Citrix also offers XenServer which can be ran independently or tightly integrated with Microsoft's Hyper-V. We currently use both Citrix XenServer and VMware in our environment and as an end user of the system, my experiences have been comparable on both systems.

I know that Citrix and Microsoft have a close business relationship and I think Microsoft even allowed Citrix access to much of the Windows source code. This gives Citrix a clear advantage with allowing them to tailor their products with Microsoft's.

What will the Microsoft/Citrix partnership speel out for VMware? :w00t: Well, there's some debate about whether or not VMware will be able to compete with XenServer & Hyper-V. The Register published an article last February (Citrix undercuts VMware with XenServer giveaway[/url]) that goes more in depth on the topic.

In my opinion, I think VMware will probably be able to stay in the game. I think the Citrix/Microsoft's tag team efforts against VMware is going definitely going to put a real hurt on VMware's market share though.