OS X

OS X desktop Screenshot of Mac OS X v10.7 "Lion"
Company / developer	Apple Inc.
Programmed in	C, C++, Objective-C[1][2]
OS family	Mac OS, Unix[3][4][5]
Working state	Current
Source model	Closed source (with open source components)
Initial release	March 24, 2001; 11 years ago  (2001-03-24)
Latest stable release	10.7.4 (Build 11E53)
Latest unstable release	10.8 (Build ) 12A193i[6] / May 1, 2012; 56 days ago  (2012-05-01)
Marketing target	Personal computing
Available language(s)	Multi-lingual
Update method	Apple Software Update Mac App store
Supported platforms	PowerPC: versions 10.0 through 10.5 IA-32: versions 10.4 through 10.6 x86-64: versions 10.4 through 10.8
Kernel type	Hybrid (XNU)
Default user interface	Graphical (Aqua)
License	Proprietary EULA
Preceded by	Mac OS 9
Official website	www.apple.com/macosx

OS X ( /oʊ ˌɛs ˈtɛn/),^[7] formerly Mac OS X,^[8] is a series of Unix-based graphical interface operating systems developed, marketed, and sold by Apple Inc. OS X (officially) runs exclusively on Macintosh computers and has been pre-loaded on all Macs since 2002.

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. It 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.

OS X is a UNIX-like operating system that originally ran on PowerPC-based Macs. In 2006, the first Intel Macs had a specialized version of Mac OS X v10.4 "Tiger". in 2007, Mac OS X 10.5 "Leopard",^[4] was the first to have UNIX 03 certification and run on both PowerPC and Intel Macs with the use of Universal Binaries. Mac OS X 10.6 "Snow Leopard" was the first version of OS X to drop support for PowerPC Macs and run solely on Intel's x86-based processors. Mac OS X 10.7 "Lion" was the first version of OS X to drop support for 32-bit processors and run exclusively on 64-bit CPUs.

The first version released was Mac OS X Server 1.0 in 1999, and a desktop version, Mac OS X v10.0 "Cheetah" followed on March 24, 2001. Releases of OS X are named after big cats: for example, Mac OS X v10.7 is referred to by Apple and users as "Lion". The server edition, Mac OS X Server, is architecturally identical to its desktop counterpart, and includes tools to facilitate management of workgroups of OS X machines, and to provide network services. OS X Server is preloaded on the Server models of Mac Pro and Mac Mini, but is also available for purchase separately.

iOS, which runs on the iPhone, iPod Touch,^[9] iPad, and the 2nd and 3rd generation Apple TV,^[10] shares the Darwin core and many frameworks with OS X. An unnamed variant of Mac OS X 10.4 powered the first generation Apple TV.^[11]

This article is part of the OS X series.

Features

History

Transition to Intel processors

Architecture

Technologies

List of applications

List of games

Components

Versions

Kodiak (Public Beta) ∙ Cheetah (10.0)

Puma (10.1) ∙ Jaguar (10.2)

Panther (10.3) ∙ Tiger (10.4)

Leopard (10.5) ∙ Snow Leopard (10.6)

Lion (10.7) ∙ Mountain Lion (10.8)

History[link]

OS X is based upon the Mach kernel. Certain parts from FreeBSD's and NetBSD's implementation of Unix were incorporated in NeXTSTEP, the core of Mac OS X. NeXTSTEP was the graphical, object-oriented, and UNIX-based operating system developed by Steve Jobs' company NeXT after he left Apple in 1985.^[12] While Jobs was away from Apple, Apple tried to create a "next-generation" OS through the Taligent, Copland and Gershwin projects, with little success.^[13]

Eventually, NeXT's OS, then called OPENSTEP, was selected to be the basis for Apple's next OS, and Apple purchased NeXT outright.^[14] Steve Jobs returned to Apple as interim CEO, and later became 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 known as Rhapsody and was later renamed to Mac OS X.^[15]

Mac OS X Server 1.x, was incompatible with software designed for the original Mac OS and had no support for Apple's own IEEE 1394 interface (FireWire). Mac OS X 10.x included more backward compatibility through Classic and more functionality by introducing the Carbon API as well as FireWire support. As the operating system evolved, it moved away from the legacy Mac OS to an emphasis on new "digital lifestyle" applications such as the iLife suite, enhanced business applications (iWork), and integrated home entertainment (the Front Row media center).^[16] Each version also included modifications to the general interface, such as the brushed metal appearance added in version 10.3, the non-pinstriped titlebar appearance in version 10.4, and in 10.5 the removal of the previous brushed metal styles in favor of the "Unified" gradient window style.^[17][18]

In 2012, with the release of OS X Lion, the "Mac" prefix was officially dropped in all references to the operating system name within marketing materials - and with OS X Mountain Lion "Mac" was dropped in all references within the operating system itself.^[19] However, Apple websites and other marketing material continue use both "Mac OS X" and "OS X" interchangeably.

