The slide rule was used for over 400 years as a calculating/estimation tool. Abandoned with the advent of hand-held calculators, computers and smart phones, their elegant simplicity is still a thing of wonderment. This program replicates the most common types of slide rules: Straight, circular, spiral and cylindrical. Dozens of scales are included and numerous features that could never exist on a physical slide rule are also included, such as color options, numeric displays of the values under the hairlines, and so on.

Slide rules were used to go to the moon and to build bridges, skyscrapers, tunnels, aqueducts and nearly everything else. Slide rules were simple to use and accurate enough for most occasions.