Calculax is a simple C program acting as a interpreter
Calculax has been made in C, and uses the ncurses library.
$ ./configure
$ make
$ make install
> 42 + 42
> 84
> life = 42
> success!
> life + 12
> 43
Use TAB key for auto-completion of variable names
> li+[TAB]
becomes
> life
Use the keyboard arrow UP and DOWN to navigate through history