macOS

This article is about the current Apple operating system for Mac computers. For pre-2001 versions, seeClassic Mac OS.

macOS

Screenshot of theOS X El Capitandesktop indark mode
Developer	Apple Inc.
Written in	C C++ Objective-C Swift
OS family	Macintosh,Unix
Working state	Current
Source model	Closed source(withopen sourcecomponents)
Initial release	March 24, 2001(2001-03-24)
Latest release	10.15.5 Supplemental Update (June 1, 2020(2020-06-01))[±]
Latest preview	10.15.6 beta 4 (July 9, 2020(2020-07-09))[±]
Marketing target	Personal computing
Available in	40 languages
List of languages [as of macOS Catalina]: Arabic, Catalan, Croatian, Chinese (Hong Kong), Chinese (Simplified), Chinese (Traditional), Czech, Danish, Dutch, English (Australia), English (India), English (United Kingdom), English (United States), Finnish, French (Canada), French (France), German, Greek, Hebrew, Hindi, Hungarian, Indonesian, Italian, Japanese, Korean, Malay, Norwegian, Polish, Portuguese (Brazil), Portuguese (Portugal), Romanian, Russian, Slovak, Spanish (Latin America), Spanish (Spain), Swedish, Thai, Turkish, Ukrainian, Vietnamese
Update method	System Preferences(10.14+) Mac App Store(10.8–10.13) Software Update(10.0–10.7)
Platforms	Silicon(11.0-present) ARM64(11.0–present) x86-64(10.4.7–present) IA-32(10.4.4–10.6.8;discontinued) PowerPC(10.0–10.5.8;discontinued)
Kerneltype	Hybrid(XNU)
Default user interface	Aqua(Graphical)
License	Commercial software,proprietary software
Preceded by	Classic Mac OS
Official website	www.apple/macos
Support status
Supported

macOS,namedMac OS Xfrom 2001 to 2012 andOS Xuntil 2016,is anoperating system(OS) forcomputersmade byApple Inc.These are calledMacintoshcomputers, or Macs. It differs from other computers, as macOS is supposed to run only on Macs and not on other computers. However, people have made macOS run on computers that are not Macs. This is calledHackintoshand violates macOS' license agreement.

macOS first came out in 2001, and is completely different from the"classic" Mac OSthat it replaced. Unlike the first operating system, macOS (since OS X) is based on theUNIXoperating system (current versions haveUNIX 03certification) and on technologies developed between 1985 and 1997 atNeXT,a company that Apple co-founderSteve Jobscreated after leaving Apple in 1985. The "X"in Mac OS X and OS X is theRoman numeralfor the number 10 and is pronounced as such. The core of macOS is anopen sourceOS calledDarwin,but Darwin itself cannot run macOS software.

macOS releases are named after types of bigcats,orCalifornialandmarks, and has aversionnumber that starts with 10.0, 11.0, 12.0, 13.0, 14.0 & 15.0. The latest version of macOS ismacOS Sequoia (15.0).

Development

Simplified history ofUnix-likeoperating systems

Throughout the early 1990s, Apple had tried to create a "next-generation" OS to replace itsclassic Mac OS.The current macOS is aUNIXoperating system built on technology that had been developed atNeXTfrom the 1980s until Apple purchased the company in early 1997. That company was also founded bySteve Jobsfollowing his departure from Apple in 1985. There, theUnix-likeNeXTSTEPoperating system was developed, and then launched in 1989 (the "classic" Mac OS is much older, as it came out in 1984). Thekernelof NeXTSTEP is based upon theMach kernel,which was originally developed atCarnegie Mellon University,with additional kernel layers and low-leveluser spacecode from parts ofBerkeley Software Distribution(BSD). Itsgraphical user interfacewas built on top of anobject-orientedGUI toolkitusing theObjective-Cprogramming language.

