Both Microsoft and VMware have revamped their product suites, and therefore their licensing, once more. As always, how you buy will dictate how you license. It has taken a bit of time for all the revamped information to percolate through to each corporate site and for all the issues to be addressed. As we did before, let us look at licensing. We will look first at 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.