I am occasionally in the position of having to calculate things. I have several different tools available: bc, Calculator, or Excel. It's a very nice feature to be able to cut and paste numbers from my work into my calculator, but I'm still considering bringing in my physical calculator from home. If at all possible, I would like to avoid that.

Basically, bc doesn't have all the functions I need. Calculator (or xcalc) is largely fine, except when I want to calculate a complicated formula, and then I get lost in parentheses. Excel is fine, but it's a damn spreadsheet. Also, it's hard to do hexadecimal in Excel. Or binary.

Matlab would work, but I don't have a license. Or I could use any program that simulated the workings of a decent HP or TI calculator. Does anybody use a calculator program that can be downloaded for the asking?