InVesalius is an Open Source organization that works developing free software for reconstruction of computed tomography and magnetic resonance images. The software is mainly used for rapid prototyping, teaching, forensics, and in the medical field. It is possible to use it on the Microsoft Windows, GNU/Linux and Apple Mac OS X platforms. InVesalius main software started began their development on 2001 by Centro de Tecnologia da Informação Renato Archer (CTI), in Brazil, later it was released under GNU license and more practitioners joins the organization to improve their development. At that time, there was no medical image software in Portuguese that fulfilled the Brazilian hospitals and clinics needs. Therefore, InVesalius came as a proposal of development with the aim to be a medical software image analysis with null acquisition cost, capability of execution on low-cost personal computers and the capability of execution on different operating systems and act as a platform to encourage the use and development of medical images in Brazil.