Microsoft is giving away Windows Hyper-V Server 2008 R2 for free.  This is great news, as it is not only a competitor to VMWare Server, or open-source solutions like Sun’s VirtualBox, it’s also a freely distributable Windows environment!  Obviously, there are some restrictions on the license that would prevent you from using this as your primary desktop operating system (and Windows Server makes a terrible workstation, to be honest), but surely this will be useful for your testing and deployments!

Thanks to Alex Handy at SD Times.