1. <computer> The Colossus and Colossus Mark II computers used by Alan Turing at Bletchley Park, UK during the Second World War to crack the "Tunny" cipher produced by the Lorenz SZ 40 and SZ 42 machines. Colossus was a semi-fixed-program vacuum tube calculator (unlike its near-contemporary, the freely programmable Z3).
2. The computer in the 1970 film, "Colossus: The Forbin Project". Forbin is the designer of a computer that will run all of America's nuclear defences. Shortly after being turned on, it detects the existence of Goliath, the Soviet counterpart, previously unknown to US Planners. Both computers insist that they be linked, whereupon the two become a new super computer and threaten the world with the immediate launch of nuclear weapons if they are detached. Colossus begins to give its plans for the management of the world under its guidance. Forbin and the other scientists form a technological resistance to Colossus which must operate underground.