Choosing the Right Cluster System

ckotso asks: "So I've read here and there about linux clusters, and I am ready to set on creating one with some help of the educational institute I am working for. So far I've found out about Beowulf, SCI and MOSIX. I really wish I can get some help on this, since NT is making its way into the University gradually and I hate to see this. I want to give a cheap and robust alternative to this place, I simply have to change their minds! " Interested? There's more information inside.

"My questions are:

1. Have I missed any other serious competitor in the cluster field?
2. What are the pros and cons of these systems?
3. Has anyone tried them all and written any report as to how they compete?

Thanks!"