Mac OS 9

Mac OS 9 is the ninth major release of Apple's classic Mac OS operating system which was succeeded by OS X. Introduced on October 23, 1999, it was promoted by Apple as "The Best Internet Operating System Ever", highlighting Sherlock 2's Internet search capabilities, integration with Apple's free online services known as iTools and improved Open Transport networking. While Mac OS 9 lacks protected memory and full pre-emptive multitasking, lasting improvements include the introduction of an automated Software Update engine and support for multiple users.
Apple discontinued development of Mac OS 9 in late 2001, transitioning all future development to Mac OS X. The final updates to Mac OS 9 addressed compatibility issues with Mac OS X while running in the Classic Environment and compatibility with Carbon applications. At the 2002 Worldwide Developers Conference, Steve Jobs began his keynote address by staging a mock funeral for OS 9.
Features.
Apple billed Mac OS 9 as including "50 new features" and heavily marketed its Sherlock 2 software, which introduced a "channels" feature for searching different online resources and introduced a QuickTime-like metallic appearance. Mac OS 9 also featured integrated support for Apple’s suite of Internet services known as iTools (later re-branded as .Mac, then MobileMe, which was replaced by iCloud) and included improved TCP/IP functionality with Open Transport 2.5.
Other features new to Mac OS 9 include:
Mac OS 9 and the Classic Environment.
PowerPC versions of Mac OS X prior to 10.5 include a compatibility layer (a shell) called Classic, enabling users to run applications and hardware requiring Mac OS 9 from within OS X. This is achieved through running Mac OS 9 without access to its Finder inside OS X. This requires Mac OS 9 to be installed on the computer even though computers that can run the Classic environment are not necessarily able to boot into Mac OS 9. Some Mac OS 9 applications do not run well in Classic. They demonstrate screen redraw problems and lagging performance. In addition, some drivers and other software which directly interact with the hardware fail to work properly.
In May 2002, at Apple's Worldwide Developers Conference in San Jose, California, Steve Jobs, accompanied by a coffin, held a mock funeral to announce that Apple had stopped development of Mac OS 9. Mac OS 9.2.2, released in December 2001, was the final version of Mac OS 9 and the "classic" Mac OS.
In June 2005, Jobs announced that the Macintosh platform would be transitioning to Intel x86 microprocessors. Developer documentation of the Rosetta PowerPC emulation layer revealed that applications written for Mac OS 8 or 9 would not run on x86-based Macs. The Classic Environment remains in the PowerPC version of 10.4; however, x86 versions of OS X do not support the Classic environment.
Mac OS 9 can be emulated by using SheepShaver, a PowerPC emulator available on multiple operating systems, including Intel-based Macs. However, SheepShaver cannot run Mac OS versions newer than 9.0.4, as there is no support for a memory management unit. The PearPC PowerPC emulator does not support Mac OS 9. QEMU has experimental support for running Mac OS 9 using PowerPC G4 emulation.
Availability.
While Mac OS 9 is no longer supported by Apple, retail copies are still available from several Internet businesses at varying prices.
Although now classed as abandonware, as development on it has ended, it is still in use by those who cannot upgrade to OS X due to hardware limitations or prefer it to OS X. Mac OS 9 is also a popular choice for retrocomputing hobbyists. Mac gamers also sometimes revert to Classic (often via emulation) or native OS 9 in order to play games that are not supported on OS X; for example: "Bugdom", "Nanosaur", "Oregon Trail", "Civilization II", and the "Marathon Trilogy".
Other uses.
Aside from Apple-branded hardware that is still maintained and operated, Mac OS 9 can be operated in other environments such as Windows and Unix. For example, the aforementioned SheepShaver software was not designed for use on x86 platforms and required an actual PowerPC processor present in the machine it was running on similar to a hypervisor. Although it provides PowerPC processor support, it can only run up to Mac OS 9.0.4 because it does not emulate a memory management unit.
Version history.
Updates to Mac OS 9 include 9.0.4, 9.1, 9.2.1, and 9.2.2. Mac OS 9.0.4 was a collection of bug fixes primarily relating to USB and FireWire support. Mac OS 9.1 included integrated CD burning support in the Macintosh Finder and added a new Window menu in the Finder for switching between open windows. Mac OS 9.2 increased performance noticeably and improved Classic Environment support.