StSoft Calculator

From StSoft:

Convenient and powerful calculator program. It supports the common arithmetic operations (+, -, *, /, ^) and more then 30 internal functions (trigonometric, logarithmic, hyperbolic etc.). The main feature of the calculator is possibility of creating users functions and variables. Expressions must be input in natural mathematic note (for example (8+2)^3+Sin(30)/2 or 3.12*Log(2*4+8)-2 ). Understandable and convenient interface, flexible tuning, possibility of saving intermediate results in file, detailed instruction, easily to return to the previous expressions and many other advantages.