The paper reports the development of a software platform, named PES (Parallelized Evolution System), that parallelizes the fitness evaluations of evolutionary methods over multiple computers connected via a network. The platform creates an infrastructure that allows the dispatching of fitness. evaluations onto a group of computers, running both Windows or Linux operating systems, parallelizing the evolutionary process. PES is based on the PVM (Parallel Virtual Machine) library and consists of two components; (1) a server component, named PES-Server, that executes the basic evolutionary method, the management of the communication with the client computers, and (2) a client component, named PES-Client, that executes programs to evaluate a single individual and return the fitness back to the server. Performance of PES is tested for the problem of evolving behaviors for a swarm of mobile robots simulated as physics-based models, and the speed-up characteristics are analyzed.