Editing Mac OS 9 (section)

==Mac OS 9 and the Classic Environment==
{{main|Classic Environment}}
[[PowerPC]] versions of [[macOS|Mac OS X]] prior to [[Mac OS X Leopard|10.5 Leopard]] include a compatibility layer called [[Classic Environment|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 machine, even though most Macs that can run the Classic environment are not necessarily able to boot into Mac OS 9 natively. 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]]<ref name="Apple WWDC 2002-The Death Of Mac OS 9" /> to announce that Apple had stopped the development of Mac OS 9. The final version of Mac OS 9 and the "classic" Mac OS was Mac OS 9.2.2, released in December 2001.

In June 2005, Jobs announced that the Macintosh platform would be transitioning to [[Intel x86]] microprocessors. Developer documentation of the [[Rosetta (software)|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 [[Mac OS X Tiger|10.4 Tiger]]; however, x86 versions of OS X and the PowerPC version of [[Mac OS X Leopard|10.5 Leopard]] do not support the Classic environment.

Mac OS 9 can be emulated by using [[SheepShaver]], a PowerPC emulator available on multiple operating systems. It can be run on any machine with a supported CPU platform, including [[Intel-based Mac]]s. Initially, it required an actual PowerPC processor present in the machine it was running on similar to a [[hypervisor]], but support for x86 platforms was added at a later date. SheepShaver cannot run Mac OS versions newer than 9.0.4, however, as it does not have support for a [[memory management unit]]. The [[PearPC]] PowerPC emulator does not support Mac OS 9.<ref>{{Cite web |title=Frequently Asked Questions |url=http://pearpc.sourceforge.net/faq.html |url-status=live |archive-url=https://web.archive.org/web/20061115202931/http://pearpc.sourceforge.net/faq.html |archive-date=2006-11-15 |access-date=2006-11-16 |publisher=PearPC Developers}}</ref> [[QEMU]] has experimental support for running Mac OS 9 using PowerPC G4 emulation.<ref>{{Cite web |date=2018-11-07 |title=Emulate Mac OS 9 With QEMU |url=https://www.jamesbadger.ca/2018/11/07/emulate-mac-os-9-with-qemu/ |access-date=2021-03-08 |website=James Badger |language=en |archive-date=2020-11-08 |archive-url=https://web.archive.org/web/20201108130604/https://www.jamesbadger.ca/2018/11/07/emulate-mac-os-9-with-qemu/ |url-status=live }}</ref>