Smaller and a little more powerful than the flagship Testarossa, the 288 GTO was the fastest Ferrari is its day. It should have been, it was designed as a racer. GTO? Gran Turismo Omologato or, in somewhat less evocative terms, Homologated GT. Homologation is the process of certifying that a number of identical units have been made; road cars are homologated by transport, road based race cars are homologated for competition by the FIA, the ruling body of motor sport, once a specified number have been built.
Over 1959-61, Ferrari had been building the short wheelbase 250 GT for road and competition use; when the FIA announced a GT championship for 1962, Ferrari needed something lower and lighter. The rules of the day stated that 100 identical cars should be built in 12 consecutive months, but that special bodied versions could be made once the 100 had been completed; the 250 GT had already been accepted a GT car, so the new car was submitted for approval with the revised bodywork.