With the pending launch of Microsoft's virtualization hypervisor, Hyper-V, in the next couple of months, battle lines are being drawn.

In Microsoft's corner is Citrix, a company that has become an important part the virtualization industry since it acquired open-source virtualization trailblazer XenSource. In the other corner is VMware, which is scrambling to take advantage of the time it has left to create a wider gap with its encroaching competitor.

Simon Crosby, the CTO of the Virtualization and Management Division at Citrix, can't wait for Hyper-V to arrive. "The sooner that happens, the better," he said.

Just like it has done in the past with server-based computing, Citrix will extend the Microsoft platform to make it more attractive, according to Crosby, without elaborating on what the company is working on. "We haven't made any product announcements yet, but we will as Microsoft goes to market," he said.

He also sees opportunities for Citrix running its products on top of Microsoft's Hyper-V, for example, the recently launched XenDesktop.

"Xen and Hyper-V share the same architecture," Crosby said. "Obviously, Hyper-V is a completely, independently created Microsoft implementation, but XenServer is 100 percent compatible with Hyper-V."

But Microsoft isn't doing everything right.

"It has to wrap its head around using Windows on appliances," Crosby said. "We keep nagging on them to do that. I think it will get there when it realizes how important it is for ISVs (independent software vendors)."

But when Microsoft finally launches its hypervisor, Crosby thinks it will take to the SME market pretty quickly.

In the meantime, VMware is doing its best to take advantage of Microsoft's absence, according to Crosby. However, "every large customer I talk to doesn't want to bet the farm on just one vendor," he said.

Just because Citrix hopes to do a lot of business on Hyper-V doesn't mean it is forgetting its own XenServer hypervisor. It will play an important role as Citrix makes a push into the data center automation market, Crosby said.

Crosby was one of the founders of XenSource, so both the product and the underlying open-source project known as Xen are close to his heart. Since the deal between Citrix and XenSource was finalized, 3,000 resellers have been educated on the platform, he said. It is also becoming an integrated part of servers.

"XenSource will be a point-of-sale option on 50 percent of X86 servers worldwide this year," Crosby said.

HP and Dell are already shipping XenServer, which will help it to attain bigger footprint. But that isn't the primary reason for getting the products integrated on hardware. Instead, it's a way to put pressure on software vendors who are slow in adding support for virtualization, according to Crosby.

"It really changes the certification game," Crosby said. "Are you going to tell HP you don't support their hardware?"

The Xen platform has also become the platform of choice for anyone -- including Sun, Red Hat, Oracle and Novell -- that want to be virtualization vendors.

The only company to incur Crosby's wrath is Oracle. The company has chosen a closed approach to virtualization, with its own version of Xen. Oracle only allows its own virtualization technology to be used with its applications, Crosby said, which is "silly."

Crosby wants the rest of the companies innovating with Xen to become to be successful as well. In the end, he is convinced virtualization hasn't found its final form yet.

"The Xen ecosystem hasn't really hit the market hard yet, but it will soon," Crosby said. "VMware is the most mature platform, but we are close behind."