Doug Engelbart, inventor of computer mouse

SAN FRANCISCO - Doug Engelbart, 88, the inventor of the computer mouse and developer of early incarnations of e-mail, word processing programs and the Internet, died late Tuesday.

The Computer History Museum, where Engelbart had been a fellow since 2005, announced the death. The cause was not immediately known.

Engelbart said his work was about "augmenting human intellect," but it boiled down to making computers user-friendly. One of the biggest advances was the mouse, which he developed in the 1960s and patented in 1970. At the time, it was a wooden shell covering two metal wheels.

The mouse was not commercially available until 1984, with Apple's Macintosh. But the patent had a 17-year life span, and in 1987 the technology fell into the public domain - meaning Engelbart could not collect royalties as the mouse went into wide use. At least one billion have been sold since the mid-1980s.

Among Engelbart's other key developments in computing, along with his colleagues at Stanford Research Institute (SRI) and his own lab, the Augmentation Research Center, was the use of multiple windows. Engelbart's lab also helped develop ARPANet, the government research network that led to the Internet.

In 1997, Englebart won the most lucrative award for American inventors, the $500,000 Lemelson-MIT Prize. Three years later, President Bill Clinton bestowed Engelbart with the National Medal of Technology.

Douglas Carl Engelbart was born Jan. 30, 1925, and grew up on a small farm near Portland, Ore. He studied electrical engineering at Oregon State University, taking two years off during World War II to serve as a Navy electronics and radar technician. After the war, Engelbart worked as an electrical engineer for NASA's predecessor, NACA, at its Ames Laboratory. Engelbart left Ames to pursue his doctorate at University of California, Berkeley.

He earned his degree in 1955 and joined the faculty, only to leave for the research position at Stanford Research Institute, now SRI International.

In 1990, Engelbart started the Bootstrap Institute, which researches ways to advance collaboration on complex problems.