ⓘ Macintosh operating systems


Apple DOS

Apple DOS is the family of disk operating systems for the Apple II series of microcomputers from late 1978 through early 1983. It was superseded by ProDOS in 1983. Apple DOS has three major releases: DOS 3.1, DOS 3.2, and DOS 3.3; each one of these three releases was followed by a second, minor "bug-fix" release, but only in the case of Apple DOS 3.2 did that minor release receive its own version number, Apple DOS 3.2.1. The best-known and most-used version is Apple DOS 3.3 in the 1980 and 1983 releases. Prior to the release of Apple DOS 3.1, Apple users had to rely on audio cassette tapes ...


Mac OS X 10.2

Mac OS X Jaguar is the third major release of Mac OS X, Apples desktop and server operating system. It superseded Mac OS X 10.1 and preceded Mac OS X Panther. The operating system was released on August 23, 2002 either for single-computer installations, and in a" family pack,” which allowed five installations on separate computers in one household. The operating system was generally well received by most Mac users as a large step forward in the areas of stability, general speed enhancements, compatibility with other flavors of Unix and the lineup of both graphical and terminal applications ...


Homebrew (package management software)

Homebrew is a free and open-source software package management system that simplifies the installation of software on Apples macOS operating system and Linux. The name is intended to suggest the idea of building software on the Mac depending on the users taste. Originally written by Max Howell, the package manager has gained popularity in the Ruby on Rails community and earned praise for its extensibility. Homebrew has been recommended for its ease of use as well as its integration into the command line. Homebrew is a non-profit project member of the Software Freedom Conservancy, and is ru ...

Macintosh operating systems

ⓘ Macintosh operating systems

The family of Macintosh operating systems developed by Apple Inc. includes the graphical user interface-based operating systems it has designed for use with its Macintosh series of personal computers since 1984, as well as the related system software it once created for compatible third-party systems.

In 1984, Apple debuted the operating system that is now known as the "Classic" Mac OS with its release of the original Macintosh System Software. The system, rebranded "Mac OS" in 1996, was preinstalled on every Macintosh until 2002 and offered on Macintosh clones for a short time in the 1990s. Noted for its ease of use, it was also criticized for its lack of modern technologies compared to its competitors.

The current Mac operating system is macOS, originally named "Mac OS X" until 2012 and then "OS X" until 2016. Developed between 1997 and 2001 after Apples purchase of NeXT, Mac OS X brought an entirely new architecture based on NeXTSTEP, a Unix system, that eliminated many of the technical challenges that the classic Mac OS faced. The current macOS is preinstalled with every Mac and is updated annually. It is the basis of Apples current system software for its other devices – iOS, iPadOS, watchOS, and tvOS.

Prior to the introduction of Mac OS X, Apple experimented with several other concepts, releasing different products designed to bring the Macintosh interface or applications to Unix-like systems or vice versa, A/UX, MAE, and MkLinux. Apples effort to expand upon and develop a replacement for its classic Mac OS in the 1990s led to a few cancelled projects, code named Star Trek, Taligent, and Copland.

Although they have different architectures, the Macintosh operating systems share a common set of GUI principles, including a menu bar across the top of the screen; the Finder shell, featuring a desktop metaphor that represents files and applications using icons and relates concepts like directories and file deletion to real-world objects like folders and a trash can; and overlapping windows for multitasking.


1. Classic Mac OS

The "classic" Mac OS is the original Macintosh operating system that was introduced in 1984 alongside the first Macintosh and remained in primary use on Macs until the introduction of Mac OS X in 2001.

Apple released the original Macintosh on January 24, 1984; its early system software was partially based on the Lisa OS and the Xerox PARC Alto computer, which former Apple CEO Steve Jobs previewed. It was originally named "System Software", or simply "System"; Apple rebranded it as "Mac OS" in 1996 due in part to its Macintosh clone program that ended a year later.

