The Computer History Museum, where Engelbart had been a fellow since 2005, says he died early Wednesday. The museum in Mountain View, Calif., was notified of the death in an email from his daughter, Christina. The cause of death wasn't immediately known.
Engelbart's biggest breakthrough was the computer mouse, which he developed in the 1960s and patented in 1970. At the time, it was a wooden shell covering two metal wheels.
The notion of operating the inside of a computer with a tool on the outside was ahead of its time. The mouse wasn't commercially available until 1984, with Apple's new Macintosh.