hsiloP 1.0

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.
Main features:
- 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.