MacOS versus iOS
No, they’re not combining. They’re porting
The question for many at this year’s WWDC was: is macOS going to merge with iOS? “To briefly address this question. No.” said Apple software chief and spoilsport Craig Federighi at WWDC.
We still can’t rule out the possibility of a secret bunker under Apple Park where a terrifying iPhone/Mac/HomePod is slumbering in a tank of liquid paraffin. But with far more apps available on iOS, it turns out that Apple’s ‘Marzipan’ project is really about making it easier to port them to the Mac.
In Apple’s Xcode, user interfaces of Mac apps are built using AppKit, while iOS front ends use UIKit. This dates back to when the first iPhone’s OS was forked from Mac OS X, but had to cater for the tiny screen and multitouch input. Soon UIKit will be available for macOS, too. Poke-free adaptations Apple still doesn’t see Macs getting touchscreens: “Lifting your arm up to poke a screen is pretty fatiguing,” said Federighi. (Never mind the iPad Pro with a hardware keyboard.) So some interactions will have to be adapted, but UIKit — not an iOS emulator, but a native feature — will simplify conversion. Apple revealed this is how it ported four iOS apps to macOS (see NEW APPLE APPS! on p21), and that it’ll say more about availability to developers at next year’s WWDC.
It’ll also be possible to write apps targeting both platforms. But it’s not clear if UIKit would ever become the preferred basis for Mac app development, and it seems unlikely to sway developers who use third-party frameworks like Electron, which builds apps for multiple platforms using JavaScript, HTML and CSS instead of Xcode’s Objective-C or Swift.