Classic Mac OS is characterized by its monolithic design. Initial versions of the System Software run one application at a time. System 5 introduced cooperative multitasking. System 7 supports 32-bit memory addressing and virtual memory, allowing larger programs. Later updates to the System 7 enable the transition to the PowerPC architecture. The system was considered user-friendly, but its architectural limitations were critiqued, such as limited memory management, lack of protected memory and access controls, and susceptibility to conflicts among extensions.


1.1. Classic Mac OS Releases

Nine major versions of the classic Mac OS were released. The name "Classic" that now signifies the system as a whole is a reference to a compatibility layer that helped ease the transition to Mac OS X.

  • System Software 5 – released in 1987
  • System 7 / Mac OS 7.6 – released in 1991
  • System Software 2, 3, and 4 – released between 1985 and 1987
  • System Software 6 – released in 1988
  • Macintosh System Software – "System 1", released in 1984
  • Mac OS 8 – released in 1997
  • Mac OS 9 – final major version, released in 1999

2. Mac OS X / OS X / macOS

macOS originally named "Mac OS X" until 2012 and then "OS X" until 2016 is the current Mac operating system that officially succeeded the classic Mac OS in 2001.

Although the system was originally marketed as simply "version 10" of Mac OS, it has a history that is largely independent of the classic Mac OS. It is a Unix-based operating system built on NeXTSTEP and other technology developed at NeXT from the late 1980s until early 1997, when Apple purchased the company and its CEO Steve Jobs returned to Apple. Precursors to the original release of Mac OS X include OpenStep, Apples Rhapsody project, and the Mac OS X Public Beta.

macOS makes use of the BSD codebase and the XNU kernel, and its core set of components is based upon Apples open source Darwin operating system.

macOS is the basis for some of Apples other operating systems, including iPhone OS/iOS, iPadOS, watchOS, and tvOS.


2.1. Mac OS X / OS X / macOS Desktop

The first desktop version of the system was released on March 24, 2001, supporting the Aqua user interface. Since then, several more versions adding newer features and technologies have been released. Since 2011, new releases have been offered on an annual basis.

  • macOS Mojave – version 10.14, released to end users on Monday, September 24, 2018
  • Mac OS X Lion – version 10.7, released to end users on Wednesday, July 20, 2011
  • macOS Catalina – version 10.15, released to end users on Monday, October 7, 2019
  • Mac OS X 10.2 – also marketed as "Jaguar", released to end users on Friday, August 23, 2002
  • OS X Mavericks – version 10.9, released to end users on Tuesday, October 22, 2013
  • OS X Yosemite – version 10.10, released to end users on Thursday, October 16, 2014
  • macOS High Sierra – version 10.13, released to end users on Monday, September 25, 2017
  • Mac OS X Leopard – version 10.5, released to end users on Friday, October 26, 2007
  • OS X El Capitan – version 10.11, released to end users on Wednesday, September 30, 2015
  • Mac OS X Tiger – version 10.4, released to end users on Friday, April 29, 2005
  • OS X Mountain Lion – version 10.8, released to end users on Wednesday, July 25, 2012
  • Mac OS X Panther – version 10.3, released to end users on Friday, October 24, 2003
  • Mac OS X 10.0 – code name "Cheetah", released to end users on Saturday, March 24, 2001
  • macOS Sierra – version 10.12, released to end users on Tuesday, September 20, 2016
  • Mac OS X Snow Leopard – version 10.6, publicly unveiled on Monday, June 8, 2009
  • Mac OS X 10.1 – code name "Puma", released to end users on Tuesday, September 25, 2001


2.2. Mac OS X / OS X / macOS Server

An early server computing version of the system was released in 1999 as a technology preview. It was followed by several more official server-based releases. Server functionality has instead been offered as an add-on for the desktop system since 2011.

  • Mac OS X Server 1.0 – code name "Hera", released in 1999
  • macOS Server – several releases since 2001

3.1. Other projects A/ROSE

The Apple Real-time Operating System Environment A/ROSE was a small embedded operating system which ran on the Macintosh Coprocessor Platform, an expansion card for the Macintosh. The idea was to offer a single "overdesigned" hardware platform on which third-party vendors could build practically any product, reducing the otherwise heavy workload of developing a NuBus-based expansion card. The first version of the system was ready for use in February 1988.


