Why is macOS also known as ‘Darwin’?
It is not. macOS is not Darwin and Darwin is not macOS.
The historical past of macOS is lengthy, convoluted, and sophisticated.
It begins with Steve Jobs (not fully voluntary) “leaving” Apple and founding NeXT. NeXT wished to revolutionize the Private Workstation. They constructed each a robust laptop, the NeXT Laptop (later NeXTstation and NeXTcube), and a strong, fashionable Working System, known as NeXTStep. (Get it? The subsequent step for the subsequent laptop. Actually inventive naming.)
The Working System was based mostly on porting BSD to a Mach microkernel, and including object-oriented system libraries, frameworks, and toolkits (known as “kits”, which you’ll be able to nonetheless see in Apple’s naming in the present day), with an object-oriented GUI framework and desktop, with object-oriented functions, all written in a contemporary object-oriented programming language (Goal-C) because the programs language, on high of the bottom BSD system. The show system was based mostly on PostScript, and there was even an Intel i860 coprocessor working a stripped-down model of the OS, just for Show PostScript processing, plus a robust DSP for video and audio processing.
NeXTStep pioneered many issues we see in fashionable GUI programming. It had one of many first graphical GUI Builders, which nonetheless to today is the way you design GUIs for macOS, iOS, iPadOS, and so on. (Right now, it’s known as the Xcode Interface Builder.) It had the primary ever App Retailer. When Tim Berners-Lee invented the World Large Net, he selected NeXTStep because the OS to put in writing the primary browser for. Many recreation studios used NeXTStep and NeXT workstations for his or her improvement, e.g. id software program for Doom, Doom 2, and Quake. Lotus Improv, nonetheless thought-about by many to be miles forward of Excel even now, was applied on NeXTStep.
Later, NeXT divorced the higher-level frameworks from the underlying OS and made them out there below the title OpenStep for Home windows NT, Solar Solaris, and below the title “OPENSTEP for Mach” nonetheless based mostly on the identical underpinnings as the unique NeXTStep.
At this level, Apple had tried and failed a number of occasions to modernize MacOS, and so they purchased NeXT (thus bringing Steve Jobs again into the corporate) and all of its Mental Property and know-how to develop a successor to MacOS based mostly on OPENSTEP for Mach. They modernized the Mach kernel from 2.5 to three and prolonged it with ideas from the FreeBSD kernel to kind a kernel often called xnu (a reference to the failed nuKernel undertaking at Apple which was to develop a “new kernel”), and the BSD underpinnings from 4.3BSD to 4.4BSD and later FreeBSD.
Most significantly, they prolonged and expanded the OpenStep APIs and constructed new APIs on high. The gathering of these APIs is named “Cocoa”. Additionally they constructed an API known as “Carbon”, which was a detailed, however not an identical re-implementation of a subset of the MacOS API on high of the brand new foundations. (The intention was that whereas it could not be potential to easily re-compile present MacOS functions, it needs to be pretty straightforward to port them to Carbon, after which over time rewrite them in Cocoa.)
The primary prototype of this technique was known as Rhapsody. The complete system wasn’t completed in time, so a subset was launched as MacOS X Server 1.0. And the remaining is historical past: Rhapsody turned MacOS X, then OS X, then macOS, and someplace alongside the best way, iOS was break up off, after which additional divided into iOS, iPadOS, tvOS, and watchOS.
Now, again to Darwin: Darwin is principally the underpinnings of macOS, from the xnu kernel, IOKit, drivers, and so on. as much as the BSD libraries and userland, plus some macOS-specific developments corresponding to mDNSresponder and launchd. It doesn’t, nonetheless, embrace any components of what was once OpenStep, Cocoa, Aqua, Quartz, QuickTime, or any of the opposite higher-level stuff. It does include drivers and filesystems, though I’m not fully positive whether or not APFS is a part of Darwin.
In case you suppose again to the time limit the place NeXT “divorced” the high-level OpenStep from its underpinnings, the low-level components which can be not OpenStep could be those that will later develop into Darwin.
To start with, Apple used to make Darwin out there as a separate OS, together with compiled binaries, installers, ISOs, and so on. that you possibly can set up on Apple {hardware}. Nevertheless, for a few years now, Apple solely gives a supply code dump, each time a brand new launch of macOS comes out. It is not even potential to compile this supply code, as a result of it is dependent upon Apple’s inner construct instruments and construct pipeline. There have been some tasks making an attempt to patch Darwin to compile it with publicly out there instruments, however these tasks have all died from lack of curiosity.
Since the entire belongings you talked about had been born on Unix and use Unix APIs and Unix libraries, they really usually do not even know concerning the “non-Darwin” components of macOS, so it is just logical that they are going to take into account the OS to be “Darwin”. Word that “Darwin” can be what will get returned because the title of the OS if you name the Unix/POSIX int uname(struct utsname *buf) library perform or the uname Unix/POSIX commandline utility.
So, to reply the query you did not ask explicitly however is implicit in your query: why does Node.js return “Darwin” for the title of macOS? As a result of when Node.js asks macOS for its title, that is what macOS tells it its title is!
