In the Grid world users are organized into communities called Virtual Organizations (VOs). Currently, the Italian production Grid supports more than 50 VOs operating in different research areas such as High Energy Physics, Biology, Computational Chemistry, Bioinformatics, Earth Science, Astrophysics, etc. A comprehensive list of VOs supported in the Italian and European Grid can be found in the  Operations Portal provided by the European Grid Infrastrustruce at this link.