A Reverse Polish Notation calculator

hsiloP is a Reverse Polish Notation calculator supporting everything from trigonometric functions to combinatorics.

The interface is minimalist: the program starts out as a small green rectangle floating above your other windows.

Enter numbers, and the hsiloP rectangle grows to display all the numbers in a "stack" (the picture to the left shows hsiloP running, with my desktop behind it).

Each command that users may enter (such as or atan or factor) removes numbers from the bottom of the stack and replace them with a result.

Here are some key features of "hsiloP":

￭ Trigonometric functions, including an atan2 function that takes an (x, y) pair and returns an angle in the full range from -180 to 180 degrees (an ordinary atan cannot distinguish an angle from the opposite angle)
￭ Display of numbers in different bases: decimal, hexadecimal, binary, or octal.
￭ Bitwise arithmetic operators (AND, OR, XOR, and NOT)
￭ Full history of the commands you have typed in during a session, and the ability to scroll back through the history or to copy it.
￭ Combinatorial functions, factoring, GCF and LCM, and much more.