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On January 24, 1984, Apple Computer Inc. (now Apple Inc.) introduced the Macintosh personal computer, with the Macintosh 128K model, which came bundled with what was later renamed the Mac OS operating system, but then known simply as the System Software.^[1] The Macintosh is often credited with popularizing the graphical user interface. The Mac OS has been pre-installed on almost every Macintosh computer sold. The operating system is also sold separately at Apple retail stores, and online. The original Macintosh system software was partially based on the Lisa OS, previously released by Apple for the Lisa computer in 1983 and, as part of an agreement allowing Xerox to buy shares in Apple at a favorable rate, it also used concepts from the Xerox PARC Xerox Alto, which Steve Jobs and several other Macintosh team members had previewed.

Early history

Development

The Macintosh project started in early 1979 with Jef Raskin, who envisioned an easy-to-use, low-cost computer for the average consumer. In September 1979, Raskin began looking for an engineer who could put together a prototype. Bill Atkinson, a member of the Apple Lisa team, introduced him to Burrell Smith, a service technician who had been hired earlier that year.^{[citation needed]}

In January 1981, Steve Jobs completely took over the Macintosh project. Jobs and a number of Apple engineers visited Xerox PARC in December 1979, three months after the Lisa and Macintosh projects had begun. After hearing about the pioneering GUI technology being developed at Xerox PARC from former Xerox employees like Raskin, Jobs negotiated a visit to see the Xerox Alto computer and Smalltalk development tools in exchange for Apple stock options.^[2] The final Lisa and Macintosh operating systems mostly used concepts from the Xerox Alto, but many elements of the graphical user interface were created by Apple including the menubar, pop-up menus and the concepts of drag and drop and direct manipulation.^[3]

Unlike the IBM PC, which used 8 kB of system ROM for power-on self-test (POST) and basic input/output system (BIOS), the Mac ROM was significantly larger (64 kB) and held key OS code. Much of the original Mac ROM was coded by Andy Hertzfeld, a member of the original Macintosh team. He was able to conserve some of the precious ROM space by interleaving some of the assembly language code. In addition to coding the ROM, he also coded the kernel, the Macintosh Toolbox and some of the desktop accessories (DAs) as well. The icons of the operating system, which represented folders and application software were designed by Susan Kare, who later designed the icons for Microsoft Windows 3.0. Bruce Horn and Steve Capps wrote the Macintosh Finder as well as a number of Macintosh system utilities.

Apple was very strong in advertising their newfound machine. After it was created, the company bought all 39 pages of advertisement space in the Newsweek magazine, 1984 November/December edition. Apple was so successful in its marketing for the Macintosh, that it quickly outshone its more sophisticated predecessor, the Lisa, in sales — so much so that Apple quickly developed a product called MacWorks which allowed the Lisa to emulate Macintosh system software through System 3, by which time it had been discontinued as the re-branded Macintosh XL. Many of Lisa's operating system advances would not appear in the operating system until System 7.

Release

The first version of the Mac OS (simply called System) is easily distinguished between other operating systems from the same period because it does not use a command line interface; it was one of the first operating systems to use an entirely graphical user interface. Additional to the system kernel is the Finder, an application used for file management, which also displays the Desktop. The two files were contained in a folder directory labeled System Folder, which contained other resource files, like a printer driver, needed to interact with the System.

System 1, 2, 3 and 4

These releases could only run one application at a time, though special application shells such as Servant^[4], MultiMac^[5], or Switcher (discussed under MultiFinder) could work around this to some extent. System 1.0, 1.1, and 2.0 used a flat file system with only one kludged level of folders, called Macintosh File System (MFS); its support for folders (subdirectories) was incomplete. System 2.0 added support for AppleTalk and the newly introduced LaserWriter to use it. System 2.1 (Finder 5.0) introduced the HFS (Hierarchical File System) which had real directories. This version was specifically to support the Hard Disk 20 and only implemented HFS in RAM, startup and most floppy disks remained MFS 400 K volumes. System 3.0 was introduced with the Mac Plus, officially implementing HFS and 800K startup drives and adding support for several new technologies including SCSI and AppleShare and introducing Trash "bulging" (i.e., when the Trash contained files, it would gain a bulged appearance). System 4.0 came with the Mac SE and Macintosh II, which required additional support for the first expansion slots, the Apple Desktop Bus (ADB), internal hard drives and on the Mac II, color, larger displays and the first Motorola 68020 processor.^[6]

Changes in early Macintosh operating systems are best reflected in the version number of the Finder, where major leaps are found between 1.x, 4.x, 5.x, and 6.x.