Description[link]

Error: image is invalid or non-existent

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.^[1][2] However, due to the tenth version being the first to be based on Unix origins, and a reason for the Roman numeral to be used for the number 10 in its honour, a common pronunciation is "X" (/ˈɛks/).^[3]

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.^[4]

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.^[5] 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,^[6] 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."^[7] 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.^[8][9] 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.^[10]

The architecture of OS X incorporates a layered design.^[11] The layered frameworks aid rapid development of applications by providing existing code for common tasks.^[12]

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 Java. 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.^[13]

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,^[14] while Rob Griffiths suggested that some users may even have to reset permissions every day, a process which can take up to 15 minutes.^[15] More recently, another Macworld editor, Dan Frakes, called the procedure of repairing permissions vastly overused.^[16] He argues that OS X typically handles permissions properly without user interference, and resetting permissions should just be tried when problems emerge.^[17]

Distribution and languages[link]

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.^[18] 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%).^[18]

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.^[19]

Compatibility[link]

Software[link]

The APIs that OS X inherited from OpenStep are not backward compatible with earlier versions of Mac OS. These APIs were created as the result of a 1993 collaboration between NeXT Computer and Sun Microsystems and are now referred to by Apple as Cocoa. 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.^[6] Apple's Rhapsody project would have required all new development to use these APIs, causing much outcry among existing Mac developers. All Mac software that did not receive a complete rewrite to the new framework would run in the equivalent of the Classic environment. 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 can be executed natively on both systems. Carbon was not included in the first product sold as "Mac OS X": Mac OS X Server (now referred to as Mac OS X Server 1.x).

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. 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."^[20]

Since OS X is POSIX compliant, many software packages written for the *BSDs, Linux, or other Unix-like systems can be recompiled to run on it. Projects such as Homebrew, Fink, MacPorts and pkgsrc provide pre-compiled or pre-formatted packages. From version 10.3 to version 10.7, OS X included X11.app, Apple's version of the X Window System graphical interface for Unix applications, as an optional component during installation.^[21] Up to and including Mac OS X v10.4 (Tiger), Apple's implementation was based on the X11 Licensed XFree86 4.3 and X11R6.6. All bundled versions of X11 feature a window manager which is similar to the OS X look-and-feel and has fairly good integration with Mac OS X, also using the native Quartz rendering system. Earlier versions of OS X (in which X11 has not been bundled) can also run X11 applications using XDarwin. With the introduction of version 10.5 Apple switched to the X.org variant of X11.^[22] Version Mac OS X 10.7 "Lion" use X.org Server version 1.10.x^[23] Starting with OS X Mountain Lion, X11 will not be bundled in OS X; instead, it will have to be installed from, for example, the open source XQuartz project.^[24]

Hardware[link]

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,^[25] 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.

Apple–Intel transition[link]

Steve Jobs talks about the 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.^[26] These rumors subsided until late in May 2005, when various media outlets, such as the Wall Street Journal^[27] and CNET,^[28] 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 is Rosetta, a binary translation layer which enables software compiled for PowerPC Mac OS X to run on Intel Mac OS X machines. Apple dropped support for Classic mode on the new Intel Macs. Third party emulation software such as Mini vMac, Basilisk II and SheepShaver provides support for some early versions of Mac OS. A new version of Xcode and the underlying command-line compilers support building universal binaries that will run on either architecture.^[29]

PowerPC-only software is supported with Rosetta, though applications may have 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.^[30] 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.^[31] 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 after Mac OS X 10.5. Such cross-platform capability already existed in Mac OS X's lineage; OpenStep was ported to many architectures, including x86, and Darwin included support for both PowerPC and x86. Apple stated that Mac OS X would not run on Intel-based personal computers aside from its own, but a hacked version of the OS compatible with conventional x86 hardware was developed by the OSx86 community.

