Mac OS X history
The Mac OS X is the most recent 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. This model is also called the «Snow Leopard» as the older version was the ‘Lion».
Development Outside of Apple
When Apple fired Steve Jobs in 1985, he attempted — with funding from Ross Perot and his own pockets — to create the «next big thing»: the result was NeXT. NeXT hardware, while somewhat innovative for its time, was more expensive in relation to the rapidly commoditising workstation market, had several design problems and quirks which made it unpopular, and was phased out in 1993. The object-oriented operating system NeXTSTEP, on the other hand, had a more lasting legacy. It was based on on the Mach kernel and BSD, an open source implementation of UNIX dating back to the 1970s, and included the innovative Enterprise Objects Framework database access layer and WebObjects application server development environment. NeXT managed to maintain a business selling WebObjects and consulting services, but was never a commercial success. NeXTSTEP underwent an evolution into OPENSTEP which separated the object layers from the operating system below, allowing it to run with less modification on other platforms. However, by this point, a number of other companies—notably Apple, IBM, and Microsoft—were claiming they would soon be releasing similar object-oriented operating systems and development tools of their own. (Some of these efforts, such as Taligent, did not fully come to fruition.)
Internal Development
Meanwhile, Apple was in fact having commercial difficulties as well. The decade-old Mac OS had reached the limits of its single-user, co-operative multitasking architecture, and its once-innovative user interface was looking increasingly «dated» next to the rapidly-evolving Microsoft Windows. A massive development effort to replace it, known as Copland, was started in 1994, but was generally perceived outside of Apple to be a hopeless case due to political infighting. By 1996 Copland was nowhere near ready for release, and the effort was eventually cancelled outright. Some elements of Copland were incorporated in Mac OS 8, released in 1997.
After considering the purchase of BeOS — a multimedia-enabled multi-tasking OS designed for hardware similar to Apple’s — the company decided instead to acquire NeXT and use OPENSTEP as the basis for their new OS. Avie Tevanian took over OS development and Steve Jobs was brought on as a consultant. At first the plan was to develop a new operating system based almost entirely on an updated version of OpenStep, with an emulator — known as the Blue Box — for running «classic» Macintosh applications. The result was known under the code name Rhapsody, slated for release in late 1998.
Apple expected that developers would port their software to the considerably more powerful OpenStep libraries once they learned of its power and flexibility. Instead, the vast majority of developers told Apple that this would never occur, and that they would rather leave the platform entirely. This «rejection» of Apple’s plan was largely the result of a string of previous broken promises from Apple; after watching one «next OS» after another disappear and Apple’s marketshare dwindle, developers were not interested in doing much work on the platform at all, let alone a re-write.
Changed Direction Under Jobs
Apple’s financial losses continued, and eventually Jobs persuaded the board of directors to fire CEO Gil Amelio and appoint him Chairman and interim CEO. Jobs was, in essence, given carte blanche by the Apple board to return the company to profitability. When Jobs announced at the Worldwide Developers Conference that what developers really wanted was a modern version of the Mac OS, and that’s what they were going to deliver, this was met with thunderous applause. Over the next two years major effort was applied to re-writing the original Macintosh APIs as Unix libraries known as Carbon. Mac OS applications could be ported to Carbon without the need for a re-write, while still making them full citizens of the new operating system. Meanwhile, applications written using the older toolkits would be supported using the «Classic» Mac OS 9 emulator. Including support for the use of C, C++, Objective C, Java, and Python furthered developer comfort.
During this time the lower layers of the operating system (the Mach kernel and the BSD layers on top of it), were re-packaged and released under an open source license as Darwin. The Darwin kernel provides an extremely stable and flexible operating system which rivals many other Unix implementations, and takes advantage of the contributions of programmers and independent open-source projects outside of Apple; however it is unclear if it sees any real use outside the Macintosh community. During this period the Java programming language became the «hot topic» in the programming world, and an effort was started to make the Mac the best Java platform. This consisted of both porting an excellent high-speed Java system to the platform, as well as exposing OS-X-specific «Cocoa» APIs to the Java language. The resulting changes delayed the introduction of the operating system by about two years.
