4allCalc Calculator

4allCalc is an all purpose calculator with scientific functions, easy transfer to/from the clipboard (Variable "Z"), variables, regression, numeric forms for programmers (binary, octal, hexadecimal), overflow simulation, detailed error messages, online help.
4allCalc does not try to simulate a real calculator; There's an entry field and a result field; you don't have an = button.

4allCalc recalculates the result after every keystroke. You enter a formula like you would in a programming language.