The Catalyst project, which leaks and indiscretions had named Marzipan, aims to allow less effort to port an iPad application to macOS (and not the other way around) or to develop an app only once for the two platforms that are macOS and iPadOS.

Historically, the programs of the iPad are based on a base called AppKit, while those of the macOS second ones use the UIKit framework.

Not for all applications

It is necessary to be aware that not all iPad applications – even the good ones in the Apple sense – are called to be ported to macOS. Either because their design is too closely linked to iOS/iPad OS, or because their developer does not see the point.

Other developers, on the other hand, showed more enthusiasm. It is a perfect solution to avoid specific security problems, to offer a fast and focused experience, much more than on the Web.

In the end, beyond the question of ease and technical feasibility, the issue of the relevance of carrying a whole set of applications will arise. A question that proves that the two types of devices are not equal, at least in the perception of the public and developers. It is probably also what Apple will have to fix if it wants to make Catalyst a success.

In three simple steps

The first step is to check a box in Xcode.

The second is both obvious and much more complicated to implement. You need to have “a good iPad application.” Note, iPad, and not iOS or iPhone. It in itself is a reasonable justification for the introduction of the iPadOS name. If the iPhone and iPad both have touch screens, it would be a mistake to put them in the same basket. iPadOS is the new missing link between iOS and macOS.

A “good iPad application” complies with Apple’s technical recommendations and displays the cleanest code possible. It also means that the developer has made sure that his program can adapt to different screen sizes – 7.9, to 12.9 inches. In short, assuming that the developer has done everything at best over the months and updates, step two is a win-win.

Then comes the third step, and that’s where things get potentially complicated. This last step concerns the “finishing touches.” In other words, make sure the iPad interface is ideally suited for Macs.

Other projects, an ambitious goal?

It will be necessary to wait until autumn and the release of macOS Catalina to get an idea. Will the arrival of iPad applications on our Macs produce a wavelet or tidal wave? Apple weighs all its weight to make sure that everything goes well, even if it is evident that this tool is there to serve a transition phase.

The introduction of SwiftUI, a framework that allows developing an application in a very intuitive and straightforward way by automatically generating large parts of the code, is also an effort in this direction. SwiftUI also offers choices of interface and information formatting, which will thus become de facto standards. However, adapting a similar standard to two platforms is the best.

The stakes behind Catalyst are high. Beyond the enhancement of the software offered on Mac, it is difficult not to consider the arrival of Mac under ARM in the more or less long term. Apple is preparing the ground gently, at its own pace, step by step, once again.