On June 8, 2009, Apple announced at its Worldwide Developers Conference that Snow Leopard (version 10.6) would drop support for PowerPC processors and be Intel-only.^[32] However, Rosetta is still available in Snow Leopard; it is not installed by default, but it is available on the installation DVD as an installable add-on and is installed automatically via the Internet when first attempting to run a PowerPC-based application.

On all versions from (and including) Lion, Rosetta is no longer available.

Features[link]

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 anti-aliasing technology.^[33] 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.^[34] 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.^[35] 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.^[34] As a side result, PDF viewing and creating PDF documents from any application are built-in features.^[36]

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.^[37] Also, FileVault was introduced, which is an optional encryption of the user's files with Advanced Encryption Standard (AES-128).^[38]

Features introduced in version 10.4 include Automator, an application designed to create an automatic workflow for different tasks;^[39] Dashboard, a full-screen group of small applications called desktop widgets that can be called up and dismissed in one keystroke;^[40] and Front Row, a media viewer interface accessed by the Apple Remote.^[41] 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.^[42]

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.^[43] 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.^[44] 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;^[45] and Screen Sharing was built in for the first time.^[46]

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.^[47][48] 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.^[49][50] Mac OS X makes use of a Dock, which holds file and folder shortcuts as well as minimized windows.

Versions[link]

With the exception of Mac OS X Server 1.0 and the original public beta, Mac OS X versions are named after big cats. 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", and the current version 10.7 as "Lion". "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.^[59] 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.^[60]

Public Beta: "Kodiak"[link]

On September 13, 2000 Apple released a $29.95^[61] "preview" version of Mac OS X (internally codenamed Kodiak) in order to gain feedback from users.^[62]

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.^[63]

Version 10.0: "Cheetah"[link]

On March 24, 2001, Apple released Mac OS X v10.0 (internally codenamed Cheetah).^[64] 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"[link]

Later that year on September 25, 2001, Mac OS X v10.1 (internally codenamed Puma) was released.^[65] It had better 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.^[66] 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.^[67]

Version 10.2: "Jaguar"[link]

On August 23, 2002,^[68] Apple followed up with Mac OS X v10.2 "Jaguar", the first release to use its code name as part of the branding.^[69] It brought great performance enhancements, a sleeker look, and many powerful enhancements (over 150, according to Apple^[70] ), 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.^[71] 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"[link]

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.^[72] Support for some early G3 computers such as "beige" Power Macs and "WallStreet" PowerBooks was discontinued.

Version 10.4: "Tiger"[link]

Mac OS X v10.4 "Tiger" was released on April 29, 2005. Apple stated that Tiger contained more than 200 new features.^[73] As with Panther, certain older machines were no longer supported; Tiger requires a Mac with a built-in FireWire port.^[25] 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.^[74] Only PowerPC Macs can be booted from retail copies of the Tiger client DVD, but there is a Universal DVD of Tiger Server 10.4.7 (8K1079) that can boot both PowerPC and Intel Macs.

Version 10.5: "Leopard"[link]

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.^[75] 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,^[76] 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.^[77][78] Leopard dropped support for the Classic Environment and all Classic applications.^[79]

It was the final version of Mac OS X to support the PowerPC architecture.

Version 10.6: "Snow Leopard"[link]

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 focuses on "under the hood" changes, increasing the performance, efficiency, and stability of the operating system. For most users, the most noticeable changes are: 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.

The rewrite of Finder in Apple's native Cocoa API allows the Finder to take advantage of the new technologies introduced in Snow Leopard. An update of the web browser, Safari 4, includes a boost in JavaScript and HTML performance, which results in faster web browsing. The majority of this performance boost is enabled by the new SquirrelFish JavaScript interpreter, improving the JavaScript rendering performance of Safari by over 50%.^[80] The new Top Sites also displays the most frequently visited and/or bookmarked sites in a panorama view, allowing the user to easily access their favorite sites along with a new Cover Flow view for the user's browsing history. Safari 4 is now also more crash resistant, being able to isolate plug-ins which are the main cause of web browser crashes.^[81]

Mac OS X v10.6 also features Microsoft Exchange Server support for Mail, iCal, and Address Book, new 64-bit technology capable of supporting greater amounts of RAM, an all new QuickTime X with a refreshed user interface and more functionality that used to be only available to QuickTime Pro owners.

