Calc98 is a Scientific engineering statistical and financial pocket calculator simulator program for the Microsoft Windows operating systems. It includes a comprehensive set of conversions, constants and physical property data, a built-in periodic table of the elements, number base conversions, vectors, matrices and complex numbers. It is user customisable and supports algebraic and RPN logic. Other features include a stopwatch, Roman numerals, and copy/paste with other applications. This version can be installed on Windows Mobile 5.0 devices (see FAQ at calculator.org) but we recommend the newer version 5.6 for Windows Mobile 5.0 and Windows Mobile 2003 Second Edition devices, with full support for landscape mode.