While the first release of the new OS — Mac OS X Server 1.0 — used a modified version of the Mac OS GUI, Mac OS X Public Beta and later used a new GUI known as Aqua. The development of this part of the OS was delayed somewhat by the switch from OpenStep’s Display PostScript engine to one that was license free, known as Quartz. Aqua was a fairly radical departure from the Mac OS 9 interface, which had been essentially just an improved color version of the Finder version 1.0 shipped with the original Macintosh. It incorporated such «eye candy» as full colour scalable graphics, anti-aliasing of text and graphics, simulated shading and highlights, transparency and shadows, and animation. A key new feature was the Dock, an application launcher which took full advantage of these capabilities. But it maintained a substantial degree of compatibility with the traditional Mac OS interface and Apple’s own human interface guidelines, with its pull-down menu at the top of the screen, familiar keyboard shortcuts, and support for a single-button mouse.
Development of Mac OS X
Apple released Mac OS X Server 1.0, in January 1999. A public beta of Mac OS X was released in 2000 and March 24, 2001, saw the full and official release of Mac OS X version 10.0. Version 10.1 shipped around September 26, 2001, followed by the August 24, 2002 release of Mac OS X 10.2 («Jaguar») and the October 24, 2003 release of Mac OS X 10.3 («Panther»). In June 2004, Jobs announced that version 10.4 («Tiger») would be released in the first half of 2005.
Mac OS X 10.0
Apple shipped Mac OS X 10.0 «Cheetah» on March 24, 2001. The first version was somewhat lacking, with incomplete support for CD burning and the usage of DVDs.
Mac OS X 10.1
Apple shipped Mac OS X 10.1 «Puma» on September 26, 2001. This new version was what many dubbed the «first really usable version» of Mac OS X. Amongst the major changes: major speedbumps, support for many peripherals, and major debugging, as well as the addition of new features and the optimisation of existing features.
Mac OS X 10.2
Mac OS X 10.2 «Jaguar» was shipped on August 24, 2002. It included the wildly popular iChat, as well as numerous new features.
Mac OS X 10.3
Apple shipped Mac OS X 10.3 «Panther» on October 24, 2003. Mac OS X 10.3 «Panther» included an AV-ready version of iChat (iChat AV), a completely new Finder window interface (including near-live search and a sidebar), and an enhanced Preview application.
Mac OS X 10.4
Apple shipped Mac OS X 10.4 «Tiger» on April 29, 2005. In this new version, Spotlight, Automator, Dashboard and the new Mail application made for some of the most important — and the most welcome — additions to the new system.
Mac OS X 10.5
Apple shipped Mac OS X 10.5 «Leopard» on October 26, 2007.
Mac OS X 10.6
Apple shipped Mac OS X 10.6 «Snow Leopard» on August 28, 2009.
Mac OS X 10.7
Apple shipped Mac OS X 10.7 «Lion» on July 20, 2011.
Mac OS X 10.8
Apple shipped Mac OS X 10.8 «Mountain Lion» on July 25, 2012
Mac OS X 10.9
Apple shipped Mac OS X 10.9 «Mavericks» on October 22, 2013.
Mac OS X 10.10
Apple shipped OS X 10.10 «Yosemite» on October 16, 2014.
History of macOS
macOS is the operating system used by Apple Macintosh computers. Here we examine History of macOS, from beginnings to now.
Pre-System 5
Macintosh System Software 1
System Software 2
All of these versions could only run one application at a time, though special application shells such as Switcher (discussed under MultiFinder) could get around this to some extent. System 3.0 introduced HFS (Hierarchical File System) which had real directories — previously the Finder created the illusion of folders on the flat file system.
The other significant change that System 4.x brought to the Mac was Colour QuickDraw, which debuted with the Macintosh II in 1986. This significantly altered the extent and design of the underlying graphics architecture (and its APIs), but it is a credit to Apple that most users, and perhaps more importantly existing code, were largely unaware of this.
