a new home on the iPad. But how do you move them to the Mac? Apple was granted a patent that would allow the Pencil to work with a Mac trackpad a couple years ago, but even so, some skeptics think the trackpad is too small to make it a good option for graphics tablet replacement.

I’ll stop with education apps where the convenient tablet form factor and intuitive touch interface won’t translate well to a Mac.

In each category, we’ll almost certainly see a few felicitous adaptations here and there, but a tidal wave seems unlikely.

At the WWDC, Apple previewed iOS apps that have already been ported to macOS, apps such as News, Stocks, Home, and Voice Memos. But they didn’t provide any information about the amount of work that was required, and there was no discussion of the techniques that are involved in moving from a finger-based interface to a highly precise, pixel-level mouse interaction, among other translation challenges. The tired “It’s A Mere Matter Of Software” is no answer for such delicate interactions with users.

Regarding differing UI models (or paradigms, if you insist), Federighi restated the company’s party line concerning the Mac’s “no-touch screen” article of faith in a Wired interview following the WWDC:

“ […] lifting your arm up to poke a screen is a pretty fatiguing thing to do…”

This is both somewhat true and misleading. Regrettably, the journalist didn’t think of asking Federighi about the legions of productive customers who reach for the iPad screen and pound away on the Smart Keyboard promoted on his employer’s website:

We could turn Federighi’s concern for user fatigue around and wonder if the same Matter Of Software he’s a respected (and well-loved) master of wouldn’t allow for a Mac Magic Trackpad to work on an iPad. The downside is this might end up overcomplicating the (formerly) simple iPad, and add confusion to the already muddled Mac vs. iPad discussion…

In the end, Apple’s UIKit port to macOS raises questions we can’t answer. iOS apps such as News, Stocks, and Home ported to macOS are nice, but, again, I don’t see a stampede of iOS apps crossing the bridge to macOS, not enough to move the Mac volume needle. This leaves us with two possibilities. Either the UIKit move is a titillating but unimportant sideshow, or it’s part of a larger hardware plan for the Mac.

On third thought, one I owe to Steve Troughton-Smith, Fraser Speirs and others on Twitter, there is a simpler explanation. Apple’s UIKit port would yield a smoother path from iPhones to iMacs (or a putative Mac Pro). At one end of the spectrum, multiple 27” monitors, eGPUs (external graphics processors) or multi-terabyte disk drives, at the other iPhones, with iPads in the middle. A single operating system cannot serve both the needs of high-end Mac usage scenarios, and the miniaturization and mobility requirements of iPhones. The macOS UIKit would bridge the gap between two distinct styles of personal computing without bastardizing either. This would allow users to move from an iPad to an iMac without jarring changes in their everyday habits and yet to benefit from the different tasks each device is best suited to. This supports the party line of two distinct (and destined to remain so) personal computing styles.

For Apple, we now get to motive, which is extracting itself from the iPad vs. Mac debate and making the Buy Both pitch much easier.

JLG@mondaynote.com