Software used varies from industry to industry and from application to application. MathCAD is common across a number of industries for what are often referred to as "hand calculations". ANSIS is also common for static FEA (Finite Element Analysis) and Abacus is common for nonlinear and dynamic FEA. The nuclear industry and aerospace both use MathCAD to a great extent. The nuclear industry usually uses ANSIS for static FEA and the aerospace industry uses MSC Nastran/Patran.