OS X

"OSX" redirects here. For other uses, see OSX (disambiguation).

OS X

OS X El Capitan
Developer	Apple Inc.
Written in	C C++ Objective-C
OS family	Mac OS Unix
Working state	Current
Source model	Closed source (with open source components)
Initial release	March 24, 2001 (2001-03-24)
Latest release	10.11.5 (Build 15F34) (May 16, 2016 (2016-05-16)) [±]
Latest preview	10.11.6 Beta 1 (15G7a) (May 23, 2016 (2016-05-23)) [±]
Marketing target	Personal computing
Available in	34 languages
Update method	Mac App Store (10.8 and later) Previously: Software Update (10.0–10.7)
Platforms	x86-64 (10.4.7 and later) Discontinued: IA-32 (10.4.4–10.6.8) PowerPC (10.0–10.5.8)
Kernel type	Hybrid (XNU)
Default user interface	Graphical (Aqua)
License	Commercial software proprietary software
Preceded by	Mac OS 9
Official website	www.apple.com/osx

Simplified history of Unix-like operating systems

OS X (pronounced "o-ess-ten"; originally Mac OS X) is a series of Unix-based graphical interface operating systems (OS) developed and marketed by Apple Inc. It is designed to run on Macintosh computers, having been pre-installed on all Macs since 2002. OS X is the fourth most popular general purpose OS; within the market of desktop, laptop and home computers, and by web usage, OS X is the second most widely used desktop OS after Windows.

OS X was the successor to Mac OS 9, released in 1999, the final release of the "classic" Mac OS, which had been Apple's primary operating system since 1984. The first version released was Mac OS X Server 1.0 in 1999; a desktop version, Mac OS X v10.0 "Cheetah" followed on March 24, 2001. All consumer releases of OS X up to 2013 were named after big cats; for example, OS X v10.8 was referred to as "Mountain Lion". However, with the announcement of OS X Mavericks in June 2013, this was dropped in favor of Californian landmarks.

OS X, whose X is the Roman numeral for 10 and is a prominent part of its brand identity, is built on technologies developed at NeXT between the second half of the 1980s and Apple's purchase of the company in late 1996. The 'X' is also used to emphasize the relatedness between OS X and UNIX. UNIX 03 certification has been achieved for versions 10.5 for Intel CPUs, and versions 10.6 through 10.11. iOS, the mobile OS for the iPhone, iPod Touch, iPad, and the 2nd and 3rd generation Apple TV, shares the Unix-based core and many frameworks with OS X. An unnamed variant of v10.4 powers the first generation Apple TV. Apple also formerly issued a separate line of editions for server use.

The first releases of Mac OS X from 1999 to 2006 can run only on the PowerPC based Macs of the period. After Apple announced it would shift to using Intel x86 CPUs from 2006 onwards, Tiger and Leopard were released in versions for Intel and PowerPC processors. Snow Leopard is the first version released only for Intel Macs. Since the release of Mac OS X 10.7 "Lion", OS X has dropped support for 32-bit Intel processors as well. It now runs exclusively on 64-bit Intel CPUs.

The latest version of OS X is 10.11 "El Capitan", which was released to the public on September 30, 2015.

History

Main article: History of OS X

The heritage of what would become OS X had originated at NeXT, a company founded by Steve Jobs following his departure from Apple in 1985. There, the Unix-like NeXTSTEP operating system was developed, and then launched in 1989. The kernel of NeXTSTEP is based upon the Mach kernel, which was originally developed at Carnegie Mellon University, with additional kernel layers and low-level user space code derived from select parts of BSD. Its graphical user interface was built on top of an object-oriented GUI toolkit using the Objective-C programming language.

Throughout the early 1990s, Apple had tried to create a "next-generation" OS through the Taligent, Copland and Gershwin projects, although these were eventually abandoned. This led Apple to purchase NeXT in 1996, allowing NeXTSTEP, then called OPENSTEP, to serve as the basis for Apple's next generation OS. This purchase also led to Steve Jobs returning to Apple as first an interim and then the permanent CEO, shepherding the transformation of the programmer-friendly OPENSTEP into a system that would be adopted by Apple's primary market of home users and creative professionals. The project was first code named "Rhapsody" and then officially named "Mac OS X".

The first version of Mac OS X, Mac OS X Server 1.x, was a transitional product, featuring an interface resembling Mac OS. It was not compatible with software designed for the original Mac OS. Consumer releases of Mac OS X included more backward compatibility. Mac OS applications could be rewritten to run natively via the Carbon API; many could also be run directly through the Classic Environment with a reduction in performance.

The consumer version of Mac OS X was launched in 2001. Reviews were variable, with extensive praise for its sophisticated, glossy Aqua interface but criticising it for sluggish performance. With Apple's popularity at a low, the makers of several classic Mac applications such as FrameMaker and PageMaker declined to develop new versions of their software for OS X. Ars Technica columnist John Siracusa, who reviewed every major OS X release up to 10.10, described the early releases in retrospect as 'dog-slow, feature poor' and Aqua as 'unbearably slow and a huge resource hog'.

Apple rapidly developed several new releases of OS X. Siracusa's review of version 10.3, Panther, noted "It's strange to have gone from years of uncertainty and vaporware to a steady annual supply of major new operating system releases." Version 10.4, Tiger, reportedly shocked executives at Microsoft by offering a number of features, such as fast file searching and improved graphics processing, that Microsoft had spent several years struggling to add to Windows with acceptable performance.

