This article discusses the life and work of Douglas Engelbart, who played a major role in modern computing – he invented the mouse, hyperlinks, and text and graphics editing, among other things. He demonstrated all of these inventions in a presentation in 1968 that would come to be nicknamed The Mother of All Demos.
One fascinating invention of his didn't survive the test of time: The keyset was a device that could be used for entering text while simultaneously using a mouse. The keyset had five keys and was programmed to output a character when a certain combination of keys were pressed at the same time. With five keys you could program 31 different combinations, so the keyset could work with the entire alphabet and some special characters.