Versions

macOS version information

Version	Codename	Date announced	Release date	Most recent version
RhapsodyDeveloper Release	Grail1Z4 / Titan1U	Unknown	August 31, 1997	DR2 (May 14, 1998)
Mac OS X Server 1.0	Hera		March 16, 1999	1.2v3 (October 27, 2000)
Mac OS X Developer Preview	Kodiak		March 16, 1999	DP4 (April 5, 2000)
Public Beta	Kodiak/Cheetah		September 13, 2000
Mac OS X 10.0	Cheetah	January 5, 2000	March 24, 2001	10.0.4 (June 22, 2001)
Mac OS X 10.1	Puma	July 18, 2001	September 25, 2001	10.1.5 (June 6, 2002)
Mac OS X 10.2	Jaguar	May 6, 2002	August 24, 2002	10.2.8 (October 3, 2003)
Mac OS X 10.3	Panther	June 23, 2003	October 24, 2003	10.3.9 (April 15, 2005)
Mac OS X 10.4	Tiger	May 4, 2004	April 29, 2005	10.4.11 (November 14, 2007)
Mac OS X 10.5	Leopard	June 26, 2006	October 26, 2007	10.5.8 (August 5, 2009)
Mac OS X 10.6	Snow Leopard	June 9, 2008	August 28, 2009	10.6.8 v1.1 (July 25, 2011)
Mac OS X 10.7	Lion	October 20, 2010	July 20, 2011	10.7.5 (September 19, 2012)
OS X 10.8	Mountain Lion	February 16, 2012	July 25, 2012	10.8.5 (12F45) (October 3, 2013)
OS X 10.9	Mavericks	June 10, 2013	October 22, 2013	10.9.5 (13F1112) (September 18, 2014)
OS X 10.10	Yosemite	June 2, 2014	October 16, 2014	10.10.5 (14F27) (August 13, 2015)
OS X 10.11	El Capitan	June 8, 2015	September 30, 2015	10.11.6 (15G1510) (May 15, 2017)
macOS 10.12	Sierra	June 13, 2016	September 20, 2016	10.12.6 (16G1212) (July 19, 2017)
macOS 10.13	High Sierra	June 5, 2017	September 25, 2017	10.13.6 (17G65) (July 9, 2018)
macOS 10.14	Mojave	June 4, 2018	September 24, 2018	10.14.6 (18G87) (August 1, 2019)
macOS 10.15	Catalina	June 3, 2019	October 7, 2019	10.15.5 Supplemental Update (19F101) (June 1, 2020)
macOS 11.0	Big Sur	June 22, 2020	November 12, 2020	11.7.9 (20G1426) (July 24, 2023)
macOS 12.0	Monterey	Jun 7, 2021	October 25, 2021	12.6.8 (21G725) (July 24, 2023)
macOS 13.0	Ventura	Jun 6, 2022	October 24, 2022	13.7.1 (22H210) (September 17, 2024)
macOS 14.0	Sonoma	June 5, 2023	September 26, 2023	14.7.1 (23H209) (September 23, 2024)
macOS 15.0	Sequoia	June 10, 2024	September 16, 2024	15.1 beta 1 (24B5046F) (September 17, 2024)

Public Beta: "Kodiak"

On September 13, 2000, Apple released a $29.95 preview of Mac OS X to ask users what they think of the new operating system so far. Apple stopped the Public Beta in March 2001 because of the recent release of OS X 10.0.

Version 10.0: "Cheetah"

On March 24, 2001 Apple released Mac OS X for the first time aka OS X v10.0 (codename Cheetah), but unfortunately, it was a failure due to its many computer bugs and glitches and its slow performance. Luckily this operating system version only stayed on the market up until September when it was moved up to a "higher level".

Version 10.1: "Puma"

Due to many problems and complaints about Cheetah, Apple directly got to work on releasing Puma, the next big cat in Mac OS X. It was released on September 24, 2001. Apple gave 10.0 users a free Mac OS X v10.1 install CD to make up for the flawed operating system before. As of January 7, 2002, Apple said Mac OS 9 and other previous operating systems from Apple were "going in the computer scrapyard" by the end of the month (January 31, 2002) and OS X would be the default and only operating system available on all Macs.

Version 10.2: "Jaguar"

Mac OS X 10.2 Jaguar was released on August 24, 2002 and was the first to have its codename in the version branding. The Happy Mac (which formerly appeared when a Mac was starting up) was replaced with a large gray apple logo with the startup sequence of OS X 10.2 Jaguar.

Version 10.3: "Panther"

Mac OS X 10.3 Panther was released on October 24, 2003 and was one of the biggest updates to OS X yet. It featured a new brushed metal interface, an updated Finder, and many more features from Jaguar the year before.

Version 10.4: "Tiger"

Tiger was released on April 29, 2005 and as stated by Apple, featured more than 200 new features. Among the new features, Tiger introduced Spotlight, Dashboard, Smart Folders, updated Mail program with Smart Mailboxes, QuickTime 7, Safari 2, Automaton, Voice-over, Core Image and Core Video. Apple released the first Power Intel Macs for Tiger on January 10, 2006. Tiger ran swell on these computers. It was also the last operating system to support the Aqua color scheme.

Version 10.5: "Leopard"

Mac OS X v10.5 Leopard was released on October 26, 2007. It was completely redesigned featuring a 3D Dock, a new purple color scheme, and over 200 new features. It had both support for PowerPC and Intel Macs too. Leopard was the last release to have support for PowerPC.

Version 10.6: "Snow Leopard"

Mac OS X Snow Leopard was released on August 28, 2009, and rather than featuring changes to the appearance, it featured "Under the hood" changes. Snow Leopard dropped support for PowerPC Macs too.

Version 10.7: "Lion"

OS X Lion was first shown to the public at the "Back to The Mac" event in 2010, announced more at WWDC 2011, and released on July 20, 2011. It featurediOS-like features such as the Launchpad, the Magic Trackpad coming to MacBooks, and a newsolar systemcolor scheme. Apple also removed Rosetta making it impossible to use PowerPC.

Version 10.8: "Mountain Lion"

OS X Mountain Lion was announced on February 18, 2012, and released on July 25, 2012. It adds more features from iOS 5 and 6 to the Mac such as notifications, messaging, game center, and gaming with people on iPhones, iPods, and iPads.

