Celery is an open source asynchronous task queue/job queue based on distributed message passing. It is focused on real-time operation, but supports scheduling as well.
The execution units, called tasks, are executed concurrently on a single or more worker servers. Tasks can execute asynchronously (in the background) or synchronously (wait until ready).
Celery is already used in production to process millions of tasks a day.
Celery is written in Python, but the protocol can be implemented in any language. It can also operate with other languages using webhooks.
That should help implement master/worker style parallel computing.