Mac OS 9 is the last version of what has since become known as the classic Mac OS, introduced by Apple Computer on October 23, 1999.

The Finder in Mac OS 9.

Introduced October 1999, Mac OS 9 was advertised by Apple as having "50 new features. Codenamed Sonata, and originally intended to debut as Mac OS 8.7, Mac OS 9 is, by some, considered the most functional and stable version of the original Mac OS, though OS 9 still does not have some features common to modern operating systems, such as protected memory (which, reportedly was implemented in beta versions of Mac OS 9.1, but pulled at Steve Jobs' command), and pre-emptive multitasking. However, it did ship from Apple with many improvements over earlier versions, such as improved Open Transport networking, and an upgraded search tool (Sherlock 2), though it did retain the platinum theme introduced in Mac OS 8. Unlike previous versions, it supports multiple users without third-party additions. Perhaps most importantly, Mac OS 9 dropped support for the Motorola 680x0 series of processors, becoming the first PowerPC-only Macintosh operating system. Parties interested in such things have noted that despite that fact, there are still many strings in the System suitcase which make references to obsolete 68K machinery.

Apple billed OS 9 as "best Internet operating system ever". It was the first Mac OS to include an internet-based Software Update system, and Apple offered the iTools (now .Mac) suite of tools for free to users of OS 9.

Apple updated OS 9 with a series of bugfixes and minor enhancements, most notably versions 9.0.4 and 9.1 (which provided CD burning support within the Finder), in 2000 and 2001. Another update, Mac OS 9.2.1 was introduced in 2001, but only to improve the functioning of the Classic environment in the new Mac OS X (and was followed by 9.2.2 with the same purpose). However, OS 9.2.x is a fully functional operating system and can be used as the startup OS on Macs that do not have an OS X-only boot.

In May of 2002, at Apple's Worldwide Developers Conference in San Jose, California, Apple CEO Steve Jobs delivered a mock "funeral" for Mac OS 9 during his keynote address, dressed in black and toting a coffin. The purpose of the theatrics was to announce that Apple had stopped all development of OS 9. Mac OS 9.2.2, introduced in 2002, was the final version of Mac OS 9, and indeed, of the classic Mac OS.

Mac OS X provides a compatibility layer called Classic that runs a complete Mac OS 9 installation within OS X, for applications and hardware that expect to be running under OS 9.

References

• [Multiple Users in OS 9] (University of Chicago, Physical Sciences Division)

External links

• Technote TN1176 Mac OS 9 from apple.com