SYNTHESIS is a tool for automatically assembling correct and distributed component-based systems. In our context, a system is correct when it is deadlock-free and performs only specified component interactions. In order to automatically synthesize the correct composition code, SYNTHESIS takes as input an high-level behavioural description for each component that must form the system to be built and a specification of the component interactions that must be enforced in the system. The automatically derived composition code is implemented as a set of distributed component wrappers that cooperatively interact with each other and with their wrapped components in order to prevent possible deadlocks and make the composed system exhibit only the specified interactions. The current version of SYNTHESIS supports two possible development platforms: Microsoft COM/DCOM, and EJB (Enterprise Java Beans).