C-style arbitrary precision calculator (debug info)
Calc is an interactive calculator which provides for easy large numeric calculations, 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.