Unlike the rest of the internet we see little point in endlessly talking about things that are just rumours and not facts.
However, if there is something behind all this, the impact for Mac developers would be enormous – as numerous sites have been reporting in the past few weeks, Apple may be planning to unify iOS and macOS via their ‘Marzipan’ project as well as move their line of Mac computers from Intel to in-house ARM chips.
While this is all speculation at this point, rumours of Apple moving their Macs to ARM have persisted for many years now and fit well with what Apple actually wants: thin devices with long battery life and a high-profit margin. A switch to in-house ARM chips would totally make sense on this front, enabling Apple to make even higher profits on some even more desirable devices. However, there are downsides. While ARM chips may be able to compete performance wise with the quite slow chips in the Macbook/Macbook Air notebooks, we doubt they could replace high-end iMac chips the chips in a hypothetical ‘Mac Pro’. While Apple could move just some models over to ARM, this would make the transition even more burdensome. The performance problem is made worse with the fact that one would undoubtedly need some kind of x86-emulation to run ‘legacy’ binaries. Apple already switched chip architectures twice, from 68k to PowerPC (mid 90s) and from PowerPC to x86 (late 00s) and this has always been very cumbersome for developers (needing to re-write all their apps) and users (putting up with slow binary-emulation). But in both of these cases, they actually migrated to a much faster platform, which made a clear gain visible to everyone, and made binary-emulation workable. If they now switch to a CPU-architecture that is actually slower, we see little reason to stay on the platform. Interestingly a move to ARM would be much easier if their development environment was based on a JIT, like Microsoft have long propagated with C#. The native-compilation model that served them very well to keep the iPhone ahead of the competition performance-wise, may now be a hindrance.
On the topic of ‘Marzipan’ we are even more sceptical. The good part here would be to finally have some Framework/API news for Mac developers. Cocoa has accumulated a lot of cruft over the decades, and while Apple took the chance to make come improvements on iOS with UIKit, they probably didn’t go far enough and never did make it back to the Mac. The pain is even bigger for Swift developers, the sometimes cumbersome integration with ‘legacy’ ObjC APIs is probably the biggest drawback of using Swift. We’ve been waiting for a ‘revolution’ or at least a larger evolution concerning Cocoa for years, and this ‘Marzipan’ could mean just that. However, the very idea of merging Mobile and Desktop interfaces on any kind of level strikes us as extraordinarily dumb. The futile attempt to merge something which does not belong together has cost Microsoft billions during their Windows 7 / Mobile escapades. The fact that Apple has thus far kept the Mac and iOS separate and each working as it should has been a major selling point versus competing devices that are confused about what they actually are. More concretely, we can’t imagine it being possible to create a GUI framework that actually works great to support both touch-based and mouse-based input as well as screen sizes ranging from 4 to 40 inch.
Disagree? Looking forward to totally rewriting your apps for ARM-based Macs based on a UIKit-gone-fat? Let us hear your thoughts in the comment section!
EDIT: Apr20: There may be hope after all. Indeed, premature rumourization is the root of all evil. But it keeps the internet alive 😉