Marzipan: What you need to now about the rumored new XKit

Apple is reportedly working on a new, cross-platform iOS and macOS development framework... but we likely won't see it until WWDC 2019.

Apple has a problem. The teams working on its apps increasingly have to develop and maintain features across iOS and macOS. Sometimes that causes work to go more slowly than anybody would like. Sometimes it causes a lack of feature parity that nobody likes.

That problem is echoed throughout the third-party developer community as well. It results in fewer Mac apps with fewer features updated less often. Or not at all.

So, what to do? The answer, it seems, may be 'Marzipan'.

April 30, 2018: 'Marzipan' isn't 'Marzipan', but it's coming 2019... as part of a new UI

John Gruber, writing for Daring Fireball:

There is indeed an active cross-platform UI project at Apple for iOS and MacOS. It may have been codenamed "Marzipan" at one point, but if so only in its earliest days.

I just assumed Marzipan was the name for one of the candidates for this project, but that Apple was going ahead with a different candidate. Apple often weighs different approaches, like using AppKit or WebKit for iOS before coming up with UIKit, or other languages or storage technologies before going all-in on Swift or APFS.

I don't have extensive details, but basically it sounds like a declarative control API.

It could be part of a bigger project that, to borrow John's HTML analogy, brings a little CSS to the table?

It's a 2019 thing, for MacOS 10.15 and iOS 13.1 I would set your expectations accordingly for this year's WWDC.

That's also when the new Home screen and interface design are currently scheduled to appear, which John doesn't think is a coincidence. And is probably not a coincidence.

Wait, why would Apple need a cross-platform developer framework?

Currently, iOS apps use the UIKit frameworks and Mac apps use the older App Kit frameworks. Photos, which launched cross-platform, was implemented using the seemingly one-off UXKit for Mac, and wasn't exactly an ideal execution.

Other companies were using web apps, Electron (Chrome packaged web apps), or progressive web apps to deploy cross-platform. But, like the Java and AIR apps before them, the ease they offered developers was paid for by users who had to put up with a worse experience.

So, something that let iOS developers take their apps to the Mac, with robust Mac user interface support, seemed like the best solution. A new XKit that superseded UIKit and AppKit on both platforms.

It's such an obvious need, it came up in an early episode of my VECTOR podcast with Gui Rambo. We discussed the possibility of Apple making it easier for iOS developers to deploy apps on the Mac. Not just inside the company, but for everyone.

Just look at the incredibly popular iMessage and Safari, and the incredibly useful Notes and Maps. The ones with the most features have the least parity.

How do we know Apple is really working on something like this?

Nothing really exists until Apple announces it. But, a few days later, Mark Gurman dropped this on Bloomberg:

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, according to people familiar with the matter.

Apple currently plans to begin rolling out the change as part of next fall's major iOS and macOS updates, said the people, who requested anonymity to discuss an internal matter. The secret project, codenamed "Marzipan," is one of the tentpole additions for next year's Apple software road map. Theoretically, the plan could be announced as early as the summer at the company's annual developers conference if the late 2018 release plan remains on track. Apple's plans are still fluid, the people said, so the implementation could change or the project could still be canceled.

I promptly asked Gui Rambo to come back, and we chatted about the idea some more:

What does Marzipan mean for iOS and the Mac?

That's a complicated question, and triggers a lot of fears and uncertainties about how Apple sees the future of the Mac. To try and get a balanced view, I also asked Christina Warren, formerly of Mashable and Gizmodo, currently at Microsoft (which has been working on Universal Windows Apps), John Gruber of Daring Fireball, Loren Brichter, formerly of Tweetie (who made his own cross-platform framework, TWUI), Craig Hockenberry of Twitterrific (which once used a custom cross-platform framework, Chameleon), Ben Sandofsky of Halide, and Greg Pierce of Drafts, what they thought:

Read the transcript

Opinions ranged for Marzipan being something Apple absolutely had to do, both for itself and for the developer community, to concerns over how it would be implemented and whether it would really benefit the Mac or just lead to the further atrophy of the platform.

When could Apple release Marzipan?

For developers, as soon as WWDC 2018 this June. For users, as soon as iOS 12 and macOS 10.14 go live sometime in September. (Though users would only the see the resulting Mac apps, not the frameworks that went into them.)

Will Marzipan really happen, and will it really help?

I'm an optimist, though. iOS is one of the biggest platforms in the world and offers the best app experiences in the world. The Mac, while retaining higher value for apps, doesn't enjoy anywhere nearly as much support.

The worst case senario is a bunch of lazy Mac ports that look like iPad apps and don't work the way you'd expect them to. Like Photos for Mac, but even worse. The best case is fast, native Mac apps we wouldn't have gotten otherwise. Akin to the new versions of iWork apps.

Apple needs to make things better for its own engineering teams, so whatever solution it comes up with has to satisfy internal engineers working on the most-used apps on the platform.

And that's good news for all developers.