Robert W Taylor, who was instrumental in creating the internet and the modern personal computer, has died in California.
His son, Kurt, said Mr Taylor was 85 when he died on Thursday in Woodside.
Mr Taylor funded researchers or led teams of scientists who are responsible for some of the most important technologies of the modern world.
They include the computer mouse and computers that use graphics such as icons and windows - the kind of command system that is universal on modern devices.
In 1966, when Mr Taylor worked for the Pentagon, he oversaw the creation of a single computer communications network called Arpanet, which linked researchers around the country and later evolved into the internet.
Mr Taylor later shepherded a team at the Xerox Palo Alto Research Centre that developed the Alto personal computer.
Additional reporting by AP