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Mac OS X is the latest version of the Mac OS operating system for Macintosh computers. Developed and published by Apple Computer, it provides the stability of a Unix operating environment and adds popular features of the traditional Macintosh user interface. The operating system was first commercially released in 2001.
The pronunciation of X as ten is favored by Apple, to emphasize continuity with previous Macintosh operating systems such as Mac OS 9. Some people pronounce it ex because of the presence of the roman numeral X in the name of the operating system, or to emphasize the relationship with Unix, or because Apple often refers to specific versions as "Mac OS X 10.4" or variants thereof.
Mac OS X consists of two parts: Darwin, an open source Unix-like environment which is based on the BSD source tree and the Mach microkernel, and a proprietary GUI named Aqua, developed by Apple Computer.
A server version of Mac OS X, named Mac OS X Server, is available. It is identical to the regular version except for the inclusion of tools to run various network services on a computer, such as a mail server, a Samba server, a directory server, and a domain name server.
Main article: Mac OS X history
Today's Mac OS X originally started in 1989 as NeXTSTEP, the object-oriented operating system developed by Steve Jobs' NeXT company after he was forced from Apple in 1986. After disappointing sales of the computers designed to run it, NeXTSTEP was ported to a number of other platforms in the early 1990s, but never became very popular because of the arguably high pricing that NeXT applied to its products, especially for its development tools. NeXT had justified this by saying that high prices accompany high quality; still, many were not willing to take the NeXT route. NeXTSTEP then 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.)
Coincident with these developments, by the mid-1990s Apple's own operating system had reached the limits of its single-user, co-operative multitasking architecture. A massive development effort to replace it, known as Copland, was started in 1994, but was generally realized 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.
At this point the new CEO of Apple turned to the market to look for a replacement - a modern operating system with the UI Apple users expected, and the performance and modern features needed to move the platform forward. After some time, and a publicly rancorous debate, OpenStep was selected as the basis and Apple purchased NeXT outright.
At first the plan was to develop a new operating system based almost entirely on an updated version of OpenStep, with an emulator for running "classic" Macintosh applications known as the Blue Box. The result was known under the code name Rhapsody, slated for release in late 1998.
It was expected that developers would port their software to the considerably more powerful OpenStep libraries once they learned of its power and flexibility. Instead, perhaps unexpectedly, 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; after watching one new 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.
The plans were changed at the 1999 World Wide Developer's Conference, when Steve Jobs announced that what developers really wanted was a modern version of the MacOS, 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. MacOS applications could be ported to Carbon without the need for a re-write, while still making them first-class citizens of the new operating system. (see Carbon (computing))
During this time the lower layers of the operating system, consisting of the Mach kernel and the BSD layers on top, 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, however it is unclear if it sees any real use outside the Macintosh community. Another change was required by the switch from OpenStep's Display PostScript engine to one that was license free, known as Quartz. Finally, during this period the Java programming language became the "hot topic" in the programming world, 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 Cocoa APIs to the Java language. The resulting changes delayed the introduction of the operating system by about two years.
Many of Mac OS X's users consider its Aqua GUI to be the most attractive and functional in existence (though many older Macintosh users found the new interface to be "toy-like" and lacking in professional polish). It has been imitated by many others; there are Aqua lookalikes for other operating systems. In addition, interface skins imitating the Aqua look exist for many Microsoft Windows programs, such as Winamp.
This combination of GUI and kernel has recently become the most popular-selling Unix environment to date by sheer numbers.
(Note that Mac OS X is not officially a Unix OS, as Apple has not sought The Open Group branding, claiming that the cost of certification would make the OS prohibitively expensive. The Open Group has sued Apple over alleged violation of the UNIX trademark and has stated that the maximum fee required to certify OS X as a UNIX would be US$110,000 total.)
Mac OS X is compatible with older Mac OS applications by using Classic, an application which allows users to run Mac OS 9.x within Mac OS X, so that most older applications, such as the ubiquitous SimpleText, etc., run as they would under Mac OS 9.x. In addition, the Carbon APIs were added to permit legacy code to be quickly ported to run natively on both Mac OS X and Mac OS 9.x. A fourth option for developers is to write applications in the Java platform, which OS X supports. The NEXTStep/OpenStep APIs are still available, but Apple now calls the technology Cocoa. You can see the NEXTStep heritage in the Cocoa APIs by the fact that class names mostly begin with "NS" (for NEXTStep).
Mac OS X can run many BSD or Linux software packages once compiled for the platform. Compiled binaries are normally distributed as Mac OS X Packages; but may still require command-line configuration or compilation. Projects like Fink and DarwinPorts provide precompiled or preformatted packages for many standard packages.
Version 10.3 was the first to include Apple X11, Apple's version of the X11 graphical interface for Unix applications, as an optional component during install. Apple's implementation is based on XFree86 4.3 and X11R6.6, with its own window manager which mimics the native look, closer integration with Mac OS X and extensions to use the native Quartz rendering system and accelerate OpenGL.
On March 24 2001, Apple released Mac OS X version 10.0. It was praised for its completeness and stability at such an early point in its development (it being a total departure from previous Apple releases). Despite this, it was criticized for being slow, leading many (including Steve Jobs) to consider it an excellent beta release. In September of that year, version 10.1 was released as a free update, increasing the speed and performance of the system as well as providing missing features, such as DVD playback.
In 2002, Apple followed up with Jaguar, Mac OS X 10.2, which brought profound performance enhancements, a newer, sleeker look, and many powerful enhancements (over 150, according to Apple). From the time of release of 10.2, Mac OS X is now the only system shipping on new Macintosh computers.
Mac OS X 10.3, Panther, was released on October 24, 2003, and in addition to providing much improved performance also incorporated the most extensive update to the user interface, Aqua. The update included as many or more as Jaguar did.
Mac OS X 10.4, Tiger, is due to be released in the first half of 2005. Tiger will contain another 150 or more features, including new 64-bit enhancements for the G5.
10.1 was the only free major update. Jaguar and Panther both required purchase, as will Tiger.
All the codenames of OS X versions are named after large felines. Version 10.0 was codenamed Cheetah, 10.1 was codenamed Puma, 10.2 was codenamed Jaguar (which Steve Jobs pronounced "jag-wire"), and 10.3 was codenamed Panther. 10.4, scheduled for release in the first half of 2005, is codenamed Tiger. Starting with Jaguar, Apple has been using Mac OS codenames as official names. In January 2003, Apple registered the trademarks Lynx (not yet used), Cougar (not yet used), Leopard (not yet used), and Tiger (due to be released H1 2005).
Detailed and
Main article: List of Macintosh software
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