Calc is an interactive calculator which provides for easy large numeric caluclations, but which also can be easily programmed for difficult or long calculations. It can accept a command line argument, in which case it executes that single command and exits. Otherwise it enters interactive mode. In this mode, it accepts commands one at a time, processes them, and displays the answers. In the simplest case, commands are simply expressions which are evaluated. For example, he following line can be input: > 3 * (4 + 1) and the calculator will print 15. Commands are statements in a C-like language, where each input line is treated as the body of a procedure. Thus he copmmand line can contain variable declarations, expressions, labels, conditional tests, and loops. Assignments to any variable name will automatically define that name as a global variable. For more information on the program, run 'calc help help'.