Back-end platform changes include improved support for multi-core processors through Grand Central Dispatch which attempts to ease the development of applications with multi-core support, and thus improve their CPU utilization. It used to be that developers needed to code their programs in such a way that their software would explicitly take advantage of the multiple cores, which could easily become a tedious and troublesome task, especially in complex software. It also includes advanced GPU performance with OpenCL (a cross platform open standard for GPGPU distinct from CUDA, Dx11 Compute Shader or STREAM) by providing support to offload work normally only destined for a CPU to the graphic card's GPU. This can be especially useful in tasks that can be heavily parallelized.

An update introduced support for the Mac App Store, Apple's digital distribution platform for OS X applications.^[82]

Snow Leopard only supports machines with Intel CPUs, requires at least 1 GB of RAM, and drops default support for applications built for the PowerPC architecture (Rosetta can be installed as an additional component to retain support for PowerPC-only applications).^[83]

Version 10.7: "Lion"[link]

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

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.^[84] 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"[link]

OS X v10.8 "Mountain Lion" was announced on February 16, 2012. It will incorporate some features seen in iOS 5. These 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.^[85] It is scheduled to be released in late summer 2012.^[58] 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.^[86]

See also[link]

Apple portal

• A/UX
• 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)

References[link]

External links[link]

• Official website
• Apple's listings of 3rd party software for OS X

v t e Apple Inc. History Outline Founders Steve Jobs Steve Wozniak Ronald Wayne Board of directors Current Bill Campbell Millard Drexler Al Gore Tim Cook (CEO) Andrea Jung Arthur D. Levinson (Chairman) Ronald Sugar Bob Iger Former Jerry York Executives Current Tim Cook Eddy Cue Scott Forstall Jonathan Ive Bob Mansfield Peter Oppenheimer Phil Schiller Bruce Sewell Jeff Williams John Browett Former Ron Johnson Mark Papermaster Bertrand Serlet Sina Tamaddon Hardware products Apple TV iPad Original 2 3rd iPhone Original 3G 3GS 4 4S iPod Classic Nano Shuffle Touch Mac iMac MacBook MacBook Air MacBook Pro Mini Pro Discontinued products Accessories AirPort Thunderbolt Display iPod accessories Mighty Mouse Magic Mouse Magic Trackpad Keyboard Time Capsule Software products Aperture Bento FileMaker Pro Final Cut Studio GarageBand iLife iOS iTunes iWork Logic Studio Mac OS X Server QuickTime Safari Xsan Stores and services Developer AppleCare Apple Specialist Apple Store online App Store Certifications Game Center iAd Genius Bar iBookstore iTunes Store Mac App Store iWork.com MobileMe iCloud One to One ProCare Companies Braeburn Capital FileMaker Inc. Acquisitions Emagic FingerWorks Intrinsity Lala NeXT Nothing Real P.A. Semi Silicon Color Siri Spruce Technologies Related Advertising 1984 Think Different Get a Mac iPods Slogans Design IDg Typography History Community Criticism Litigation Book Category Portal Project Commons Template

Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. (formerly Apple Computer, Inc.) for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface. The original form of what Apple would later name the "Mac OS" was the integral and unnamed system software first introduced in 1984 with the original Macintosh, usually referred to simply as the System software.

Conception[link]

From the beginning, Apple deliberately sought to minimize by design the user's conceptual awareness of the operating system as such. Tasks that on other products required a more explicit working knowledge of an operating system would on a Macintosh be accomplished by intuitive mouse gestures and manipulation of graphical control panels. The intention was that the product would thus be more user-friendly and so more easily mastered. This would differentiate it from devices using other operating environments, such as MS-DOS machines, which were more technically challenging to operate.

The core of the system software was held in ROM, with updates (which would override ROM-resident portions in RAM) typically provided free of charge by Apple dealers on floppy disk. The user's involvement in an upgrade of the operating system was also minimized to running an installer, or simply replacing system files, the simplicity of which again differentiated the product from other offerings.