In 2006, the first Intel Macs released used a specialized version of 10.4 "Tiger". In 2007, 10.5 "Leopard" was the first to run on both PowerPC and Intel Macs with the use of Universal Binaries. 10.6 "Snow Leopard" was the first version of OS X to drop support for PowerPC Macs.

As the operating system evolved, it moved away from the legacy Mac OS, with applications being added and removed. Targeting the consumer and media markets, Apple emphasised its new "digital lifestyle" applications such as the iLife suite, integrated home entertainment through the Front Row media center and the Safari web browser. With increasing popularity of the internet, Apple offered additional online services, including the .Mac, MobileMe and most recently iCloud products. It also began selling third-party applications through the Mac App Store.

New OS X versions also included modifications to the general interface, moving away from the striped gloss and transparency of the initial versions. Some applications began to use a brushed metal appearance, or non-pinstriped titlebar appearance in version 10.4. In Leopard, Apple announced a unification of the interface, with a standardised gray-gradient window style.

A key development for OS X was the announcement and release of the iPhone from 2007 onwards. While Apple's previous iPod mobile devices used a minimal operating system, the iPhone used an operating system based on OS X, which would later be called "iPhone OS" and then iOS. The simultaneous release of two operating systems based on the same frameworks placed tension on Apple, which cited the iPhone as forcing it to delay OS X Leopard. However, after Apple opened the iPhone to third-party developers its commercial success drew attention to OS X, with many iPhone software developers showing interest in Mac development.

In two succeeding versions, Lion and Mountain Lion, Apple moved some applications to a highly skeumorphic style of design inspired by contemporary versions of iOS, at the same time simplifying some elements by making controls such as scroll bars fade in when needed. This direction was, like brushed metal interfaces, unpopular with some users, although it continued a trend of greater animation and variety in the interface previously seen in design aspects such as the Time Machine backup utility, which presented past file versions against a swirling nebula, and the glossy translucent dock of Leopard and Snow Leopard. In addition, with Lion, Apple ceased to release separate server versions of OS X, selling server tools as a separate downloadable application. A review described the trend in OS X server as becoming 'cheaper and simpler...shifting its focus from large businesses to small ones.'

Apple removed the head of OS X development, Scott Forstall, in 2012, and switched designs towards a more minimal direction. Apple's new user interface design, using deep color saturation, text-only buttons and a minimal, 'flat' interface, was debuted in iOS 7 in 2013. With OS X engineers reportedly diverted to working on iOS 7, the version of OS X released in 2013, Mavericks, was something of a transitional release, with some of the skeumorphic design of iOS removed but the general interface of OS X largely unchanged. The next version, Yosemite, adopted a design similar to iOS 7 but with greater complexity suitable for an interface controlled with a mouse.

From 2012 onwards, OS X shifted to an annual release schedule similar to that of iOS, after releases generally coming every second year in the 10.3-10.7 period. It also steadily cut the cost of updates from Snow Leopard onwards, before removing upgrade fees altogether from 2013 onwards. Some journalists and third-party software developers have suggested that this decision, while allowing more rapid feature release, meant less opportunity to focus on stability, with no version of OS X recommendable for users requiring stability and performance above new features. Apple's 2015 update, El Capitan, was announced to focus specifically on stability and performance improvements.

In 2012, with the release of OS X 10.8, the "Mac" prefix was officially dropped in all references to the operating system name within its web site.

Description

OS X is the tenth major version of Apple's operating system for Macintosh computers. Previous Macintosh operating systems were named using Arabic numerals, e.g. Mac OS 8 and Mac OS 9. The letter X in OS X's name refers to the number 10, a Roman numeral. It is therefore correctly pronounced "ten" /ˈtɛn/ in this context. However, a common mispronunciation is "X" /ˈɛks/.

OS X's core is a POSIX compliant operating system (OS) built on top of the XNU kernel, with standard Unix facilities available from the command line interface. Apple has released this family of software as a free and open source operating system named Darwin. On top of Darwin, Apple layered a number of components, including the Aqua interface and the Finder, to complete the GUI-based operating system which is OS X.

OS X introduced a number of new capabilities to provide a more stable and reliable platform than its predecessor, Mac OS 9. For example, pre-emptive multitasking and memory protection improved the system's ability to run multiple applications simultaneously without them interrupting or corrupting each other. Many aspects of OS X's architecture are derived from OPENSTEP, which was designed to be portable, to ease the transition from one platform to another. For example, NeXTSTEP was ported from the original 68k-based NeXT workstations to x86 and other architectures before NeXT was purchased by Apple, and OPENSTEP was later ported to the PowerPC architecture as part of the Rhapsody project.

The most visible change was the Aqua theme. The use of soft edges, translucent colors, and pinstripes—similar to the hardware design of the first iMacs—brought more texture and color to the user interface when compared to what OS 9 and OS X Server 1.0's "Platinum" appearance had offered. According to John Siracusa, an editor of Ars Technica, the introduction of Aqua and its departure from the then conventional look "hit like a ton of bricks." Bruce Tognazzini (who founded the original Apple Human Interface Group) said that the Aqua interface in Mac OS X v10.0 represented a step backwards in usability compared with the original Mac OS interface. Third-party developers started producing skins for customizable applications and other operating systems which mimicked the Aqua appearance. To some extent, Apple has used the successful transition to this new design as leverage, at various times threatening legal action against people who make or distribute software with an interface the company says is derived from its copyrighted design. Since 2012, Apple has sold many of its Mac models with high-resolution Retina displays, and OS X and its APIs have extensive support for resolution-independent development on supporting high-resolution displays. Reviewers have described Apple's support for the technology as superior to that on Windows.