System Software Release^[7]	System Version^[7]	Release Date^[7]	Finder Version^[7]	LaserWriter Version^[7]	Release Information^[7]
Mac System Software	1.0 (.97)^[8]	January 24^{[citation needed]}, 1984	1.0		Initial Release
Mac System Software (0.1)	1.1^{[citation needed]}	May 5^{[citation needed]}, 1984	1.1g		Maintenance Release, Added Mountain scene, About box, Clean Up Command
Mac System Software (0.3 & 0.5)	2.0	April 1985^[9]	4.1		Finder Update
System software^[8] ^[10] ^[11]	2.1^[8]	September 1985^[8]	5.0^[10]^[11]		Release for Hard Disk 20 support^[8]^[10]^[11]
Mac System Software (0.7)	3.0	January 1986^{[citation needed]}	5.1	1.1^{[citation needed]}	Introduced with Mac Plus^{[citation needed]}
System Software 1.0	3.1	February 1986^{[citation needed]}	5.2	1.1
System Software 1.1	3.2	June 1986^[12]	5.3	3.1	Fixed problems with data loss, system crashes; updated Chooser and Calculator.^[12]
System Software 2.0	3.3	January 1987	5.4	3.1	Release for Macintosh II and SE
System software^[13]	3.4^[13]		6.1^[13]		Release for Macintosh 512Ke AppleShare 2.0 support^[13]
System Software 2.01	4.0	March 1987^{[citation needed]}	5.4	3.3	Introduced AppleShare^{[citation needed]}
System Software 2.01	4.1	April 1987^{[citation needed]}	5.5	4.0	Maintenance Release of System Software. Updated LaserWriter Driver

System Software 5

System Software 5 (also referred to as simply System 5) added MultiFinder, an extension which let the system run several programs at once. The system used a co-operative multitasking model, meaning that time was given to the background applications only when the running application yielded control. A clever change in system functions that applications were already calling to handle events made many existing applications share time automatically. Users could also choose to not use MultiFinder, and thus stick with using a single application at a time as in previous releases of the system software.

System Software 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 was available for a very short time and only in some countries, including the United States, Canada and some European countries.

System Software Release^[7]	System Version^[7]	Release Date^[7]	Finder Version^[7]	MultiFinder Version^[7]	LaserWriter Version^[7]	Release Information^[7]
5.0	4.2	October 1987^[14]	6.0	1.0	5.0	Initial Release
5.1	4.3	1988 circa	6.0	1.0	5.1	Updated LaserWriter Driver and new version of Apple HD SC Setup

System Software 6

System Software 6 (also referred to simply as System 6) was a consolidation release of the Mac OS, producing a complete, stable, and long-lasting operating system. Two major hardware introductions requiring additional support under System 6 were the 68030 processor and 1.44 MB SuperDrive debuting with the Macintosh IIx and Macintosh SE/30. Later, it would include support for the first specialized laptop features with the introduction of the Macintosh Portable. From System 6 forward, the Finder would have a unified version number closely matching that of the System, alleviating much of the confusion caused by the often considerable differences between earlier Systems.^[15]

System Version^[7]	Release Date^[7]	Finder Version^[7]	MultiFinder Version^[7]	LaserWriter Version^[7]	Release Information^[7]
6.0	April, 1988^{[citation needed]}	6.1	6.0	5.2	Initial Release
6.0.1	September 19, 1988^{[citation needed]}	6.1.1	6.0.1	5.2	Release for Macintosh IIx (1988)
6.0.2	Late 1988^{[citation needed]}	6.1	6.0.1	5.2	Maintenance Release
6.0.3	March 7, 1989^{[citation needed]}	6.1	6.0.3	5.2	Release for Macintosh IIcx (1989)
6.0.4	September 20, 1989^{[citation needed]}	6.1.4	6.0.4	5.2	Release for Macintosh Portable and IIci (1989)
6.0.5	March 19, 1990^[16]	6.1.5	6.0.5	5.2	Release for Macintosh IIfx (1990)
6.0.6	October 15, 1990^{[citation needed]}	6.1.6	6.0.6	5.2	Not released because of AppleTalk bug ^[17]
6.0.7	October 16, 1990^{[citation needed]}	6.1.7	6.0.7	5.2	Official release for Macintosh LC, IIsi and Classic (1990)
6.0.8	April, 1991^{[citation needed]}	6.1.8	6.0.8	7.0	Updated printing software to match software of System 7.0
6.0.8L	Late 1991/Early 1992^{[citation needed]}	6.1.8	6.0.8	7.0	Limited maintenance release for Pacific customers

