Shellcalc (sc) is a lightweight and versatile reverse polish notation (RPN) calculator for the command-line. It implements access to the basic operations and many functions from the glibc math library.
REPCAL (REverse Polish CALculator) is a light and fast calculator in RPN (reverse polish notation) mode for the console (command line). It is written in 180 lines of Python code, and can be used both interactively or inside shell scripts.