The architecture of OS X incorporates a layered design. The layered frameworks aid rapid development of applications by providing existing code for common tasks.

OS X includes its own software development tools, most prominently an integrated development environment called Xcode. Xcode provides interfaces to compilers that support several programming languages including C, C++, Objective-C, and Swift. For the Apple–Intel transition, it was modified so that developers could build their applications as a universal binary, which provides compatibility with both the Intel-based and PowerPC-based Macintosh lines. First and third-party applications can be controlled programatically using the AppleScript framework, retained from classic Mac OS, or using the newer Automator application.

The Darwin sub-system in Mac OS X is in charge of managing the filesystem, which includes the Unix permissions layer. In 2003 and 2005, two Macworld editors expressed criticism of the permission scheme; Ted Landau called misconfigured permissions "the most common frustration" in Mac OS X, while Rob Griffiths suggested that some users may even have to reset permissions every 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 OS X typically handles permissions properly without user interference, and resetting permissions should just be tried when problems emerge.

Applications may be installed by the user from any source, or from the Mac App Store, a marketplace of software maintained by Apple. All App Store applications run within a sandbox, restricting their ability to communicate with other programs or modify the core operating system. This provides increased user security but restricts the features they can offer.

Apple produces OS X applications, some of which are included and some sold separately. This includes iWork, Final Cut Pro, Logic Pro, iLife, and the database application FileMaker. With a move to online-only software distribution, Apple has moved most of the iLife and iWork applications to being freely available with lifetime updates on buying a new Mac, and shifted software sales for most applications to the Mac App Store rather than through physical media.

Distribution and languages

See also: Usage share of operating systems

As of September 2011, OS X is the second-most-active general-purpose client operating system in use on the World Wide Web, (after Microsoft Windows), with an 8.45% usage share according to statistics compiled by W3Counter. It is the most successful Unix-like desktop operating system on the web, estimated at over 5 times the usage of Linux (which has 1.5%).

There are twenty-two "System Languages" available for the user at the moment of installation (the "system language" is the entire operating system environment). As of Mac OS X Lion, the languages are Arabic, Chinese (Simplified), Chinese (Traditional), Czech, Danish, Dutch, English, Finnish, French, German, Hebrew, Hungarian, Italian, Japanese, Korean, Norwegian, Polish, Portuguese (Brazilian), Portuguese (European), Russian, Spanish, Swedish and Turkish. Input methods for typing in dozens of scripts can be chosen independently of the system language.

Compatibility

Software

Apple offered two main APIs to develop software natively for OS X: Cocoa and Carbon. Cocoa was a descendant of APIs inherited from OpenStep with no ancestry from Mac OS, while Carbon was an adaptation of Mac OS APIs, allowing Mac software to be minimally rewritten in order to run natively on OS X.

The Cocoa API was created as the result of a 1993 collaboration between NeXT Computer and Sun Microsystems. This heritage is highly visible for Cocoa developers, since the "NS" prefix is ubiquitous in the framework, standing variously for Nextstep or NeXT/Sun. The official OpenStep API, published in September 1994, was the first to split the API between Foundation and Application Kit and the first to use the "NS" prefix. Traditionally, Cocoa programs have been mostly written in Objective-C, with Java as an alternative. However, on July 11, 2005, Apple announced that "features added to Cocoa in Mac OS X versions later than 10.4 will not be added to the Cocoa-Java programming interface." OS X also used to support the Java Platform as a "preferred software package"—in practice this means that applications written in Java fit as neatly into the operating system as possible while still being cross-platform compatible, and that graphical user interfaces written in Swing look almost exactly like native Cocoa interfaces. Since 2014, Apple has promoted its new programming language Swift as the preferred language for software development on Apple platforms.

Apple's original plan with OS X was to require all developers to rewrite their software into the Cocoa APIs. This caused much outcry among existing Mac developers, who threatened to abandon the platform rather than invest in a costly rewrite, and the idea was shelved. To permit a smooth transition from Mac OS 9 to (Mac) OS X, the Carbon Application Programming Interface (API) was created. Applications written with Carbon were initially able to run natively on both Mac OS and OS X, although this ability was later dropped as OS X developed. Carbon was not included in the first product sold as "Mac OS X": the little-used original release of Mac OS X Server (now referred to as Mac OS X Server 1.x), which also did not include the Aqua interface. Apple limited further development of Carbon from the release of Leopard onwards, announcing Carbon applications would not receive the ability to run at 64-bit. As of 2015, a small number of older Mac OS X apps with heritage dating back to Mac OS still used Carbon, including Microsoft Office. Early versions of OS X could also run some Mac OS applications through the Classic Environment with performance limitations; this feature was removed from 10.5 onwards and all Macs using Intel processors.

Since OS X is POSIX compliant, many software packages written for the other Unix-like systems such as Linux can be recompiled to run on it, including much scientific and technical software. Third-party projects such as Homebrew, Fink, MacPorts and pkgsrc provide pre-compiled or pre-formatted packages. Apple and others have provided versions of the X Window System graphical interface which can allow these applications to run with an approximation of the OS X look-and-feel. The current Apple-endorsed method is the open-source XQuartz project; earlier versions could use the X11 application provided by Apple or before that the XDarwin project.

