4 Macs if you include my wife's one! At the moment I am running with Tiger, haven't upgraded to Leopard yet , still sitting on the fence at the mo. I am looking in to building a Linux box for Maya but need to get some pennies together first. I was looking at the MacPro, but don't like the graphic card options. I'm still doing my research on the Linux front. I decided to drop windows due to a catastrophic crash that resulted in the loss of about 1000 images (about 2 years work), which as a result of a virus, went over to Macs due to better virus protection. So for me it's gonna be either Mac or Linux or both even. But I think I will start a new thread on this one as it not really relevant to this thread. Cheers Chris