System 7

On May 13, 1991, System 7 was released. It was a major upgrade to the Mac OS, adding a significant user interface overhaul, new applications, stability improvements and many new features. Its introduction coincided with the release of and provided support for the 68040 Macintosh line.

Perhaps the most significant feature of System 7 was virtual memory support, which previously had only been available as a third-party add-on.^{[citation needed]} Accompanying this was a move to 32-bit memory addressing, necessary for the ever-increasing amounts of RAM available to the Motorola 68030 CPU. This process involved making all of the routines in OS code use the full 32-bits of a pointer as an address — prior systems used the upper 8 bits as flags. This change was known as being "32-bit clean". While System 7 itself was 32-bit clean, many existing machines and thousands of applications were not, so it was some time before the process was completed. To ease the transition, the "Memory" control panel contained a switch to disable this feature, allowing for compatibility with older applications.

One notable System 7 feature was built-in co-operative multitasking. In System Software 6, this function was optional through the MultiFinder. System 7 also introduced aliases, similar to shortcuts that were introduced in later versions of Microsoft Windows. System extensions were enhanced by being moved to their own subfolder; a subfolder in the System Folder was also created for the control panels. In System 7.5, Apple included the Extensions Manager, a previously third-party program which simplified the process of enabling and disabling extensions.

The Apple menu, home only to desk accessories in System 6, was made more general-purpose: the user could now make often-used folders and applications—or anything else they desired—appear in the menu by placing aliases to them in an "Apple Menu Items" subfolder of the System Folder. System 7 also introduced the following: AppleScript, a scripting language for automating tasks; 32-bit QuickDraw, supporting so-called "true color" imaging, previously available as a system extension; and TrueType, an outline font standard.

The Trash, under System 6 and earlier, would empty itself automatically when shutting down the computer or, if MultiFinder were not running, when launching an application. System 7 reimplemented the Trash as a special hidden folder, allowing files to remain in it across reboots until the user deliberately chose the "Empty Trash" command.

System 7.1 was mainly a bugfix release, with a few minor features added. System 7.1 was not only the first operating system to cost money (all previous versions were free or sold at the cost of the floppies), but also received a "Pro" sibling with extra features. System 7.1.2 was the first version to support PowerPC-based Macs. System 7.1 also introduced the System Enablers as a method to support new models without updating the actual System file. This led to extra files inside the system folder (one per new model supported).

System 7.5 introduced a large number of new features, many of which were based on shareware applications that Apple bought and included into the new system.^{[citation needed]} On the newer PowerPC machines, System 7.5 may have had stability problems partly due to a new memory manager (which can be turned off),^{[citation needed]} and issues with the handling of errors in the PowerPC code (all PowerPC exceptions mapped to Type 11). These issues did not affect 68k-architecture machines.

Mac OS 7.6

Stability improved in PPC Macs with Mac OS 7.6, which dropped the "System" moniker as a more trademarkable name was needed in order to license the OS to the growing market of third-party Macintosh clone manufacturers. Mac OS 7.6 required 32-bit-clean ROMs, and so dropped support for every Mac with a 68000, as well as the Mac II, Mac IIx, Mac IIcx, and Mac SE/30.

