Philip Don Estridge, known as Don Estridge, led the development of the IBM Personal Computer (PC), arguably the most important computer in the history of computers. It's the creation of this computer that's led to the types of computer that we have today.
The IBM PC was designed as a way for the company to get into the small computer market, dominated at the time by Commodore, Atari and Apple. The revolutionary part about the computer was that it was designed by using off-the-shelf parts available from OEMs, rather than creating brand-new technology. This let IBM create the PC in less than a year and keep prices down to affordable levels.
Even more surprising for the time was that IBM decided to use an open architecture, so that other manufacturers could produce and sell peripherals without having to purchase a license. As we all know, this open architecture also meant that other companies could start creating their own IBM-compatible computers. It's this architecture that exists today and even Apple has changed to embrace it when it switched to using Intel processors in its Mac computers.
The IBM PC also opened up the door for Intel's and Microsoft's success. Without Don Estridge and IBM the world would be a very different place.