PG Calculator is a powerful scientific skinnable calculator. It works in algebraic and RPN mode, recognizes real and complex numbers, and allows simple vectors manipulations. It has up to 80 built-in functions, allows user-defined variables, supports numbers inputing in binary, octal, hexadecimal, and exponential formats. Graphical user interface can be easy changed with skins. WWW: http://www.pgcalc.net/