Versions[link]

Early versions of the Mac OS were compatible only with Motorola 68000-based Macintoshes. As Apple introduced computers with PowerPC hardware, the OS was ported to support this architecture as well. Mac OS 8.1 was the last version that could run on a "68K" processor (the 68040). Mac OS X, which has superseded the "Classic" Mac OS, is compatible with only PowerPC processors from version 10.0 ("Cheetah") to version 10.3 ("Panther"). PowerPC and Intel processors are supported in version 10.4 ("Tiger", Intel only supported after an update) and version 10.5 ("Leopard"). 10.6 and later versions support only Intel processors.^[4]

The early Macintosh operating system initially consisted of two pieces of software, called "System" and "Finder", each with its own version number.^[5] System 7.5.1 was the first to include the Mac OS logo (a variation on the original Happy Mac startup icon), and Mac OS 7.6 was the first to be named "Mac OS".

Before the introduction of the later PowerPC G3-based systems, significant parts of the system were stored in physical ROM on the motherboard. The initial purpose of this was to avoid using up the limited storage of floppy disks on system support, given that the early Macs had no hard disk. (Only one model of Mac was ever actually bootable using the ROM alone, the 1991 Mac Classic model.) This architecture also allowed for a completely graphical OS interface at the lowest level without the need for a text-only console or command-line mode. Boot time errors, such as finding no functioning disk drives, were communicated to the user graphically, usually with an icon or the distinctive Chicago bitmap font and a Chime of Death or a series of beeps. This was in contrast to computers of the time, which displayed such messages in a mono-spaced font on a black background, and required the use of the keyboard, not a mouse, for input. To provide such niceties at a low level, Mac OS depended on core system software in ROM on the motherboard, a fact that later helped to ensure that only Apple computers or licensed clones (with the copyright-protected ROMs from Apple) could run Mac OS.

Mac OS can be divided into two families:

• The Mac OS Classic family, which was based on Apple's own code
• The Mac OS X operating system, developed from Mac OS Classic family, and NeXTSTEP, which was UNIX-based.

"Classic" Mac OS (1984–2001)[link]

The "classic" Mac OS is characterized by its total lack of a command line; it is a completely graphical operating system. Versions of Mac OS up through System 4 only ran one application at a time. Even so, it was noted for its ease of use. Mac OS gained cooperative multitasking with System 5, which ran on the Mac SE and Macintosh II. It was criticized for its very limited memory management, lack of protected memory, and susceptibility to conflicts among operating system "extensions" that provide additional functionality (such as networking) or support for a particular device. Some extensions may not work properly together, or work only when loaded in a particular order. Troubleshooting Mac OS extensions could be a time-consuming process of trial and error.

The Macintosh originally used the Macintosh File System (MFS), a flat file system with only one level of folders. This was quickly replaced in 1985 by the Hierarchical File System (HFS), which had a true directory tree. Both file systems are otherwise compatible.

Most file systems used with DOS, Unix, or other operating systems treat a file as simply a sequence of bytes, requiring an application to know which bytes represent what type of information. By contrast, MFS and HFS give files two different "forks". The data fork contains the same sort of information as other file systems, such as the text of a document or the bitmaps of an image file. The resource fork contains other structured data such as menu definitions, graphics, sounds, or code segments. A file might consist only of resources with an empty data fork, or only a data fork with no resource fork. A word processor file could contain its text in the data fork and styling information in the resource fork, so that an application which doesn’t recognize the styling information can still read the raw text.

On the other hand, these forks would provide a challenge to interoperability with other operating systems: how does one copy a dual-forked file into a different file system, or across a file-transfer system, or embed it into email? In copying or transferring a MacOS file to a non-Mac system, the default implementations would simply strip the file of its resource fork. Most data files contained only nonessential information in their resource fork, such as window size and location, but program files would be inoperative without their resources. This necessitated such encoding schemes as BinHex and MacBinary, which allowed a user to encode a dual-forked file into a single stream, or take a single stream so-encoded and reconstitute it into a dual-forked file usable by MacOS.

PowerPC versions of Mac OS X up to and including Mac OS X v10.4 Tiger (support for Classic was dropped by Apple with v10.5 Leopard's release and it is no longer included) include a compatibility layer for running older Mac applications, the Classic Environment. This runs a full copy of the older Mac OS, version 9.1 or later, in a Mac OS X process. PowerPC-based Macs shipped with Mac OS 9.2 as well as Mac OS X. Mac OS 9.2 had to be installed by the user— it was not installed by default on hardware revisions released after the release of Mac OS X 10.4 Tiger. Most well-written "classic" applications function properly under this environment, but compatibility is only assured if the software was written to be unaware of the actual hardware, and to interact solely with the operating system. The Classic Environment is not available on Intel-based Macintosh systems due to the incompatibility of Mac OS 9 with the x86 hardware.