Version 10.9: "Mavericks"

OS X Mavericks was announced on June 10, 2013 at the 2013Worldwide Developers Conference.It adds the Maps and iBooks applications, as well as new Finder features, better multi-display support, power improvements, and a new version ofSafari.It was released on October 22, 2013. It was the first macOS version that was free.

Version 10.10: "Yosemite"

OS X Yosemite was announced in June 2014 at the 2014 Worldwide Developers Conference. It was in beta form for developers and those enrolled in the public beta programme to test until October 16, 2014 when it was released. It introduces a new flat design, following the aesthetic introduced withiOS 7.

Version 10.11: "El Capitan"

OS X 10.11 El Capitan was released on September 30, 2015 after being announced on June 8, 2015.Similar to Mac OS X 10.6 Snow Leopard, Apple described this release as containing "refinements to the Mac experience" and "improvements to system performance" rather than new features. Refinements include public transport built into the Maps application, GUI improvements to the Notes application, adopting San Francisco as the system font for clearer legibility, and the introduction of System Integrity Protection. The Metal API, first introduced iniOS 8,was also included in this operating system for "all Macs since 2012".

Version 10.12: "Sierra"

macOS 10.12 Sierra was announced on June 12, 2016and released to the public on September 20, 2016. New features include the addition of Siri, Optimized Storage, and updates to Photos, Messages, and iTunes

Version 10.13: "High Sierra"

The fall release of macOS 10.13 High Sierra was announced on June 5, 2017 at Apple's WWDC event. On September 12, 2017 at Apple's iPhone event, they announced its release to be September 25, 2017. Like OS X El Capitan and OS X Mountain Lion, High Sierra is a refinement-based update having very few new features. High Sierra uses the new Apple File System and includes enhancements to Safari, Photos, and Mail, among other changes.

Version 10.14: "Mojave"

Released on September 24, 2018. There are many additional features to the existing macOS apps. Some highlights are Dark Mode (UI theme & appearance), time shifts reflecting the hour of the day (desktop background), file stacks, edit features in quick look, continuity camera and Group FaceTime features also adds the screenshot app.

Version 10.15: "Catalina"

Released on October 7, 2019. This OS is included withlots of additional new featureslike sharing your screen to iPad (Sidecar) and is capable of running iPad apps. Catalina is the first version of macOS to exclusively support 64-bit applications. MacOS Catalina also split up iTunes into 3 apps: Music, Podcasts and Movies. Because of the removal of iTunes, syncing your devices is done in Finder.

Version 11.0: "Big Sur"

Released on November 12, 2020, macOS Big Sur changes the version number from 10 to 11. It now supports the ARM64 instruction set architecture (ISA), as Apple is transitioning the Mac to its own Apple Silicon based on the ARM64 platform. It brings the biggest design changes since the introduction of macOS (then called Mac OS X).

Version 12.0: "Monterey"

Released on October 25, 2021. macOS Monterey changes the version number from 11 to 12.

Version 13.0: "Ventura"

Released on October 24, 2022, macOS Ventura changes the version number from 12 to 13.

Version 14.0: "Sonoma"

Released on September 26, 2023, macOS Sonoma brings a set of new features to the Mac. With macOS Sonoma, desktop widgets is released which unlock a new way to personalize the Mac and get more done. Stunning new screen savers, updates to video conferencing and Safari, optimized gaming, among several other useful features are also released.

Version 15.0: "Sequoia"

Released on September 16, 2024, macOS Sequoia changes the version number from 14 to 15.

Architecture

At macOS's core is aPOSIX-compliant operating system built on top of theXNUkernel,with standard Unix facilities available from thecommand line interface.Apple has released this family of software as afreeandopen sourceoperating system namedDarwin.On top of Darwin, Apple layered a number of components, including theAquainterface and theFinder,to complete theGUI-based operating system which is macOS.

TheDarwinsubsystem in macOS is in charge of managing the file system, which includes the Unixpermissionslayer. In 2003 and 2005, twoMacworldeditors expressed criticism of the permission scheme; Ted Landau called misconfigured permissions "the most common frustration" in macOS, while Rob Griffiths suggested that some users may even have toreset permissionsevery day, a process which can take up to 15 minutes.More recently, another Macworld editor, Dan Frakes, called the procedure of repairing permissions vastly overused.He argues that macOS typically handles permissions properly without user interference, and resetting permissions should only be tried when problems emerge.

The architecture of macOS incorporates a layered design: the layered frameworks aid rapid development of applications by providing existing code for common tasks.Apple provides its ownsoftware developmenttools, most prominently anintegrated development environmentcalledXcode.Xcode provides interfaces tocompilersthat support severalprogramming languagesincludingC,C++,Objective-C,andSwift.For theApple–Intel transition,it was modified so that developers could build their applications as auniversal binary,which provides compatibility with both the Intel-based and PowerPC-based Macintosh lines.First and third-party applications can be controlled programatically using theAppleScriptframework,retained from theclassic Mac OS,or using the newerAutomatorapplication that offers pre-written tasks that do not require programming knowledge.

Related pages

• Macintosh

Other websites

• Apple Inc.
• macOS