I have about 4 older computers lying around my house, being mostly unproductive. I would like to breathe new life into them by creating a computer cluster out of it. I have a friend who had done it, and managed some respectable results out of it, and I would like to do the same. They are not all the same processor power, and certainly to the same extent not the same RAM. If anyone could point me in the right direction of putting together a cluster, that would be great. I know how to use basic things, Linux doesn't scare me, I just need some good software and a how-to and what computer clusters of my interest can/can't do. I would really appreciate it, I dreadfully hate seeing good computers rot into nothing.