Near the end of yesterday's WWDC keynote, Craig Federighi, Apple's senior vice president of software engineering, acknowledged that people have been asking for a long time whether Apple would ever merge the iPhone and Mac operating systems. His short answer? "No." The word "No" appeared in giant white letters on the colossal screen behind him. Within minutes, screenshots of the "No" had populated Twitter, some with memes attached.

Except, that "No" should have had an asterisk after it, because while Apple still plans to ship two distinct operating systems—one for mobile, one for desktop—the company has been working on bringing iOS apps to Mac hardware. In an exclusive interview with WIRED, Federighi said the frameworks for porting iPhone and iPad apps to the Mac have been in development for two years. He revealed some of the technical details around how this will work, and shared some of the types of iOS apps he believes make sense on the Mac. Federighi was also dismissive of touchscreen laptops—a product category that would seem like a natural addition to Apple's line once laptops begin running touch-first mobile apps.

Double Standard

The point of this is not to create a single unified OS, Federighi said. But the fact that Apple spoke openly about an initiative that could arrive as late as a year from now is a clear nod to how the tech giant perceives the future of apps. It also says something about the health of the Mac's App Store, which has tens of thousands of apps but remains dwarfed by the the mobile App Store, which boasts millions of apps.

Behind the scenes, Apple has been building tools third-party developers can use to port their apps from iOS to MacOS with what Federighi insists will be minimal effort.

At WWDC on Monday, Apple said some of its homegrown iOS apps, including Home, Stocks, News, and Voice Memos, would be available later this year on MacOS Mojave, the next version of MacOS. On the surface, it seems obvious that Apple might make some of its own apps available across different platforms. But behind the scenes, Apple has been building tools third-party developers can eventually use to port their own apps from iOS to MacOS with what Federighi insists will be minimal effort. Apple began this initiative around two years ago, and its own internal software engineers have been beta testing the tools. These four iOS apps for Mac are the products of that testing.

These efforts had been rumored before. Bloomberg reported at the end of last year that Apple was working on some sort of solution to let app makers build a single app that could run across both iOS and MacOS. But there were still questions about how these multi-platform apps would be developed and how certain interactions would work; using an iPhone touchscreen is different from using a mouse on on a Mac, for example.

Native Tongues

At a high level, Federighi described what Apple is doing as bringing an iPhone software framework over to Mac and making it native to Mac, rather than using some type of simulator or emulator. Both iOS and MacOS share a common kernel and have common sets of frameworks for things like graphics, audio, and layout display. But over time, each platform has evolved differently. The biggest and most well-known framework is UIKit, but that was built for iOS way back at the start and wasn't designed to address mouse and keyboard controls. With MacOS Mojave, UIKit will be updated. Just like developers are currently able to target an iPhone or an Apple TV as the device where their app will run, they'll soon be able to target the Mac as well.

Even though the apps are being shared between operating systems, Federighi emphasized that your Mac won't start behaving like an iPhone.

For app makers, some aspects of app porting will be automated and others will require extra coding. Using Xcode, Apple's app-making software that runs on Macs, a developer will be able to indicate they want to write a variant of their iOS app for MacOS. Certain interaction UIs will happen automatically, like turning a long press on iOS into a two-finger click on a Mac. App makers may have to do some extra coding, though, around things like menus and sidebars in apps, such as making a Mac app sidebar translucent or making share buttons a part of the toolbar.