American computer scientist who, with Daniel Bricklin, developed the first spreadsheet program for personal computers. This program, called "Visicalc," allowed accountants, scientists, and engineers to perform a huge number of interdependent calculations automatically, and to automatically recalculate the results if any input parameters were changed. This development quickly led to industry standard programs such as Lotus 1-2-3 and Excel, which have since improved significantly, becoming exceptionally powerful tools for business management, finance, engineering design, and science.