4DOS is a command line interpreter by JP Software, designed to replace the default command interpreter COMMAND.COM in DOS and Windows 95/98/Me. Related products that substitute for Windows NT's command interpreter (4NT) and IBM's OS/2 command interpreter (4OS2) are also available. The Take Command product was designed as a compatible interpreter but requiring and enjoying a GUI environment (Windows or PM). 4DOS was written by Rex Conn and Tom Rawson; it was first released in 1989.