Wikipedia

MacOS

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Mac OS X is an operating system for Macintosh computers 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. Others say OS 'ex' to emphasise the relationship with Unix and probably mostly because of the presence of the letter X in the name of the operating system.

OS X was created by combining Darwin, an open source UNIX kernel based environment, which is based on the BSD source tree and the Mach microkernel, with a GUI, called Aqua, made by Apple Computer. It was first released in 2001.

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 it required the wholescale replacement of the machine's natural operating system. NeXTSTEP then underwent an evolution into OPENSTEP, which in theory 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 that they would soon be releasing similar software of their own.

Coincident with these developments, by the mid-1990s Apple's own operating system had reached the limits of its single-user, single-task architecture. A massive development effort to replace it, known as System 8, was started in 1994, but was generally realized outside of Apple to be a hopeless case due to political infighting. By 1996 System 8 was nowhere near ready for release, and the effort was eventually cancelled outright.

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 publically 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 OPENSTEP, with an emulator for running "classic" Macintosh applications. The result was known under the code name Rhapsody, slated for release in 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.

Another re-design was then started, this time promoting the original Macintosh APIs, re-written as Unix libraries, as first-class citizens of the new operating system. Another change was required by the switch from OPENSTEP's Display PostScript engine to one that was license-free, known as Quartz. The resulting changes delayed the introduction of the operating system by about two years.

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.

Description

Mac OS X 10.2 Jaguar screenshot thumbnail
Mac OS X 10.2 Jaguar screenshot thumbnail
Larger version

Many of OS X's users consider its Aqua GUI to be the most attractive and functional in existence, which has been imitated by others; there are Aqua lookalikes for other operating systems, (e.g., mosfet liquid). Interface skins imitating the Aqua look exist for many Microsoft Windows programs, such as Winamp.

This combination of GUI and kernel has very 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, as the cost of certification would make the OS prohibitively expensive.)

OS X is compatible with older Mac OS applications by using Classic, an application which allows users to run Mac OS 9.x within 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 OS X and Mac OS 9.x. A fourth option for developers is to write applications for the Java platform, which OS X supports.

OS X can run many BSD or Linux software packages once compiled for the platform. Compiled binaries are normally distributed as 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 Extreme)
  • 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)

In 2001, Apple released Mac OS X version 10.1, which brought OS X to the public awareness. 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 criticised for being slow, leading many (including Steve Jobs) to consider it an excellent beta release.

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.

In 2003, Steve Jobs confirmed at Apple's Worldwide Developers Conference (WWDC) that development of Jaguar was over and being replaced by Panther, the 10.3 version of Mac OS X which was previewed at WWDC. Panther will be released by the end of the year 2003.

Versions

  • Mac OS X 10.0
  • Mac OS X 10.1, codenamed "Puma"
  • Mac OS X 10.2, codenamed "Jaguar", introduced many new features:
    • Increased support for Windows networks
    • Quartz Extreme for compositing graphics directly on the video card
    • An adaptive spam mail filter
    • A system-wide repository for contact information in the new Address Book
    • Apple Rendezvous networking
    • iChat, an Apple-branded, officially-supported third party AOL Instant Messenger client
    • A revamped Finder with searching built directly into every window
    • Dozens of new universal access features
    • Sherlock 3: Web services (See Watson)
  • Mac OS X 10.3 -- codenamed "Panther"

Press Release

Here, courtesy Apple Computer's press relations, is information on OS X (wikified):

...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.

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