It’s called a mouse because the wire that extends from the rear of the gadget’s body resembles a mouse’s tail. Douglas Englebart received a patent for his early version of the tool — an "X-Y Position Indicator for a Display System" — forty years ago today, on November 17, 1970. The device that he and colleague Bill English built used two perpendicular gear-wheels, each of which moved along a separate axis. This was not the first mouse invented. Several weeks before Englebart received his patent, Telefunken began to market its roller-based mouse. English went on to develop the mouse ball that is the basis for the kind of mice still in use today.

Quote: "The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." — Ted Nelson