The FEBio software suite is a set of software tools for nonlinear finite element analysis in biomechanics and biophysics. The software was originally developed by personnel in the Musculoskeletal Research Laboratories at the University of Utah. Currently, development, distribution and support are handled as a joint effort between the University of Utah and the Musculoskeletal Biomechanics Laboratory at Columbia University. FEBio is specifically focused on solving nonlinear large deformation problems in biosolid mechanics, and the software suite is composed of the following three packages: