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Mac OS X, the latest version of the Mac OS, is an operating system for Macintosh computers from Apple that combines
popular features of the traditional Macintosh user interface on top of
a stable Unix operating environment. The pronunciation OS ten is favored by Apple,
to stress continuity with previous Macintosh operating systems (which were named e.g. "OS 9"). Others say OS ex, to
emphasize the relationship with Unix, because of the presence of the roman
numeral X in the name of the operating system, or because Apple often uses "Mac OS X v10.4" or variants thereof.
Mac OS X was created by combining Darwin, an open source Unix-like environment, which is based on the
BSD source tree and the Mach microkernel, with a GUI, called Aqua, developed by Apple Computer. The operating system saw its first commercial release in 2001.
History
Main article: Mac OS X history
What is today 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,
saying that high prices accompany high quality, though many were not willing to take the NeXT route, beneficial or not. 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 in time, 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—however 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, was
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.
Description
Screenshot of Mac OS X 10.3
Many of Mac OS X's users consider its Aqua GUI to be the most attractive and functional in existence. It has been imitated by
many others; there are Aqua lookalikes for other operating systems, (e.g., mosfet liquid). Interfaces 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.
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. Apple's X11 will
make it even easier to exchange packages with UNIX and Linux users.
Notable interface features
- "Uses the Portable Document Format (PDF) as the
basis of its imaging model." (Quartz)
- OpenGL is used to composite windows onto the screen to improve performance
- Full color, continuously scalable icons (up to 128x128 pixels)
- Drop shadow around window and isolated text elements to provide a sense of depth
- Global spell checking and other powerful tools thanks to NeXT style application
services
- Anti-aliasing of widgets, text, and window elements
- New interface elements including sheets (non-modal dialogues attached to specific windows) and drawers.
- Interweaving windows (i.e. an application's windows are not necessarily adjacent in the visible stacking order)
- Industrial strength color matching (ColorSync ) built
in to the core drawing engine (for print and multimedia professionals)
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). 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 new
features as Jaguar did.
Contrary to 10.1, both Jaguar and Panther were paid releases.
Codenames
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, Cougar, Leopard, and
Tiger.
Versions
Detailed MacOS timeline and MacOS X Build Numbers
Software
Main article: List of Macintosh
software
Press release
Information on Mac OS X, courtesy of Apple Computer's press
relations:
- ...combines the power and stability of UNIX with the simplicity and elegance of the
Macintosh.
- ...innovative time-saving features including a new Finder and the Dock designed to help you navigate and organize your
system, and give you instant access to your most frequently used applications, folders...
- ...built on three cutting-edge graphics technologies Quartz, OpenGL, and QuickTime...
- ...the foundation of Mac OS X [is] an industrial-strength, UNIX-based core operating system—called
Darwin—that delivers unprecedented stability and performance...powerful, advanced features such as protected memory, preemptive multitasking, advanced memory management, and symmetric multiprocessing...
- ...Seamless device connectivity and industry-leading applications...
- ...includes powerful, easy-to-use tools for making your own movies, managing your music, and capturing photos from your
digital camera. Built-in support for burning music and data CDs, playing DVD movies, and even
authoring your own DVDs...
- ...lets you run thousands of existing Mac OS 9-compatible applications, while... Mac OS X provide[s] a foundation for
great new applications.
External links
Apple Computer
Other links
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