Linux.com: Building a Linux Supercomputer Using SSH and PVM

“If you have a couple of old Linux boxes sitting around, then
you’ve got the makings of a supercomputer. Dust them off, install
Secure Shell (SSH) and Parallel Virtual Machine (PVM), and start
your complex algorithms.

“All right, it’s not quite as simple as that. PVM handles only
the messaging between the machines. You must write your own
programs to actually do anything…”