macOS

macOS

Developer	Apple, Inc.
Source model	Closed source (with open source components)
Initial release	System Software 1 (24 January 1984)
Latest release	macOS Monterey 12.4 (16 May 2022)
Latest preview	macOS Ventura (build 22A5286j) (22 June 2022)
Supported platforms	x86_64, ARM64 (previously 68k, PPC and i386)
Kernel type	Hybrid (XNU)
User interface	Aqua
License	Proprietary (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

Classic

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

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

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 - 6.0.8.1	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
Legend: 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	Rhapsody	1999-03-16	2001-03-24
Mac OS X Public Beta	10.0	1.2.1	Kodiak	2000-09-13	2001-03-24	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	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
Legend: Never released Old version Older version, still supported Current stable version Latest preview version Future release