MEX

MEX (multiple exposure) is a windowing system used on 68k-based GL2-2.x and GL2-3.x through 4D1-2.x MEX was introduced in GL2-2.x as a locally run GUI system. All programs were loaded by typing the command in the terminal prompt, it lacked title bars and had limited color palettes and resolution. It's speculated some compatiblity was retained in the early 4D1 System V releases, but very little of this has survived.