The LESM (Linear Elements Structure Model) software, designed by Prof. Luiz Fernando Martha of the Department of Civil and Environmental Engineering of PUC‐Rio and entirely developed at Tecgraf/PUC-Rio Institute, was created as an educational tool for teaching Structural Analysis courses. The software performs static linear-elastic analysis of two-dimensional and three-dimensional reticulated structures (structural models formed by bars), such as trusses, frames and grillage. The free, open source and fully documented software was written in MATLAB programming language (script language) using the Object-Oriented Programing Paradigm (OOP), which allows users to implement new procedures with relative ease.