With Windows, OS X and Linux all running on x86 processors, it is only natural to want to run all the OSs on the same hardware.
So far, in my experience, VirtualBox is the easiest to use for this task.
Copying Virtual Machine Images
Of course, once you have VMs, the one the most time saving task is to be able to take a snapshot / image of a machine and deploy it all over w/o having to install from scratch. The few issues to keep in mind:
- hostname / machine identity