Applications can be distributed to Macs through normal ways such as downloading (with or without code signing, available via an Apple developer account) or through the Mac App Store, a process requiring Apple approval. Apps installed through the Mac App Store are sandboxed, with limited ability to exchange information with other applications or change system features: this has been cited as an advantage, by allowing users to install apps with confidence that they should not be able to damage their system, but also as blocking the platform's use by professional applications. Applications without any code signature cannot be run by default except from a computer's administrator account.

Hardware

Releases of OS X have steadily dropped compatibility with earlier Macs. As of late 2015, a period of stability has existed since 2012, with four successive OS X releases, from OS X Mountain Lion to OS X El Capitan, supporting all Macs released since early 2009 and some higher-end models released in 2007-8 if fitted with at least 2GB RAM. Key dividing lines have been the Apple transition to G4/5, and later to Intel processors.

For the early releases of Mac OS X, the standard hardware platform supported was the full line of Macintosh computers (laptop, desktop, or server) based on PowerPC G3, G4, and G5 processors. Later versions discontinued support for some older hardware; for example, Panther does not support "beige" G3s, and Tiger does not support systems that pre-date Apple's introduction of integrated FireWire ports (the ports themselves are not a functional requirement). Mac OS X v10.5 "Leopard", introduced October 2007, has dropped support for all PowerPC G3 processors and for PowerPC G4 processors with clock rates below 867 MHz. Mac OS X v10.6 "Snow Leopard" supports Macs with Intel processors, not PowerPC. Mac OS X 10.7 "Lion" requires a Mac with an Intel Core 2 Duo or newer processor.

Tools such as XPostFacto and patches applied to the installation disc have been developed by third parties to enable installation of newer versions of Mac OS X on systems not officially supported by Apple. This includes a number of pre-G3 Power Macintosh systems that can be made to run up to and including Mac OS X 10.2 Jaguar, all G3-based Macs which can run up to and including Tiger, and sub-867 MHz G4 Macs can run Leopard by removing the restriction from the installation DVD or entering a command in the Mac's Open Firmware interface to tell the Leopard Installer that it has a clock rate of 867 MHz or greater. Except for features requiring specific hardware (e.g. graphics acceleration, DVD writing), the operating system offers the same functionality on all supported hardware.

PowerPC versions of Mac OS X prior to Leopard retain compatibility with older Mac OS applications by providing an emulation environment called Classic, which allows users to run Mac OS 9 as a process within Mac OS X, so that most older applications run as they would under the older operating system. Classic is not supported on Intel-based Macs or in Mac OS X v10.5 "Leopard", but users still requiring Classic applications on Intel Macs can use the SheepShaver emulator to run Mac OS 9 on top of Leopard.

As most Macintosh components since the Intel transition are (or are similar to those) available on the open market (for example Intel processors, Hitachi hard drives, Intel/Radeon/Nvidia graphics cards) some technology-capable groups have developed that install OS X on non-Apple IBM PC compatible computers; these are referred to as Hackintoshes. This violates the EULA (and is therefore unsupported by Apple technical support, warranties etc.), but communities such as tonymacx86 that cater to personal users, who do not install for resale and profit, have generally been ignored by Apple. Hackintosh construction has been done to create computers models that are either lower cost or more powerful than those supplied by Apple. These self-made computers allow more flexibility and customization of hardware, but at a cost of leaving the user more responsible for their own machine - such as on matter of data integrity or security. Psystar, a business that did attempt to profit from selling OS X on non-Apple certified hardware, was sued by Apple in 2008.

PowerPC–Intel transition

Steve Jobs talks about the transition to Intel processors

Main article: Apple's transition to Intel processors

In April 2002, eWeek announced a rumor that Apple had a version of Mac OS X code-named Marklar, which ran on Intel x86 processors. The idea behind Marklar was to keep Mac OS X running on an alternative platform should Apple become dissatisfied with the progress of the PowerPC platform. These rumors subsided until late in May 2005, when various media outlets, such as The Wall Street Journal and CNET, announced that Apple would unveil Marklar in the coming months.

On June 6, 2005, Steve Jobs confirmed these rumors when he announced in his keynote address at the annual Apple Worldwide Developers Conference that Apple would be making the transition from PowerPC to Intel processors over the following two years, and that Mac OS X would support both platforms during the transition. Jobs also confirmed rumors that Apple had versions of Mac OS X running on Intel processors for most of its developmental life. The last time that Apple switched CPU families—from the Motorola 68K CPU to the IBM/Motorola PowerPC—Apple included a Motorola 68K emulator in the new OS that made almost all 68K software work automatically on the new hardware. Apple had supported the 68K emulator for 11 years, but stopped supporting it during the transition to Intel CPUs. Included in the new OS for the Intel-based Macs was Rosetta, a binary translation layer which enables software compiled for PowerPC Mac OS X to run on Intel Mac OS X machines up to version 10.6.8. Apple dropped support for Classic mode on the new Intel Macs. Third party emulation software such as Mini vMac, Basilisk II and SheepShaver provided support for some early versions of Mac OS. A new version of Xcode and the underlying command-line compilers supported building universal binaries that would run on either architecture.

