Server room menu: Server virtualization in four styles:

"...any user entertaining the idea of moving servers into a virtual world are best served by avoiding the urge to get caught up in the hype that will inevitably arrive throughout 2006. Instead, analysts advise that a critical evaluation of resources and an ironclad Grip on understanding the behavior of the server workloads and styles is necessary before they even utter the word virtualization."

TechTarget offers a rundown of the 4 main server virtualization competitors.