The operating system running on ES is developed for NEC's SX Series supercomputers. (The SX series are vector supercomputers designed, manufactured, and marketed by NEC). SUPER-UX is an operating system that takes the function from BSD and SVR4.2MP as an operating system based on UNIX System V, and strengthens the function necessary for the super computer in addition. (SUPER-UX, Berkeley Software Distribution (BSD) and SVR4.2MP are Unix based operating systems).