PowerPC-only software is supported with Rosetta, though applications eventually had to be rewritten to run properly on the newer OS X for Intel. Apple initially encouraged developers to produce universal binaries with support for both PowerPC and x86. There is a performance penalty when PowerPC binaries run on Intel Macs through Rosetta. Moreover, some PowerPC software, such as kernel extensions and System Preferences plugins, are not supported on Intel Macs. Some PowerPC applications would not run on Intel OS X at all. Plugins for Safari need to be compiled for the same platform as Safari, so when Safari is running on Intel it requires plug-ins that have been compiled as Intel-only or universal binaries, so PowerPC-only plug-ins will not work. While Intel Macs are able to run PowerPC, x86, and universal binaries; PowerPC Macs support only universal and PowerPC builds.

Support for the PowerPC platform was dropped following the transition. In 2009, Apple announced at its Worldwide Developers Conference that Snow Leopard (version 10.6) would drop support for PowerPC processors and be Intel-only. Rosetta continued to be offered (as an optional download or installation choice) in Snow Leopard before being dropped in Lion. In addition, new versions of OS X first- and third-party software increasingly required Intel processors, including new versions of iLife, iWork, Aperture and Logic Pro released in the 2010-11 period.

Features

One of the major differences between the previous versions of Mac OS and OS X was the addition of the Aqua GUI, a graphical user interface with water-like elements. Every window element, text, graphic, or widget is drawn on-screen using spatial anti-aliasing technology. ColorSync, a technology introduced many years before, was improved and built into the core drawing engine, to provide color matching for printing and multimedia professionals. Also, drop shadows were added around windows and isolated text elements to provide a sense of depth. New interface elements were integrated, including sheets (document modal dialog boxes attached to specific windows) and drawers.

Apple has continued to change aspects of the OS X appearance and design, particularly with tweaks to the appearance of windows and the menu bar. One example of a UI behavioral change is that previewed video and audio files no longer have progress bars in column view; instead, they have mouse-over start and stop buttons as of 10.5.

The human interface guidelines published by Apple for Mac OS X are followed by many applications, giving them consistent user interface and keyboard shortcuts. In addition, new services for applications are included, which include spelling and grammar checkers, special characters palette, color picker, font chooser and dictionary; these global features are present in every Cocoa application, adding consistency. The graphics system OpenGL composites windows onto the screen to allow hardware-accelerated drawing. This technology, introduced in version 10.2, is called Quartz Extreme, a component of Quartz. Quartz's internal imaging model correlates well with the Portable Document Format (PDF) imaging model, making it easy to output PDF to multiple devices. As a side result, PDF viewing and creating PDF documents from any application are built-in features.

In version 10.3, Apple added Exposé, a feature which includes three functions to help accessibility between windows and desktop. Its functions are to instantly display all open windows as thumbnails for easy navigation to different tasks, display all open windows as thumbnails from the current application, and hide all windows to access the desktop. Also, FileVault was introduced, which is an optional encryption of the user's files with Advanced Encryption Standard (AES-128).

Features introduced in version 10.4 include Automator, an application designed to create an automatic workflow for different tasks; Dashboard, a full-screen group of small applications called desktop widgets that can be called up and dismissed in one keystroke; and Front Row, a media viewer interface accessed by the Apple Remote. Moreover, the Sync Services were included, which is a system that allows applications to access a centralized extensible database for various elements of user data, including calendar and contact items. The operating system then managed conflicting edits and data consistency.

As of version 10.5, all system icons are scalable up to 512×512 pixels, to accommodate various places where they appear in larger size, including for example the Cover Flow view, a three-dimensional graphical user interface included with iTunes, the Finder, and other Apple products for visually skimming through files and digital media libraries via cover artwork. This version includes Spaces, a virtual desktop implementation which enables the user to have more than one desktop and display them in an Exposé-like interface. Mac OS X v10.5 includes an automatic backup technology called Time Machine, which provides the ability to view and restore previous versions of files and application data; and Screen Sharing was built in for the first time.

Finder is a file browser allowing quick access to all areas of the computer, which has been modified throughout subsequent releases of Mac OS X. Quick Look is part of Mac OS X Leopard's Finder. It allows for dynamic previews of files, including videos and multi-page documents, without opening their parent applications. Spotlight search technology, which is integrated into the Finder since Mac OS X Tiger, allows rapid real-time searches of data files; mail messages; photos; and other information based on item properties (meta data) and/or content. Mac OS X makes use of a Dock, which holds file and folder shortcuts as well as minimized windows.

As the Far East and China in particular are a major Apple target market where Apple is a high-status luxury brand, recent updates have added increasing support for Chinese characters and interconnections with popular Chinese social networks. OS X has developed support for emoji ideograms by including the proprietary Apple Color Emoji font. Apple has also sought to connect OS X with Western social networks such as Twitter and Facebook through the addition of share buttons for content such as pictures and text.

Reflecting its popularity with design users, OS X has system support for a variety of professional video and image formats. It also includes an extensive pre-installed font library, featuring many prominent brand-name designs.

