We currently have 21 Dell blades with RHEL 5 and WMVware ESX suite installed. Now we have over 110 VMware guests running and growing, ranging from Windows server to Linux to FreeBSD. »

Same goes for Innotek VirtualBox, like VirtualPC 2007, it works great and hardly takes up any of ram or resources. You can install VirtualBox on Windows, Linux, Mac OSX, and OpenSolaris hosts. Plus VirtualBox is free. See Innotek VirtualBox for more information. »