What you should be searching for is "Cluster."
The "Cloud" is basically shorthand for "my processes are the problem of some provider out on the internets." If you're doing it locally, you're doing clustering, and people have been doing it for the stuff you're talking about for a good while now. If you're selling that computing power to someone one on the internet, you're their cloud.
Popular clustering frameworks include Beowulf/Scyld, openMosix (no longer in development, but still used), OSCAR, or MPI
There are also distributed processing algorithms (i.e. Grid Computing, a term which is often used synonymously with "Cloud Computing") like those used for SETI@home, or Folding@Home. Both of those projects are currently running BOINC which is pretty nice.