[snowyskiesau]

Just to add to gary's post:

VMware does have a number of free versions of its software.

VMserver - this allows you to create and run VMware sessions/appliances. It has a web based management console.
VMplayer - this allows you to run sessions/appliances but does not have the ability to create a new installation (there is a free web based tool that get's around this restriction)

I only run Linux on my servers at home but use Vmware if I have something I need to run under Windows. (CAD mostly). I've been running VMware Workstation (not free) for about 7 years and it would have to be the best piece of software I';ve ever bought.