Mac OS 9 is the final major release of Apple's "Classic" Mac OS. Introduced on October 23 1999, Apple positioned it 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 the functionality of a modern operating system, such as 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 2002, transitioning all future development to Mac OS X. Since that time, no updates have been released. The final updates to Mac OS 9 addressed compatibility issues with OS X while running in the Classic Environment and compatibility with Carbon applications.
