— In this paper we present a formal description of PROSA, a P2P resource management system heavily inspired by social networks. Social networks have been deeply studied in the last two decades in order to understand how communities of people arise and grow. It is a widely known result that networks of social relationships usually evolves to small–worlds, i.e. networks where nodes are strongly connected to neighbours and separated from all other nodes by a small amount of hops. This work shows that algorithms implemented into PROSA allow to obtain an efficient small–world P2P network. We also show how taking advantage of PROSA structure it is possible to effectively answer queries. In particular, the so–called query recall for PROSA is estimated and compared to that obtained in SETS [1] and GES [2].