A distributed computing system includes at least first and second distinct computers each having a different operating system. First processes are compatible with the first operating system and second processes are compatible with the second operating system. A third scheduling computer, coupled to the first and second computer via a communication network, includes a scheduler for scheduling the first processes and the second processes to execute respectively on the first and second computers. The scheduler accesses a master schedule that defines an executing sequence of the first processes and the second processes. The master schedule can define conditional inter-relationships between the first processes and the second processes.