Users of the classic Mac OS generally upgraded to Mac OS X, but many criticized it as being more difficult and less user-friendly than the original Mac OS, for the lack of certain features that had not been re-implemented in the new OS, or for being slower on the same hardware (especially older hardware), or other, sometimes serious incompatibilities with the older OS.^[6] Because drivers (for printers, scanners, tablets, etc.) written for the older Mac OS are not compatible with Mac OS X, and due to the lack of Mac OS X support for older Apple machines, a significant number of Macintosh users continued using the older classic Mac OS.

In June 2005, Steve Jobs announced at the Worldwide Developers Conference keynote that Apple computers would be transitioning from PowerPC to Intel processors and thus dropping compatibility on new machines for Mac OS Classic. At the same conference, Jobs announced Developer Transition Kits that included beta versions of Apple software including Mac OS X that developers could use to test their applications as they ported them to run on Intel-powered Macs. In January 2006, Apple released the first Macintosh computers with Intel processors, an iMac and the MacBook Pro, and in February 2006, Apple released a Mac mini with an Intel Core Solo and Duo processor. On May 16, 2006, Apple released the MacBook, before completing the Intel transition on August 7 with the Mac Pro. To ease the transition for early buyers of the new machines, Intel-based Macs included an emulation technology called Rosetta, which allows them to run Mac OS X software that was compiled for PowerPC-based Macintoshes. Rosetta runs transparently, creating a user experience identical to running the software on a PowerPC machine, though execution is typically slower than with native code. Rosetta was an optional installation in Mac OS X 10.6 Snow Leopard and is not available at all in Mac OS X 10.7 Lion.

OS X[link]

OS X is the newest of Apple Inc.'s Mac OS line of operating systems. Although it is officially designated as simply "version 10" of the Mac OS, it has a history largely independent of the earlier Mac OS releases.

The operating system is the successor to Mac OS 9 and the "classic" Mac OS. It is a Unix operating system, based on the NeXTSTEP operating system and the Mach kernel which Apple acquired after purchasing NeXT Computer, with its CEO Steve Jobs returning to Apple at this time. Mac OS X also makes use of the BSD code base. There have been six significant releases of the client version, the most recent being Mac OS X 10.7, referred to as Lion. In February 2012, Apple announced OS X 10.8. referred to as Mountain Lion.

As well as the client versions, OS X has also had six significant releases as a server version, called Mac OS X Server. The first of these, Mac OS X Server 1.0, was released in beta in 1999. The server versions are architecturally identical to the client versions, with the differentiation found in their inclusion of tools for server management, including tools for managing Mac OS X-based workgroups, mail servers, and web servers, amongst other tools. It was the default operating system for Xserve (which has now been discontinued),^[7] it's an optional feature on the Mac Mini and the Mac Pro, and it's also installable on most other Macs. Unlike the client version, Mac OS X Server can be run in a virtual machine using emulation software such as Parallels Desktop and VMWare Fusion.

OS X is also the basis for iOS, (previously iPhone OS) used on Apple's iPhone, iPod Touch, and iPad.

Star Trek[link]

Star Trek (as in "to boldly go where no Mac has gone before") was a relatively unknown secret prototype Apple started work on in 1992, which goal was to create a version of the classic Mac OS that would run on Intel-compatible x86 personal computers. The project was instigated by Novell, Inc., who were looking to integrate their DR-DOS with the Mac OS UI as a retort to Microsoft's Windows 3.0. The Apple/Novell team (fourteen engineers from the former, four from the latter) was able to get the Macintosh Finder and some basic applications, like QuickTime, running smoothly on the x86 architecture. Some of the code from this effort was reused later when porting the Mac OS to PowerPC.^[8]

The project was cancelled only one year later in early 1993. There are two theories for the project's short life: the first is that Apple's board canceled further development upon realizing that going with Star Trek would mean an entirely new business model and one that would likely see a notable drop in Apple's lucrative hardware sales; and the second is that an x86 Mac OS was not commercially viable in the early nineties because Microsoft's contracts for Windows 3.1 forced PC manufacturers to pay a royalty to Microsoft for every computer shipped, regardless of what operating system it contained.^[9]

A further complication was that Star Trek was designed to be source-level compatible, not binary compatible, with the Mac OS. Mac applications would therefore have to be recompiled or rewritten by their developers to run on the x86 architecture, and there was much skepticism as to exactly how much work this would entail.

