Both Microsoft and VMware have revamped their product suites and therefore their licensing once more and how you buy will dictate how you license (as always). It has taken a bit of time for all the information to percolate through to each corporate site and all the issues to be addressed. As we did before, let us look at licensing. We will look at first the old model of Hyper-V vs VMware vSphere vs Citrix Xen vs RedHat KVM. Then in a follow-on article we will look at the new cloud suite models.