Apple today released open-source Darwin code for macOS 10.12 Sierra, 9to5Mac reports. Darwin, for those unfamiliar with it, forms the core set of Unix components upon which macOS, iOS, watchOS and tvOS are based, including drivers and the unencrypted kernel along with its BSD portions.
Apple typically releases Darwin code shortly after major macOS releases, and Sierra is no exception. Anyone interested in the intricacies of Sierra’s inner workings can now grab a copy of Darwin via this direct download link.
At post time, the new files had yet to appear on the web UI at opensource.apple.com.
Apple debuted Darwin as an open-source Unix operating system back in 2000. It’s since updated Darwin on a regular basis as its software platforms have been advancing.
It’s important to note that macOS is not Darwin, or vice-versa. While macOS does run on top of Darwin’s foundation, it adds a bunch of things like Carbon and Cocoa APIs, Quartz Compositor and Aqua that make it usable to end users.
It’s these (closed-source) unique layers on top of Darwin that give macOS all the functionality, like the graphical UI, high-level services, applications and so forth.
In other words, Darwin cannot run any software made for the Mac out of the box.
That didn’t stop enthusiasts from taking the open source Darwin code to create all sorts of forks. For instance, projects such as “Darwin-on-arm” modify the Darwin code to let it run on other computing platforms, like the Raspberry Pi or Beagleboard.
And other Darwin distributions, like OpenDarwin and PureDarwin, include patches and even kernel extensions which Apple’s Darwin code lacks.