Fifteen years after Star Trek, support for the x86 architecture was officially included in Mac OS, and then Apple transitioned all desktop computers to the x86 architecture. This was not the direct result of earlier Project Star Trek efforts. The Darwin underpinning used for Mac OS X 10.0 and later included support for the x86 architecture. The remaining non-Darwin portion of Mac OS X (based on OPENSTEP, which ran on Intel processors) was released officially with the introduction of x86 Macintosh computers.

68000 emulation[link]

Although the Star Trek software was never released, third-party Macintosh emulators, such as vMac, Basilisk II, and Executor, eventually made it possible to run the classic Mac OS on Intel-based PCs. These emulators were restricted to emulating the 68000 series of processors, and as such most couldn't run versions of the Mac OS that succeeded 8.1, which required PowerPC processors. Most also required a Mac ROM image or a hardware interface supporting a real Mac ROM chip; those requiring an image are of dubious legal standing as the ROM image may infringe on Apple's intellectual property.

A notable exception was the Executor commercial software product from Abacus Research & Development, the only product that used 100% reverse engineered code without the use of Apple technology. It ran extremely quickly but never achieved more than a minor subset of functionality. Few programs were completely compatible and many were extremely crash-prone if they ran at all. Executor filled a niche market for porting 68000 classic Mac applications to x86 platforms; development ceased in 2002 and the source code was released by the author in late 2008.^[10]

Emulators using Mac ROM images offered near complete Mac OS compatibility and later versions offered excellent performance as modern x86 processor performance increased exponentially.

Most of the Mac user base had already started moving to the PowerPC platform that offered backward compatibility on 8.xx & 9.xx operating systems along with faster PowerPC software support. This helped ease the transition to PowerPC-only applications while prematurely obsolescing 68000 emulators and the Classic-only applications they supported well before these emulators were refined enough to compete with a real Mac.

PowerPC emulation[link]

At the time of 68000-emulator development, PowerPC support was difficult to justify not only due to the emulation code itself but also the anticipated wide performance overhead of an emulated PowerPC architecture vs. a real PowerPC based Mac. This would later prove correct with the start of the PearPC project even years later despite the availability of 7th & 8th generation x86 processors employing similar architecture paradigms present in the PowerPC. Many application developers were also creating and releasing both 68000 Classic and PowerPC versions concurrently helping to negate the need for PowerPC emulation. PowerPC Mac users who could technically run either obviously chose the faster PowerPC applications. Soon Apple was no longer selling 68000-based Macs and the existing installed base started to quickly evaporate. Despite the eventual excellent 68000-emulation technology available they proved never to be even a minor threat to real Macs due to their late arrival and immaturity even several years after the release of much more compelling PowerPC based Macs.

The PearPC emulator is capable of emulating the PowerPC processors required by newer versions of the Mac OS (like Mac OS X). Unfortunately, it is still in the early stages and, like many emulators, tends to run much slower than a native operating system would.

During the transition from PowerPC to Intel processors, Apple realized the need to incorporate a PowerPC emulator into Mac OS X in order to protect its customers' investments in software designed to run on the PowerPC. Apple's solution is an emulator called Rosetta. Prior to the announcement of Rosetta, industry observers assumed that any PowerPC emulator running on an x86 processor would suffer a heavy performance penalty (e.g., PearPC's slow performance). Rosetta's relatively minor performance penalty therefore took many by surprise.

Another PowerPC emulator is SheepShaver, which has been around since 1998 for BeOS on the PowerPC platform, but in 2002 was open sourced with porting efforts beginning to get it to run on other platforms. Originally it was not designed for use on x86 platforms and required an actual PowerPC processor present in the machine it was running on similar to a hypervisor. Although it provides PowerPC processor support, it can only run up to Mac OS 9.0.4 because it does not emulate a memory management unit.