Versions

Mac OS X version information

Version	Codename	Processor support	Application support	Kernel	Date announced	Release date	Most recent version
Rhapsody Developer Release	Grail1Z4 / Titan1U	32-bit PowerPC	32-bit PowerPC	32-bit	Unknown	August 31, 1997	DR2 (May 14, 1998)
Mac OS X Server 1.0	Hera				Unknown	March 16, 1999	1.2v3 (October 27, 2000)
Mac OS X Developer Preview	Unknown				May 11, 1998	March 16, 1999	DP4 (April 5, 2000)
Public Beta	Kodiak				Unknown	September 13, 2000	N/A
Mac OS X 10.0	Cheetah				Unknown	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	32/64-bit PowerPC			May 6, 2002	August 24, 2002	10.2.8 (October 3, 2003)
Mac OS X 10.3	Panther	32/64-bit PowerPC			June 23, 2003	October 24, 2003	10.3.9 (April 15, 2005)
Mac OS X 10.4	Tiger	32/64-bit PowerPC and Intel	32/64-bit PowerPC and Intel		May 4, 2004	April 29, 2005	10.4.11 (November 14, 2007)
Mac OS X 10.5	Leopard		32/64-bit PowerPC and Intel		June 26, 2006	October 26, 2007	10.5.8 (August 5, 2009)
Mac OS X 10.6	Snow Leopard	32/64-bit Intel	32/64-bit Intel 32-bit PowerPC	32/64-bit	June 9, 2008	August 28, 2009	10.6.8 v1.1 (July 25, 2011)
Mac OS X 10.7	Lion	64-bit Intel	32/64-bit Intel		October 20, 2010	July 20, 2011	10.7.5 (September 19, 2012)
OS X 10.8	Mountain Lion			64-bit	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	10.11.1 (15B42) (October 21, 2015)

^{Note 1} The PowerMac G5 had special Jaguar builds.

^{Note 2} Tiger did not support 64-bit GUI applications, only 64-bit CLI applications.

^{Note 3} 32-bit PowerPC applications were supported on Intel processors with Rosetta.

With the exception of Mac OS X Server 1.0 and the original public beta, OS X versions were named after big cats until version 10.9, when Apple switched to using California locations. Prior to its release, version 10.0 was code named "Cheetah" internally at Apple, and version 10.1 was code named internally as "Puma". After the immense buzz surrounding version 10.2, codenamed "Jaguar", Apple's product marketing began openly using the code names to promote the operating system. 10.3 was marketed as "Panther", 10.4 as "Tiger", 10.5 as "Leopard", 10.6 as "Snow Leopard", 10.7 as "Lion", 10.8 as "Mountain Lion", and 10.9 as "Mavericks". "Panther", "Tiger" and "Leopard" are registered as trademarks of Apple, but "Cheetah", "Puma" and "Jaguar" have never been registered. Apple has also registered "Lynx" and "Cougar" as trademarks, though these were allowed to lapse. Computer retailer Tiger Direct sued Apple for its use of the name "Tiger". On May 16, 2005 a US federal court in the Southern District of Florida ruled that Apple's use did not infringe on Tiger Direct's trademark.

Public Beta: "Kodiak"

Main article: Mac OS X Public Beta

On September 13, 2000, Apple released a $29.95 "preview" version of Mac OS X (internally codenamed Kodiak) in order to gain feedback from users.

The "PB" as it was known marked the first public availability of the Aqua interface and Apple made many changes to the UI based on customer feedback. Mac OS X Public Beta expired and ceased to function in Spring 2001.

Version 10.0: "Cheetah"

Main article: Mac OS X v10.0

File:MacOSX10-0screenshot.png

Screenshot of OS X 10.0

On March 24, 2001, Apple released Mac OS X v10.0 (internally codenamed Cheetah). The initial version was slow, incomplete, and had very few applications available at the time of its launch, mostly from independent developers. While many critics suggested that the operating system was not ready for mainstream adoption, they recognized the importance of its initial launch as a base on which to improve. Simply releasing Mac OS X was received by the Macintosh community as a great accomplishment, for attempts to completely overhaul the Mac OS had been underway since 1996, and delayed by countless setbacks. Following some bug fixes, kernel panics became much less frequent.

Version 10.1: "Puma"

Main article: Mac OS X v10.1

Later that year on September 25, 2001, Mac OS X v10.1 (internally codenamed Puma) was released. It featured increased performance and provided missing features, such as DVD playback. Apple released 10.1 as a free upgrade CD for 10.0 users, in addition to the US$129 boxed version for people running Mac OS 9. It was discovered that the upgrade CDs were full install CDs that could be used with Mac OS 9 systems by removing a specific file; Apple later re-released the CDs in an actual stripped-down format that did not facilitate installation on such systems. On January 7, 2002, Apple announced that Mac OS X was to be the default operating system for all Macintosh products by the end of that month.

Version 10.2: "Jaguar"

Main article: Mac OS X v10.2

On August 23, 2002, Apple followed up with Mac OS X v10.2 "Jaguar", the first release to use its code name as part of the branding. It brought great raw performance improvements, a sleeker look, and many powerful user-interface enhancements (over 150, according to Apple ), including Quartz Extreme for compositing graphics directly on an ATI Radeon or Nvidia GeForce2 MX AGP-based video card with at least 16 MB of VRAM, a system-wide repository for contact information in the new Address Book, and an instant messaging client named iChat. The Happy Mac which had appeared during the Mac OS startup sequence for almost 18 years was replaced with a large grey Apple logo with the introduction of Mac OS X v10.2.