Version history

System 7.0 (integrated MultiFinder always enabled)
System 7.0.1 (introduced with LC II and Quadra series)
System 7 Tuner (update for both 7.0 and 7.0.1)
System 7.1
System 7.1 Pro (version 7.1.1, combined with PowerTalk, Speech Manager & Macintalk, Thread Manager)
System 7.1.2 (first version for Macs equipped with a PowerPC processor)
System 7.1.2P (only for Performa/LC/Quadra 630 series, very quickly replaced by 7.5)
System 7.5
System 7.5.1 (System 7.5 Update 1.0 — the first Macintosh operating system to call itself "Mac OS")
System 7.5.2 (first version for Power Macs that use PCI expansion cards, usable only on these Power Macs and PowerBooks 5300 and Duo 2300)
System 7.5.3 (System 7.5 Update 2.0)
System 7.5.3L (only for Mac clones)
System 7.5.3 Revision 2
System 7.5.3 Revision 2.1 (only for Performa 6400/180 and 6400/200)
System 7.5.4, released very briefly and withdrawn within hours. Replaced by 7.5.5
System 7.5.5 Last to support non-32-bit-clean Macs, including all with less than a 68030 CPU except the Macintosh LC.
Mac OS 7.6 (name formally changed because of the experimental clone program, although System 7.5.1 and later used the "Mac OS" name on the splash screen)
Mac OS 7.6.1 Proper PowerPC error handling introduced.

System 7.0.1P
System 7.1P
System 7.1P1
System 7.1P2
System 7.1P3 (last release with new features)
System 7.1P4
System 7.1P5
System 7.1P6

Mac OS 8

Mac OS 8 was released on July 26, 1997, shortly after Steve Jobs returned to the company. It was mainly released to keep the Mac OS moving forward during a difficult time for Apple. Initially planned as Mac OS 7.7, it was renumbered "8" to exploit a legal loophole to accomplish Jobs's goal of terminating third-party manufacturers' licenses to System 7 and shutting down the Macintosh clone market.^[18] 8.0 added a number of features from the abandoned Copland project, while leaving the underlying operating system unchanged. A multi-threaded Finder was included, enabling better multi-tasking. The GUI was changed in appearance to a new shaded greyscale look called Platinum, and the ability to change the appearance themes (also known as skins) was added with a new control panel. This capability was provided by a new "appearance" API layer within the OS, one of the few significant changes.

Apple sold 1.2 million copies of Mac OS 8 in its first two weeks of availability and 3 million within six months. In light of Apple's financial difficulties at the time, there was a large grassroots movement among Mac users to upgrade and 'help save Apple'. Even some pirate groups refused to redistribute the OS.^{[citation needed]}

Mac OS 8.1 saw the introduction of an updated version of the Hierarchical File System called HFS Plus, which fixed many of the limitations of the earlier system (HFS Plus continues to be used in Mac OS X). There were some other interface changes such as separating network features from printing, and some improvements to application switching. However, in underlying technical respects, Mac OS 8 was not very different from System 7.

Mac OS 8.5 focused on speed and stability, with lots of old 68k code replaced by modern code native to the PowerPC. It also improved the appearance on the system, although the theming feature was cut late in development.

Mac OS 8.0 (first version to require a 68040 processor, dropping support for the remainder of the Macintosh II series and other 68030 Macs, added support for the PowerPC G3 processor)
Mac OS 8.1 (last version to run on a 68K processor, added support for USB on the Bondi iMac, added support for HFS+)
Mac OS 8.5 (first version to run only on a PowerPC processor, added built-in support for Firewire on the PowerMac G3)
Mac OS 8.5.1
Mac OS 8.6 (included a new nanokernel for improved performance and Multiprocessing Services 2.0 support, added support for the PowerPC G4 processor)

Mac OS 9

Mac OS 9 was released on October 23, 1999. It was generally a steady evolution from Mac OS 8. Early development releases of Mac OS 9 were numbered 8.7. Mac OS 9 added improved support for AirPort wireless networking. It introduced an early implementation of multi-user support (though not considered a true multi-user operating system by modern standards). An improved Sherlock search engine added several new search plug-ins. Mac OS 9 also provided a much improved memory implementation and management. AppleScript was improved to allow TCP/IP and networking control. Mac OS 9 also made the first use of the centralized Apple Software Update to find and install OS and hardware updates. Other new features included its on-the-fly file encryption software with code signing and Keychain technologies, Remote Networking and File Server packages and much improved list of USB drivers.

Mac OS 9 also added some transitional technologies to help application developers adopt some Mac OS X features before the introduction of the new OS to the public, 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 Mac OS X as well. Other changes were made in Mac OS 9 to allow it to be booted in the "classic environment" within Mac OS X. This is a compatibility layer in Mac OS X (in fact a Mac OS X application, originally codenamed 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 Mac OS 8/9 appearance and do not gain the Mac OS X "Aqua" appearance. Overall, Mac OS is really fucked up.

