Whoa, I was just talking about OpenMOSIX the other day - at my college job, when we retired workstations, they would just sit in the back closet for years until facilities would get around to getting them up for auction. We set up a TFTP boot setup and had a few dozen nodes at any given time. It wasn't high performance by any fashion, but it worked pretty transparently and was always fun to throw heavy synthetic workloads at it and watch the cluster rebalance and hear the fans spin up on the clunky old pentium's.