A Billion Mice Later, Inventor of the Computer Mouse Dies at 88
This was a man who was at the forefront of computing and of several technologies we take for granted today. In one way or another, he worked on early versions of email, word processing, and video teleconferences at a California research institute, BBC News reports.

Born in Portland, Oregon on January 30, 1925, Engelbart would end up going to Oregon State College at Corvallis, completing half of his studies before being drafted into the United States Navy where he served as a radar technician. When he returned, he went back to college and earned his Bachelor's degree in electrical engineering. Later on, he would earn a Master of Science degree and a Ph.D, both at the University of California, Berkeley.
It was in 1967 that he applied for a patent for the computer mouse. A year later, he would showcase several technologies at the Mother of All Demos (embedded above). In 1970, Engelbart received his mouse patent, though he never made much money from it since the patent expired in 1987 before it was a widely used peripheral. Since then, it's estimated that more than one billion computer mice have been sold.
Engelbart is survived by his wife, Karen O' Leary Engelbart; daughters Gerda, Diana, and Christina; his son Norman; and nine grandchildren.