The Ecopath International Initiative (EII) is a non-profit research organization based in Spain. The work is focused on contributing to the sustainability of living resources and ecosystems through the development, implementation, education and promotion of analytical tools and ecological modelling. Special emphasis is given to the use of the modelling approach Ecopath with Ecosim. EII closely collaborates with institutions in the fields of research, technology and education, in conjunction with the Ecopath Research and Development Consortium. This Consortium is a cooperative network focused on the research, development and sustainability of the Ecopath with Ecosim approach and software, its information basis, and complementary activities. In this way, the EII participates in research projects and software developments with partner institutes across the globe.