There is great virtual machine software out there, VMware, XEN, etc. VMware was one of the first I also dared to use for more serious environments, like for instance development environments. Triggered by my old friend Erwin Brinkhuis, he completely switched to Linux (in his case Ubuntu), I had a look at VirtualBox. This product has, IMHO, real potential to become a VMware contender. Currently it can be used on Linux and Windows, a OSX version is in the making.
