What’s makes my calculator different is that it’s geared towards function vs. pushing buttons and duplicating the look of a calculator. Frankly, I can type faster than I can hit buttons on with the mouse. Also, by not having a button pad, it takes up less screen real estate. It has stack of previously entered values that can be recalled by pressing the up arrow. And if you’re so inclined, you can program it. There are several built-in functions including trig functions and It’s definitely a function over form approach.
If there was one annoyance I had with it, it was that it displayed decimal numbers to more than two digits of precision. Two digits of precision suffices for most chores and so I added a checkbox with a dollar sign that toggles between full precision and two digits.
I’ve also right-aligned the text which seems to be what most other calculators do. You can get it from the downloads page. Vista only.