System 7
In 1991, Apple introduced System 7, an upgrade that greatly modernized the Mac. It incorporated many features that would guide future development: seamless multitasking (albeit cooperative), color icons, personal file sharing, virtual memory, and a hierarchical System folder to help organize Control Panels and Extensions. The Mac interface also evolved for System 7, growing a bit more sophisticated as shown in Figure 1-2.

Figure 1-2. The System 7 desktop
System 7 also laid the foundation for three very important technologies:
- QuickTime
A powerful multimedia technology for manipulating, enhancing, storing, and streaming video, graphics, sound, and animation.
- ColorSync
A set of system routines for color management allowing for graphics to be color managed from editing to print.
- AppleScript
An easy-to-use scripting language that allows you to automate tasks on your system.
Although System 7 was years ahead of every other operating system from the ease-of-use perspective, not all was rosy with this release. With all the new functionality, the Toolbox had become even more fragile than its predecessors. It turned out that cooperative multitasking, where applications are expected to play nice with each other, meant that any application could hog all the processor time and, in effect, lock up a system. And, most glaringly, the Mac OS did not provide memory protection between programs. ...