DeveloperApple, Inc.
Source modelClosed source (with open source components)
Initial releaseSystem Software 1
(24 January 1984)
Latest releasemacOS Monterey 12.4
(16 May 2022)
Latest previewmacOS Ventura (build 22A5286j)
(22 June 2022)
Supported platformsx86_64, ARM64 (previously 68k, PPC and i386)
Kernel typeHybrid (XNU)
User interfaceAqua
LicenseProprietary (with open-source components)

macOS is a series of operating systems developed by Apple for their Macintosh platform. macOS is the second-most commonly used operating system after Microsoft Windows. It first became publicly available in 1984 with the release of the Macintosh 128k.

History[edit | edit source]

Classic[edit | edit source]

The original Macintosh System Software is based on the Lisa OS and UI concepts from Xerox PARC. It uses a monolithic architecture but lacks support for memory management, protected memory, access controls, and conflict-free extensions. Only one application at a time could be supported under System Software until version 5 when MultiFinder was introduced. In 1997, Apple rebranded the Macintosh System Software to Mac OS. Mac OS would continue to be developed until the introduction of Mac OS X, after which Apple only delivered minor updates to the classic Mac OS. The final minor updates were designed to ease the transition to OS X. Carbon, an API introduced with Mac OS 8, works as the transitional API for classic Mac OS and Mac OS X applications.

The classic Mac OS was originally written for the Motorola 68k architecture. The 68k architecture was used from 1984 to 1994, after which Apple transitioned to PowerPC. PowerPC would be used until the classic Mac OS's discontinuation in 2002. Classic Mac OS was based on a simple kernel design, which eventually became too limited and crash-prone for applications. In response, Apple bought NeXT and used NeXTSTEP as a base to develop Mac OS X.

The Classic Mac OS can run standalone, and under Mac OS X using the Classic system layer. Only certain versions of Mac OS 9 can run under the Classic system layer, and the layer itself was dropped after Mac OS X Tiger.

UNIX-based[edit | edit source]

macOS (formerly known as Mac OS X until 2012, or OS X until 2016) is the current incarnation of Mac OS. The first version released was Mac OS X Server in 1999. Unlike the classic Mac OS, it is based on NeXTSTEP and uses its frameworks and architectures. In 2006, Apple switched to Intel-based x86 processors in Macs. Support for PowerPC in Mac OS X was dropped in 2009. In 2012, Apple began to use the OS X moniker to brand Mac OS X alongside their other operating systems (watchOS, tvOS, iOS). In 2016, Apple began to use the macOS moniker to brand OS X alongside their other operating systems (watchOS, tvOS, iOS). At WWDC 2020, Apple declared that they would switch over to the Apple Silicon SoC in future Mac computers.

Timeline[edit | edit source]

Classic Mac OS versions

Name Versions Code name Release date Support end date Notes
System Software 1 1.0 - 1.1h N/A 1984-01-24 1985-04-01 First release of Mac OS for 68k-based systems
System Software 2 2.0 - 2.1 N/A 1985-04 1986-01-01
System Software 3 3.0 - 3.3 N/A 1986-01 1987-01-01
System Software 4 4.0 - 4.1.1 N/A 1987-01 1987-11-01
System Software 5 5.0 - 5.1 N/A 1987-10 1988-04-01
System Software 6 6.0 - N/A 1988-04 1992-03
Mac OS 7 7.0 - 7.6.1 Big Bang 1991-05-13 2001-05 First version to support PPC-based systems
Copland 8.0 Copland N/A N/A Never released
Mac OS 8 8.0 - 8.6 Tempo 1997-07-26 2001-05 Last version to support 68k-based systems
Mac OS 9 9.0 - 9.2.2 Sonata 1999-10-23 2002-02-01
Never released
Old version
Older version, still supported
Current stable version
Latest preview version
Future release

UNIX-based macOS versions

Name Version Darwin version Code name Release date Support end date Notes
Mac OS X Server 1.x 1.x Rhapsody 5.3 - 5.6[note 1] Rhapsody 1999-03-16 2001-03-24
Mac OS X Public Beta 10.0 1.2.1 Kodiak 2000-09-13 2001-03-24[note 2] Introduced the Aqua interface
Mac OS X Cheetah 1.3.1 Cheetah 2001-03-24 2004
Mac OS X Puma 10.1 1.4.1 / 5 Puma 2001-09-25 2005
Mac OS X Jaguar 10.2 6 Jaguar 2002-08-23 2006
Mac OS X Panther 10.3 7 Pinot 2003-10-24 2007
Mac OS X Tiger 10.4 8 Merlot, Chardonay 2005-04-29 2009-09 First version to support i386-based systems; Last version to support PowerPC G3 processors
Mac OS X Leopard 10.5 9 Chablis 2007-10-26 2011-06-23 First version to support x86_64-based systems; last version to support PPC-based systems
Mac OS X Snow Leopard 10.6 10 Snow Leopard 2009-08-28 2014-02-25 Last version to support i386-based systems and PPC-based applications via Rosetta
Mac OS X Lion 10.7 11 Barolo 2011-07-20 2014-10-16
OS X Mountain Lion 10.8 12 Zinfandel 2012-07-25 2015-09 Removes the 32-bit kernel and 32-bit EFI bootloader
OS X Mavericks 10.9 13 Cabernet 2013-10-22 2016-09
OS X Yosemite 10.10 14 Syrah 2014-10-16 2017-08
OS X El Capitan 10.11 15 Gala 2015-09-30 2018-08 Last version to support Intel processors without SSE4.1
macOS Sierra 10.12 16 Fuji 2016-09-20 2019-09
macOS High Sierra 10.13 17 Lobo 2017-09-25 2020-11-12
macOS Mojave 10.14 18 Liberty 2018-09-24 2021-10-25 Last version to support 32-bit applications
macOS Catalina 10.15 19 Jazz[note 3] 2019-10-07 TBD
macOS Big Sur 11 20 Golden Gate 2020-11-12 TBD First version to support ARM64-based systems
macOS Monterey 12 21 Star 2021-10-25 TBD Last version to support Intel processors without AVX2
macOS Ventura 13 22 Rome Fall 2022 TBD
Never released
Old version
Older version, still supported
Current stable version
Latest preview version
Future release

Notes[edit | edit source]

  1. Mac OS X Server 1.x is a direct descendant of the NeXTSTEP/OPENSTEP codebase and is not based on Darwin.
  2. Expired on 14 May 2001
  3. /usr/standalone/i386/SecureBoot.bundle/Contents/Resources/BuildManifest.plist | <string>macOSJazz</string>