This is Henri Gavin's 2D/3D frame analysis program, for analysing the stresses, deflections and natural frequencies of 2D and 3D frames and trusses, with elastic and geometric stiffness.

Computes the static deflections, reactions, internal element forces, natural frequencies, mode shapes and modal participation factors of two- and three- dimensional elastic structures using direct stiffness and mass assembly. Graphical output and mode shape animation via Gnuplot version 4.0.