A free program for Windows, by thomas-okken.

Free42 is a free, open-source scientific calculator for your desktop devices. It is based on the HP-42S, one of the most popular scientific calculators of all time. The calculator can be used for a wide range of purposes, from simple calculations to advanced calculations, such as solving complex equations and performing special functions.

In addition, Free42 supports many programming languages, making it easy to write programs for a wide range of purposes.

Free42 can be used to perform many calculations, including simple and advanced arithmetic, complex numbers, probability, and statistics. It can also be used for simple data analysis, such as calculating the average of a set of numbers. It can even be used to calculate the area under a curve.