The man behind the computer mouse, who transformed the way people work, play and communicate, has died at 88.
Technology visionary Doug Engelbart died from acute kidney failure at his California home after a long battle with Alzheimer's disease, one of his daughters, Diana Engelbart Mangan, said.
Mild-mannered Engelbart, whose first computer mouse was a wooden shell with metal wheels, had audacious ideas. Long before Apple founder Steve Jobs became famous for his dramatic presentations, Mr Engelbart dazzled the industry at a San Francisco computer conference in 1968.
Working from his house with a home-made modem, he used his lab's elaborate new online system to illustrate his ideas to the audience, while his staff linked in from the lab. It was the first public demonstration of the mouse and video teleconferencing, prompting a standing ovation.
"We will miss his genius, warmth and charm," said Curtis Carlson, chief executive of SRI International, where Mr Engelbart used to work. "Doug's legacy is immense. Anyone in the world who uses a mouse or enjoys the productive benefits of a personal computer is indebted to him."
In the 1950s and 60s, when mainframe computers took up entire rooms and were fed data on punch cards, Mr Engelbart was already envisaging a day when computers were far more intuitive to use. One of the biggest advances was the mouse, which he developed in the 1960s and patented in 1970. The idea was way ahead of its time. The mouse did not become commercially available until 1984, with the release of Apple's then-revolutionary Macintosh computer.
Mr Engelbart's conceived the mouse so early in the evolution of computers that he and his colleagues did not profit much from it. The technology passed into the public domain in 1987, preventing him from collecting royalties on the mouse when it was in its widest use. At least one billion have been sold since the mid-1980s. Now their usage is waning as people merely swipe their finger across a display screen.
"There are only a handful of people who were as influential," said Marc Weber, founder and curator of the internet history programme at the Computer History Museum, where Mr Engelbart had been a fellow since 2005. "He had a complete vision of what computers could become at a very early stage."
Among Mr Engelbart's other key developments in computing, along with his colleagues at SRI International and his own lab, the Augmentation Research Centre, was the use of multiple windows. His lab also helped develop ARPANet, the government research network that led to the internet.
He played down the importance of his inventions, stressing instead his vision of using collaboration over computers to solve the world's problems. "Many of those firsts came right out of the staff's innovations - even had to be explained to me before I could understand them," he said in a biography written by his daughter. Mr Engelbart is survived by his wife, Karen O'Leary Engelbart; his four children, Diana, Christina, Norman and Greda; and nine grandchildren.