One of the first architectural decisions that Bud and I made for the Macintosh system software in the spring of 1981 was that we were only going to try to run one application at a time. We barely had enough RAM or screen space to do even that, and we thought that we'd benefit from the resultant simplifications. Besides, multi-tasking was supposed to be Lisa's forte, and we didn't want to usurp all of the reasons for buying a Lisa.
