FSF has been implemented in two contrasting POSIX compliant real-time operating systems, MaffRTE and Shffark, which are based on fixed priority and EDF scheduling schemes, respectively, thus illustrating the platform independence of the presented approach. The implementation has proved to be feasible, efficient, and easy to use. It has been successfully used to implement a distributed controller for an industrial robot, a multimedia application, and an artificial intelligence application controlling a team of soccer robots. These implementations and case studies have shown that FSF can be implemented efficiently with moderate effort, is effective and easy to use from the application, and can be used in distributed systems both in the processors and in the network. Both implementations are available as free software from their respective operating system web pages.