Version 10.3: "Panther"

Main article: Mac OS X Panther

Mac OS X v10.3 "Panther" was released on October 24, 2003. In addition to providing much improved performance, it also incorporated the most extensive update yet to the user interface. Panther included as many or more new features as Jaguar had the year before, including an updated Finder, incorporating a brushed-metal interface, Fast user switching, Exposé (Window manager), FileVault, Safari, iChat AV (which added videoconferencing features to iChat), improved Portable Document Format (PDF) rendering and much greater Microsoft Windows interoperability. Support for some early G3 computers such as "beige" Power Macs and "WallStreet" PowerBooks was discontinued.

Version 10.4: "Tiger"

Main article: Mac OS X Tiger

File:TigerDesk.png

Screenshot of Tiger

Mac OS X v10.4 "Tiger" was released on April 29, 2005. Apple stated that Tiger contained more than 200 new features. As with Panther, certain older machines were no longer supported; Tiger requires a Mac with 256MB and a built-in FireWire port. Among the new features, Tiger introduced Spotlight, Dashboard, Smart Folders, updated Mail program with Smart Mailboxes, QuickTime 7, Safari 2, Automator, VoiceOver, Core Image and Core Video. The initial release of the Apple TV used a modified version of Tiger with a different graphical interface and fewer applications and services. On January 10, 2006, Apple released the first Intel-based Macs along with the 10.4.4 update to Tiger. This operating system functioned identically on the PowerPC-based Macs and the new Intel-based machines, with the exception of the Intel release dropping support for the Classic environment.

Version 10.5: "Leopard"

Main article: Mac OS X Leopard

Mac OS X v10.5 "Leopard" was released on October 26, 2007. It was called by Apple "the largest update of Mac OS X". It brought more than 300 new features. Leopard supports both PowerPC- and Intel x86-based Macintosh computers; support for the G3 processor was dropped and the G4 processor required a minimum clock rate of 867 MHz, and at least 512 MB of RAM to be installed. The single DVD works for all supported Macs (including 64-bit machines). New features include a new look, an updated Finder, Time Machine, Spaces, Boot Camp pre-installed, full support for 64-bit applications (including graphical applications), new features in Mail and iChat, and a number of new security features. Leopard is an Open Brand UNIX 03 registered product on the Intel platform. It was also the first BSD-based OS to receive UNIX 03 certification. Leopard dropped support for the Classic Environment and all Classic applications. It was the final version of Mac OS X to support the PowerPC architecture.

Version 10.6: "Snow Leopard"

Main article: Mac OS X Snow Leopard

Mac OS X v10.6 "Snow Leopard" was released on August 28, 2009. Rather than delivering big changes to the appearance and end user functionality like the previous releases of Mac OS X, Snow Leopard focused on "under the hood" changes, increasing the performance, efficiency, and stability of the operating system. For most users, the most noticeable changes were: the disk space that the operating system frees up after a clean install compared to Mac OS X 10.5 Leopard, a more responsive Finder rewritten in Cocoa, faster Time Machine backups, more reliable and user friendly disk ejects, a more powerful version of the Preview application, as well as a faster Safari web browser. Snow Leopard only supported machines with Intel CPUs, required at least 1 GB of RAM, and dropped default support for applications built for the PowerPC architecture (Rosetta could be installed as an additional component to retain support for PowerPC-only applications).

Mac OS X v10.6 also featured new 64-bit technology capable of supporting greater amounts of RAM, improved support for multi-core processors through Grand Central Dispatch, and advanced GPU performance with OpenCL.

An update introduced support for the Mac App Store, Apple's digital distribution platform for OS X applications.

Mac OS X Lion was announced at WWDC 2011 at Moscone West.

Version 10.7: "Lion"

Main article: Mac OS X Lion

Mac OS X v10.7 "Lion" was released on July 20, 2011. It brought developments made in Apple's iOS, such as an easily navigable display of installed applications (Launchpad) and a greater use of multi-touch gestures, to the Mac. This release removed Rosetta, making it incapable of running PowerPC applications.

Changes made to the GUI (Graphical User Interface) include the Launchpad (similar to the home screen of iOS devices), auto-hiding scrollbars that only appear when they are being used, and Mission Control, which unifies Exposé, Spaces, Dashboard, and full-screen applications within a single interface. Apple also made changes to applications: they resume in the same state as they were before they were closed (similar to iOS). Documents auto-save by default.

Version 10.8: "Mountain Lion"

Main article: OS X Mountain Lion

OS X v10.8 "Mountain Lion" was released on July 25, 2012. It incorporates some features seen in iOS 5, which include Game Center, support for iMessage in the new Messages messaging application, and Reminders as a to-do list app separate from iCal (which is renamed as Calendar, like the iOS app). It also includes support for storing iWork documents in iCloud. Notification Center, which makes its debut in Mountain Lion, is a desktop version similar to the one in iOS 5.0 and higher. Application pop-ups are now concentrated on the corner of the screen, and the Center itself is pulled from the right side of the screen. Mountain Lion also includes more Chinese features including support for Baidu as an option for Safari search engine, QQ, 163.com and 126.com services for Mail, Contacts and Calendar, Youku, Tudou and Sina Weibo are integrated into share sheets.

Starting with Mountain Lion Apple software updates (including the OS) are distributed via the App Store. This updating mechanism replaced the Apple Software Update utility.