Mac OS 9.0
Mac OS 9.0.2
Mac OS 9.0.3
Mac OS 9.0.4
Mac OS 9.1
Mac OS 9.2
Mac OS 9.2.1
Mac OS 9.2.2

Mac OS X

Mac OS X (Template:Pron-en)^[19] is the line of graphical operating systems developed, marketed, and sold by Apple Inc. which succeeded the original Mac OS, which had been Apple's primary operating system since 1984. Unlike the earlier Macintosh operating system, Mac OS X is a Unix-based operating system^[20] built on technology developed at NeXT from the second half of the 1980s until early 1997, when Apple purchased the company.^[21]

The first version was Mac OS X Server 1.0 in 1999, which retained the earlier Mac operating system's "platinum" appearance and even resembled OPENSTEP in places. The desktop-oriented version, Mac OS X, followed in March 2001 sporting the new Aqua user interface. Since then, six more distinct "end-user" and "server" versions have been released. In the summer of 2011, Mac OS 10.7 is expected to be released with new features like the Mac App store, Launch Pad, and Mission Control. ^[22]Releases of Mac OS X are named after big cats. For example, Apple calls Mac OS 10.5 "Leopard", while its previous release was called "Tiger".

Versions of Mac OS X:

Mac OS 10 (Cheetah)
Mac OS 10.1 (Puma)
Mac OS 10.2 (Jaguar)
Mac OS 10.3 (Panther)
Mac OS 10.4 (Tiger)
Mac OS 10.5 (Leopard)
Mac OS 10.6 (Snow Leopard)
Mac OS 10.7 (Lion)
Mac OS 10.8
Mac OS 10.9

Timeline

Timeline of Mac operating systems v t e

Notes

^ http://support.apple.com/kb/TA31885?viewlocale=en_US
^ Mike Tuck. "The Real History of the GUI".
^ Bruce Horn. "On Xerox, Apple and Progress".
^ Multi-Mac fate…
^ MultiMac MULTITASKING!
^ Mac II, SE
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s "Macintosh: System Software Version History". Apple Inc. August 7, 2001. Retrieved 2008-04-22.
^ ^a ^b ^c ^d ^e Kottwitz, Randal L. (1987). "The Power User's Manual" (Document). New York: MacUser Publications, Inc. p. 11. {{cite document}}: Unknown parameter |accessdate= ignored (help); Unknown parameter |url= ignored (help)
^ Re: Latest official software versions
^ ^a ^b ^c "Hard Disk 20: Boot From HD20 Locks Up HD20 and Macintosh". Apple Inc. November 10, 1988. Retrieved 2008-05-02.
^ ^a ^b ^c Denny, Bob (November 1985). "Programming for HFS Compatibility". MacTech Magazine. 2 (1). Westlake Village, CA: MacTech: 8. Retrieved 2008-05-02.
^ ^a ^b List of Bugs corrected by System 3.2
^ ^a ^b ^c ^d "System Software: Configs for Mac 128K, XL, 512, & 512KE (7/94)". Apple Inc. August 3, 1994. Retrieved 2008-05-02.
^ http://applemuseum.bott.org/sections/os.html
^ Apple Macintosh before System 7
^ 6.0.5 Press Release
^ http://support.apple.com/kb/TA45090
^ Beale, Steven (October 1997). "Mac OS 8 Ships with No License Deal". Macworld 14 (10): pp. 34–36
^ "What is an operating system (OS)?". 2004-07-15. Retrieved 2006-12-20.
^ http://images.apple.com/macosx/pdf/MacOSX_UNIX_TB_v2.pdf
^ Apple Computer (December 20, 1996). "Apple Computer, Inc. Agrees to Acquire NeXT Software Inc". Retrieved 2007-01-04.
^ http://reviews.cnet.com/8301-13727_7-20020209-263.html

External links

System 7.5.3 from Apple.com
Older Macintosh System Software from Apple.com
Bibliography A list of links to the history of GUIs
Mac OS X history on Mactimeline

[1] ttp://support.apple.com/kb/TA31885?viewlocale=en_US

[2] Mike Tuck. "The Real History of the GUI".

