Upconn a tool that lets Unix programmers visually describe the connections between the processes in a distributed program and then execute the distributed program, is described. Upconn consists of several modules and can be extended by adding to a library of tools rather than by adding many special features to Upconn itself. Upconn has three main uses. First, it lets researchers study distributed processing in common Unix environments, reducing the dependence on specialized environments. Second, it can be used for rapid prototyping of distributed applications. Third, Upconn is a learning tool that can help students focus on writing distributed programs without dealing with the complexities of the communication links. >