Well Tim Paterson for starters. He wrote their wildest hacks. Like this program that translated old CP/M binaries into i8086 code dynamically at runtime during the loading process, so that DOS could seamlessly transition people away from the Digital Equipment Corporation platform. Plus he wrote commands like `DEBUG` which like GDB normally require special kind of giftedness in order to create. What would Microsoft have been, if it weren't for unsung heroes like him?