shell program surrounding the Disk Operating System (DOS) of a personal computer. It turns the display into a desk-top that is basically a menu from which one selects and runs PC applications. A shell program is a software package with an integration capability. This is created when the resident operating system and application programs are surrounded with a superimposed "shell" of command structures and menus. Microsoft Windows,Linux, and IBM's OS/2, different examples of operating environments, do away with the DOS prompt. An alternative operating environment allows switching of programs, windowing, and cut-and-paste capabilities. Windowing is the capability to accommodate more than one program if the accountant wants the main memory partitioned to handle the programs. For each program in memory, a separate window is displayed on the screen.