Calcoo is a scientific calculator designed to provide maximum usability. The features that make Calcoo better than (at least some) other calculator programs are:

- bitmapped button labels and display digits to improve readability
- no double-function buttons - you need to click only one button
for any operation (except for arc-hyp trigonometric functions)
- undo/redo buttons
- both RPN (reverse Polish notation) and algebraic modes
- copy/paste interaction with X clipboard
- display tick marks to separate thousands
- two memory registers with displays
- displays for Y, Z, and T registers