[3] Bruce Horn. "On Xerox, Apple and Progress".

[4] Multi-Mac fate…

[5] MultiMac MULTITASKING!

[6] Mac II, SE

[versionhistory-7] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s "Macintosh: System Software Version History". Apple Inc. August 7, 2001. Retrieved 2008-04-22.

[versiontable-8] Kottwitz, Randal L. (1987). "The Power User's Manual" (Document). New York: MacUser Publications, Inc. p. 11. {{cite document}}: Unknown parameter |accessdate= ignored (help); Unknown parameter |url= ignored (help)

[9] Re: Latest official software versions

[5.0-10] "Hard Disk 20: Boot From HD20 Locks Up HD20 and Macintosh". Apple Inc. November 10, 1988. Retrieved 2008-05-02.

[5.0HFS-11] Denny, Bob (November 1985). "Programming for HFS Compatibility". MacTech Magazine. 2 (1). Westlake Village, CA: MacTech: 8. Retrieved 2008-05-02.

[3.2-12] List of Bugs corrected by System 3.2

[3.4-13] "System Software: Configs for Mac 128K, XL, 512, & 512KE (7/94)". Apple Inc. August 3, 1994. Retrieved 2008-05-02.

[14] ttp://applemuseum.bott.org/sections/os.html

[15] Apple Macintosh before System 7

[16] 6.0.5 Press Release

[17] ttp://support.apple.com/kb/TA45090

[18] Beale, Steven (October 1997). "Mac OS 8 Ships with No License Deal". Macworld 14 (10): pp. 34–36

[ten_not_x-19] "What is an operating system (OS)?". 2004-07-15. Retrieved 2006-12-20.

[20] ttp://images.apple.com/macosx/pdf/MacOSX_UNIX_TB_v2.pdf

[apple-acquisition-21] Apple Computer (December 20, 1996). "Apple Computer, Inc. Agrees to Acquire NeXT Software Inc". Retrieved 2007-01-04.

[22] ttp://reviews.cnet.com/8301-13727_7-20020209-263.html

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@@ Line 314: / Line 314: @@
 Mac OS 9 was released on October 23, 1999. It was generally a steady evolution from Mac OS 8. Early development releases of Mac OS 9 were numbered 8.7. Mac OS 9 added improved support for AirPort wireless networking. It introduced an early implementation of multi-user support (though not considered a true multi-user operating system by modern standards). An improved [[Sherlock (software)|Sherlock]] search engine added several new search plug-ins. Mac OS 9 also provided a much improved memory implementation and management. AppleScript was improved to allow TCP/IP and networking control. Mac OS 9 also made the first use of the centralized Apple Software Update to find and install OS and hardware updates. Other new features included its on-the-fly file encryption software with code signing and Keychain technologies, Remote Networking and File Server packages and much improved list of USB drivers.
-Mac OS 9 also added some transitional technologies to help application developers adopt some Mac OS X features before the introduction of the new OS to the public, again easing the transition. These included new APIs for the [[file system]], and the bundling of the [[Carbon (API)|Carbon]] library that apps could link against instead of the traditional API libraries &mdash; apps that were adapted to do this can be run natively on Mac OS X as well. Other changes were made in Mac OS 9 to allow it to be booted in the "classic environment" within Mac OS X. This is a compatibility layer in Mac OS X (in fact a Mac OS X application, originally codenamed 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 Mac OS 8/9 appearance and do not gain the Mac OS X "Aqua" appearance.
+Mac OS 9 also added some transitional technologies to help application developers adopt some Mac OS X features before the introduction of the new OS to the public, again easing the transition. These included new APIs for the [[file system]], and the bundling of the [[Carbon (API)|Carbon]] library that apps could link against instead of the traditional API libraries &mdash; apps that were adapted to do this can be run natively on Mac OS X as well. Other changes were made in Mac OS 9 to allow it to be booted in the "classic environment" within Mac OS X. This is a compatibility layer in Mac OS X (in fact a Mac OS X application, originally codenamed 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 Mac OS 8/9 appearance and do not gain the Mac OS X "Aqua" appearance. Overall, Mac OS is really fucked up.
 *[[Mac OS 9|Mac OS 9.0]]
 *Mac OS 9.0.2