IBM, Xerox's GUI, Jobs, Gates, go watch "Pirates of Silicon Valley"...
The GUI timeline
http://accad.osu.edu/~waynec/history/lesson16b.html
You can thank Alan Kay for those lil icons on your desktop.
GUI goes FURTHER back than that, but, Alan Kay did it on the PC.
http://www.sensomatic.com/chz/gui/history.html
Here's an interesting sound-bite from Jobs on Microsoft.
http://www.youtube.com/watch?v=upzKj-1HaKw
He's right though...
Gates basically had a deal with IBM, but IBM thought business machines only (hence "BM") in their name.
Gates envisioned PCs in homes, IBM thought DOS was going nowhere, so Gates took it and ran with it ---> MS-DOS.
Along with Xerox's GUI, tada.
"640 K ought to be enough for anybody."
-- Bill Gates, 1981
Ya right Bill, we're doing Dual-Cores now baby...