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 and included improved TCP/IP functionality with Open Transport 2.5. Other features new to Mac OS 9 include:
versions of OS X prior to 10.5 include a compatibility layer 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 OS X 10.4; however, x86 versions of OS X do not support the Classic environment. As a workaround for Intel-based Macs, Mac OS 9 can be emulated up to version 9.0.4 by using SheepShaver, a PowerPC emulator. It cannot emulate versions newer than 9.0.4 because SheepShaver does not emulate a memory management unit. The PearPC PowerPC emulator does not support Mac OS 9. Recently QEMU added support for emulating Mac OS 9 and PowerPC versions of OS X however.
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 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.