Other examples include ShapeShifter (by the same programmer that conceived SheepShaver), Fusion and iFusion. The latter ran classic Mac OS with a PowerPC "coprocessor" accelerator card. Using this method has been said to equal or better the speed of a Macintosh with the same processor, especially with respect to the m68k series due to real Macs running in MMU trap mode, hampering performance.

Macintosh clones[link]

Several computer manufacturers over the years have made Macintosh clones capable of running Mac OS, notably Power Computing, UMAX and Motorola. These machines normally ran various versions of classic Mac OS. Steve Jobs ended the clone-licensing program after returning to Apple in 1997.

In 2008, a manufacturing company in Miami, FL called Psystar Corporation, announced a $499 clone that comes with a barebones system that can run Mac OS X 10.5 Leopard. Threatened with legal battles, Psystar originally called the system OpenMac and have since changed it to Open Computer. Apple filed a lawsuit with the company and asked that Psystar be ordered to stop producing clone systems, recall every system sold, and pay monetary damages.^[11] Eventually, Apple prevailed in court, and the Open Computer's production was ceased. Psystar itself appears to be defunct now, as the company's website is gone.

A/UX[link]

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. A/UX had most of its success in sales to the U.S. government, where UNIX was a requirement that Mac OS could not meet. Mac OS X later incorporated code from the UNIX-based NeXTStep after Steve Jobs rejoined Apple in 1997.

MAE[link]

The Macintosh Application Environment (MAE) was a software package introduced by Apple Computer in 1994 which 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.

MkLinux[link]

Announced at The 1996 World Wide Developers Conference (WWDC), MkLinux is an open source computer operating system started by the OSF Research Institute and Apple Computer in February 1996 to port Linux to the PowerPC platform, and thus Macintosh computers. In the summer of 1998, the community-led MkLinux Developers Association took over development of the operating system. MkLinux is short for "Microkernel Linux," which refers to the project's adaptation of the Linux kernel to run as a server hosted atop the Mach microkernel. MkLinux is based on version 3.0 of Mach.

Mac OS on non Apple-labeled computers[link]

This section relies on references to primary sources or sources affiliated with the subject, rather than references from independent authors and third-party publications. Please add citations from reliable sources. (March 2012)

Although apparently a violation of Apple's EULA,^[12] running Mac OS X operating systems compiled for x86 or x86_64 ("Intel 64") on a non-Apple PC is possible using several approaches. If the processor is an Intel Core 2 or later, but not an Intel Atom, Apple's standard mach_kernel is sufficient.^{[citation needed]} If the processor is an Atom, the user-supported "legacy" mach_kernel_atom, derived from the appropriate mach_kernel, is required.^{[citation needed]} If the processor is a pre-Core 2 Intel, say, a late Pentium 4 either with or without EM64T, but usually with H-T, the user-supported "legacy" mach_kernel_non-atom, derived from the appropriate mach_kernel, is required.^{[citation needed]}

Installation of MacOS X requires a MacOS X Installer emulator, the most straightforward of which is a USB flash drive-type Installer emulator. Once the installation has been successfully completed to the hard drive, the hard drive may be booted using the emulator portion of the USB flash drive as a "helper" and a boot loader Installer may be downloaded and used to place the boot loader on the hard drive's boot blocks. Thereafter, MacOS X may be booted from the hard drive alone; the installed boot loader takes care of any required device injection and/or kernel patching.

MacOS X is generally compatible with any Intel desktop-based system or Intel-based motherboard, ICH6 or later,^[13] however compatibility past Snow Leopard cannot be assured with ICH6. Compatibility with ICH7 and with Lion and 945 (G)MCH has already been demonstrated and proved. Compatibility with ICH7 or later and any associated MCH/(G)MCH is quite good, certainly including Lion, and possibly also including Mountain Lion.

MacOS X compatibility with Intel laptop- or netbook-based systems is quite variable but has been successful on a few Intel Atom-based netbooks.

References[link]

Bibliography[link]

• Hormby, Tom (2005) "Star Trek: Apple's First Mac OS on Intel Project"

External links[link]

• Mac OS X – Official site
• Mac 101 – Apple's introductory guide to the Mac OS.
• Folklore.org – A site of anecdotes shared by the creators of the first Macintosh.
• The Vintage Mac Museum: – Old Mac System - From System1 to System7