File:Macintosh OS X Mavericks representation.png

A screenshot of OS X Mavericks

Version 10.9: "Mavericks"

Main article: OS X Mavericks

OS X 10.9 "Mavericks" was released on October 22, 2013. This is a free upgrade to all users running OS X Snow Leopard or later, and has a 64-bit Intel processor. Its changes include the addition of the previously iOS-only Maps and iBooks applications, improvements to the Notification Center, enhancements to several applications, and many under-the-hood improvements.

Version 10.10: "Yosemite"

Main article: OS X Yosemite

OS X 10.10 "Yosemite" was released on October 16, 2014. It features a redesigned user interface skin similar to iOS 7, intended to feature a more minimal, text-based 'flat' design, with use of translucency effects and intensely saturated colours. Apple's showcase new feature in Yosemite is Handoff, which enables users with iPhones running iOS 8.1 or later to answer phone calls, receive and send SMS messages, and complete unfinished iPhone emails on their Mac.

Version 10.11: "El Capitan"

Main article: OS X El Capitan

Screenshot of El Capitan

OS X 10.11 "El Capitan" was released on September 30, 2015. 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, as well as adopting San Francisco as the system font. Metal API, an application enhancing software, had debuted in this operating system, being available to "all Macs since 2012".

Updating methods

"Software Update" redirects here. For software updates in general, see Patch (computing).

OS X can be updated using the Mac App Store. Until OS X Mountain Lion, the updating method was to use Software Update; in Mountain Lion, Software Update was merged into the Mac App Store.

Software Update is a software tool by Apple Inc. that installs the latest version of Apple software on computers running OS X. It was originally introduced to Mac users in Mac OS 9. A Windows version has been available since the introduction of iTunes 7, under the name Apple Software Update. Software Update automatically informs users of new updates. The program is part of the CoreServices in OS X. Software Update can be set to check for updates daily, weekly, monthly, or not at all; in addition, it can download and store the associated .pkg file (the same type used by Installer) to be installed at a later date and maintains a history of installed updates. Software Updates consist of incremental updates of the Mac OS and its applications, Security Updates, device drivers and firmware updates. All software updates require the user to enter their administrative password, as with all consequential system changes. Some updates require a system restart. Starting with OS X 10.5, updates that require a reboot log out the user prior to installation and automatically restart the computer when complete; in earlier versions, the updates are installed, but critical files are not replaced until the next system startup.

Functionality

Software Update

The program is part of the CoreServices in OS X. Software Update can be set to check for updates daily, weekly, monthly, or not at all; in addition, it can download and store the associated .pkg file (the same type used by Installer) to be installed at a later date and maintains a history of installed updates.

Software Updates consist of incremental updates of the Mac OS and its applications, Security Updates, device drivers and firmware updates. All software updates require the user to enter their administrative password, as with all consequential system changes. Some updates require a system restart. Starting with OS X 10.5, updates that require a reboot log out the user prior to installation and automatically restart the computer when complete; in earlier versions, the updates are installed, but critical files are not replaced until the next system startup.

Criticism

Software Update

Apple Software Update under Wireshark

Software Update uses predictable TCP sequence numbers and plain text HTTP. Neither the command line nor GUI tools allow the user to use unpredictable sequence numbers or HTTPS. Mac OS X 10.8 uses HTTPS by default and allows a user to downgrade to HTTP, but still uses predictable sequence numbers.

Apple's Software Update download server allows weak and wounded ciphers, and the server does not support secure renegotiation. Performing test connections using openssl s_client showed the server would agree to RC4-MD5. In fact, ARC4-MD5 was the server's preferred cipher. While confidentiality is not an issue (everyone gets the same update), authenticity is an issue and user must have assurances that they are communicating with the expected server and the communications are not tampered (MD5 is considered insecure by the cryptographic community, and should not be used).

In March 2008, Apple began offering its web browser, Safari, through Apple Software Update for Windows. The Safari download was selected by default for installation by Apple Software Update. After significant criticism from the community, Apple changed its policy and Safari was no longer selected by default for download. Apple Software Update for Windows now offers new software and an optional download, in addition to updates for already-installed software.

Reception

Criticism

Operating system designer Linus Torvalds has criticized the default file system of OS X, HFS Plus. He says it is "probably the worst file-system ever" whose design is "actively corrupting user data". He criticizes the case insensitivity of file names, a design made worse when Apple extended the file system to support Unicode.

Initially, HFS+ was designed for classic Mac OS, which runs on big-endian PowerPC systems. When Apple switched Macintosh to little-endian Intel processors, it continued to use big-endian byte order on HFS+ file systems. As a result, OS X on current Macs must do byte swap when it reads files.

Promotion

As a devices company, most large-scale Apple promotion for OS X has been part of the sale of Macs, with promotion of OS X updates generally focused on existing users, promotion at Apple Store and other retail partners, or through events for developers. In large-scale advertising campaigns, Apple specifically promoted OS X as better for handling media and other home-user applications, and comparing OS X with the critical reception Microsoft received for its long-awaited Windows Vista update.

See also

• A/UX
• MkLinux
• Comparison of BSD operating systems
• Comparison of operating systems
• List of OS X technologies
• List of Macintosh software
• List of operating systems
• Market share of operating systems
• Dock (OS X)

External links

• OS X – official website at Apple
• Downloads page – listings for third party OS X software at Apple
• 22. October 2013, Poornima Gupta, Edwin Chan: Apple gives away Mac software, unveils iPad Air, reuters.com