VMware hasn't done much towards simplifying its licensing, but on the low end is its vSphere essentials price of $995 that supports three physical servers with two CPUs apiece.
Windows continues to have a variety of Windows guest license programs to complicate an already difficult situation.
And while both Xen Server and Hyper-V are free, the tools to manage them aren't and can quickly add up. What would be nice would be a single price and single license. But we aren't there yet.
Yet even aside from these three issues, there are still a few areas where the vendors differ:
Both Citrix and Microsoft are making an effort at managing other hypervisors, making it easier for IT workers, especially those whose shops that are going virtual in big ways.
Citrix sells two versions of its Essentials management software, one for its own Xen servers and one for Hyper-V. There are minor differences between the two versions, such as that Hyper-V lacks support for the high availability that is found in the Xen version. But both share common core components such as storage link snapshots and provisioning, workflow and procedures integration, dynamic VM provisioning and load balancing.
Microsoft's System Center currently will manage both VMware and its own hypervisors, and in the next release will also handle Xen's as well, making it the most pluralistic tool.
Meanwhile, VMware hasn't been idle either on the management front, and came out with a series of new tools that can help handle more complex virtual infrastructures under its vSphere v4 update in mid-2009. There is better support for fault tolerance, better support for moving running VMs between servers, and virtual network switches integrated into the management package. It also allows users to beef up RAM, storage, and CPU while a VM is running.
And third parties continue to enter this market as they see opportunities. Hytrust's appliance came out last spring, and continues to be enhanced to enable better security policies around VM image management.
The big three virtualization vendors have made some major strides toward Virtual Desktop Infrastructure in the past nine months. VDI refers to the ability to store boot images of desktops on a central storage repository, and send them to a thin client or other device to run.
This doesn't obviate the need for various third-party tools such as connection brokers and storage managers, but at least they are all moving in the right direction. Microsoft has the most improved among the three with its R2/Windows 7 combination of features (as we mentioned earlier) that make VDI implementation easier.
And VMware continues to enhance its series of management tools under its View line that include thin client agents, desktop management, connection brokers and more. They have come up with a new remote protocol called PC over IP that looks promising, too.