My main research interests regard the formal description of interaction in computational systems and theories and tools for reasoning about such descriptions. This stream of research spawns form Theoretical Computer Science, Concurrency Theory in particular. I have also studied practical applications to Software Composition, Security and, more recently, Systems Biology. This approach starts form a ‘computational’ interpretation of the (living) systems, seen as composed by a large number of autonomous and interacting entities. On the long term this research line aims to provide significant models of systems, such as the biological ones or those composed by multitudes of individuals like crowds. These models can then be used as ‘virtual labs’ where the various hypotheses about the functioning of the systems can be investigated, ideally with less efforts than those required, for instance, by validation in vitro or in vivo.