3.2. Other projects A/UX

In 1988, Apple released its first UNIX-based OS, A/UX, which was a UNIX operating system with the Mac OS look and feel. It was not very competitive for its time, due in part to the crowded UNIX market and Macintosh hardware lacking high-end design features present on workstation-class computers. A/UX had most of its success in sales to the U.S. government, where POSIX compliance was a requirement that Mac OS could not meet.


3.3. Other projects MAE

The Macintosh Application Environment MAE was a software package introduced by Apple in 1994 that allowed users of certain Unix-based computer workstations to run Apple Macintosh application software. MAE used the X Window System to emulate a Macintosh Finder-style graphical user interface. The last version, MAE 3.0, was compatible with System 7.5.3. MAE was available for Sun Microsystems SPARCstation and Hewlett-Packard systems. It was discontinued on May 14, 1998.


3.4. Other projects MkLinux

Announced at the 1996 Worldwide Developers Conference WWDC, MkLinux is an open source operating system that was started by the OSF Research Institute and Apple in February 1996 to port Linux to the PowerPC platform, and thus Macintosh computers. In mid 1998, the community-led MkLinux Developers Association took over development of the operating system. MkLinux is short for "Microkernel Linux," which refers to the projects adaptation of the Linux kernel to run as a server hosted atop the Mach microkernel. MkLinux is based on version 3.0 of Mach.


3.5. Other projects Star Trek

Star Trek as in "to boldly go where no Mac has gone before" was a relatively unknown secret prototype beginning in 1992, whose goal was to create a version of the classic Mac OS that would run on Intel-compatible x86 personal computers. In partnership with Apple and with support from Intel, the project was instigated by Novell, which was looking to integrate its DR-DOS with the Mac OS GUI as a mutual response to the monopoly of Microsofts Windows 3.0 and MS-DOS. A team consisting of four from Apple and four from Novell was able to get the Macintosh Finder and some basic applications such as QuickTime, running smoothly on the x86 architecture. The project was canceled a year later in early 1993, but some of the code was later reused when porting the Mac OS to PowerPC.


3.6. Other projects Taligent

Taligent a portmanteau of "talent" and "intelligent" was the name of an object-oriented operating system and the company dedicated to producing it. Started as a project within Apple to provide a replacement for the classic Mac OS, it was later spun off into a joint venture with IBM as part of the AIM alliance, with the purpose of building a competing platform to Microsoft Cairo and NeXTSTEP. The development process never worked, and Taligent is often cited as an example of a project death march. Apple pulled out of the project in 1995 before the code had been delivered.


3.7. Other projects Copland

Copland was a project at Apple to create an updated version of the classic Mac OS. It was to have introduced protected memory, preemptive multitasking and a number of new underlying operating system features, yet still be compatible with existing Mac software. As originally planned, a follow-up release known as "Gershwin" would add multithreading and other advanced features. New features were added more rapidly than they could be completed, and the completion date slipped into the future with no sign of a release. In 1996, Apple decided to cancel the project outright and find a suitable third-party system to replace it. Copland development ended in August 1996, and in December 1996, Apple announced that it was buying NeXT for its NeXTSTEP operating system.


4. Related systems

Before the arrival of the Macintosh in 1984, Apples history of operating systems began with its Apple II series computers in 1977, which ran Apple DOS, ProDOS, and later GS/OS; the Apple III in 1980, which ran Apple SOS; and the Apple Lisa in 1983, which ran Lisa OS and later MacWorks XL, a Macintosh emulator. Apple also developed the Newton OS for its Newton personal digital assistant from 1993 to 1997.

In recent years, Apple has also launched several new operating systems based on the core of macOS, including iOS in 2007 for its iPhone, iPad, and iPod Touch mobile devices and in 2017 for its HomePod smart speakers; watchOS in 2015 for the Apple Watch; tvOS in 2015 for the Apple TV set-top box.