System 5
«System 5» refers to the system software bundle version, not the System software version. It included System 4.2 and System 4.3. System Software 5.0 added MultiFinder, an add-on replacement for the Finder which could run several programs at once. Time was given to the background applications only when the foreground (or «running») applications gave it up (cooperative multitasking), but in fact most of them did via a clever change on the OS’s event handling. The others significant change that System Software 5 brought to the Mac was Color QuickDraw, which debuted with the Macintosh II. This significantly altered the extent and design of the underlying graphics architecture (and its APIs), but it is a credit to Apple that most users, and perhaps more importantly existing code, were largely unaware of this.
System 5 was also the first Macintosh operating system to be given a unified «Macintosh System Software» version number, as opposed to the numbers used for the System and Finder files.
- System Software 5.0 (System 4.2, Finder 6.0, MultiFinder 1.0)
- System Software 5.1 (System 4.3, Finder 6.0, MultiFinder 1.0)
System 6
System 6 added MultiFinder, an add-on replacement for the Finder which could run several programs at once. Time was given to the background applications only when the foreground (or «running») applications gave it up (cooperative multitasking), but in fact most of them did via a clever change on the OS’s event handling. MultiFinder had been released with earlier systems, but the 6.x systems were the first to make it official and widely used.
System 6 consolidated the previous releases into a much more complete and stable operating system. It also moved the Mac to true 32-bit memory addressing — necessary with the ever increasing amounts of RAM available. Earlier systems used the lower 24 bits for addressing, and the upper 8 bits for flags. This was a neat solution on the earlier Macs with their very limited amounts of RAM, but became a liability later. Code that assumed the 24 + 8 bit addressing was «not 32-bit clean» in Apple’s words, and developers were required to excise such assumptions from their code.
System 7
System 7 was a major upgrade to the Mac OS, but the core of the OS remained the same as in prior versions. Instead the new 7.x OS’s included a huge number of «high level» additions, considered by some observers to be less well thought out than they might have been.
Although the name was changed to 8.x and 9.x over its history, the OS remained basically the same internally.
«System» designation
Performa Systems
«Mac OS» designation
Mac OS 8
Mac OS 8.x was very much a stop-gap version which was brought out to try and keep the Mac OS moving forward during a very trying time for the platform. 8.0 added a number of features from the stillborn Copland project, while leaving the underlying operating system unchanged. The GUI was changed in appearance to a new greyscale look, and the ability to change the appearance (a.k.a «skins») was added with a new control panel. This was provided by a new «appearance» API layer within the OS, one of the few significant changes. Mac OS 8 also saw the introduction of an updated version of HFS, HFS+, which fixed many of the limitations of the earlier system — in fact it is still in use today on Mac OS X. There were some other interface changes such as separating network features from printing (the venerable, and rather odd Chooser was at last headed for retirement), and some improvements to application switching. However, in most significant respects, System 8 was not very different from System 7.x.
Mac OS 9
Mac OS 9.x was a steady evolution from Mac OS 8. In fact the only reason that the version got increased from 8 to 9 was to pave the way to the future OS X («ten»), rather than leave a gap in the version numbers which might have discouraged some to make the eventual change to OS X. 9 also added some transitional technologies to help application developers adopt some OS X features sooner rather than later, again easing the transition. These included new APIs for the file system, and the bundling of the Carbon library that apps could link against instead of the traditional API libraries — apps that were adapted to do this can be run natively on OS X as well. Other changes were made in OS 9 to allow it to be booted in the «classic environment» within OS X. This is a compatibility layer in OS X (in fact an OS X application, known in developer circles as «the blue box») that runs a complete Mac OS 9 operating system, so allowing applications that have not been ported to Carbon to run on Mac OS X. This is reasonably seamless, though «classic» applications retain their original OS 8/9 appearance and do not gain the OS X «Aqua» appearance.
Mac OS X
Mac OS X is the first real replacement for the older Mac OS, based on the OPENSTEP Unix operating system from NeXT. In addition to the original OPENSTEP libraries, OS X adds the Carbon libraries to allow older programming paradigms from the System 7.x core to be run under OS X and gain many of the benefits of this modern OS core. The system also includes Classic, a complete emulator for running older Mac programs.