WWDC 2019 had a major impact on the UI toolkit landscape: while the venerable AppKit APIs remained available, Apple removed the old Carbon APIs and introduced 2 brand new frameworks: Mac Catalyst and SwiftUI.
Apple sporadically mentioned some apps built with these new UI toolkits. In this article, I try to bring a better overview of Apple’s use of AppKit, Mac Catalyst and SwiftUI in the different versions of macOS, from macOS Mojave to macOS Ventura.
The charts aren’t a huge surprise to me — there is a lot of AppKit still kicking around in macOS. This transition is going to take a long time, both in the third-party ecosystem and within Apple itself.