"The Citrix philosophy is one of being hypervisor-agnostic," Dholakia said. "We're betting a big part of our business that customers will prefer hypervisor-agnostic virtualization solutions. You're going to see increasing pressure from the marketplace that there's not going to be a one-vendor solution for the entire market."
It was a tough decision to include VMware support in the Citrix desktop product, according to Sumit Dhawan, Citrix's desktop delivery product marketing director.
"We would of course prefer if customers used our stack throughout, but we have to take into account what our customers have," he said.
SMS Pro Tech, a Citrix partner in Sidney, Ohio, will encourage its Citrix desktop virtualization customers to migrate other virtualization products from VMware, marketing manager Kathy Vogler said -- but it will take time, because the desktop virtualization solutions market is still very young. Gartner does not expect mainstream adoption to hit until 2010.
"Customers seem to be very knowledgeable about [desktop virtualization], but there's some hesitancy," Vogler said. "Everyone knows this is where it's eventually headed."
Dholakia agreed that mainstream desktop virtualization adoption will happen, although it's unclear when.
"It's a tremendously powerful technology," he said. "To date, most of our focus and the market's focus has been on server virtualization. You're really starting to see ways in which you can leverage desktop virtualization."
VMware is the virtualization market leader, so Citrix would have limited its XenDesktop customer base by not supporting it. The hope is that VMware customers buy XenDesktop, like it, and decide to move their other virtualization products from VMware to Citrix.
"Over time we can show our customers the value of Xen," Dhawan said.
Dhawan described VMware as Citrix's "prime competitor," while he called Microsoft a "top partner" -- even though Microsoft is also moving more and more into the virtualization market. VMware has used that dichotomy to try to drive a wedge between Microsoft and Citrix and stave off competition from both companies.
XenDesktop is the successor to Citrix Desktop Server, which "hasn't really taken off," Dhawan said. High storage costs were one of the biggest problems for Citrix Desktop Server customers, but XenDesktop addresses that issue, he said.
XenDesktop does not store images of every user's desktop in the data center. Instead, it stores separate images of the operating system (OS), applications and user settings, then assembles a user's desktop when he or she logs on.
The OS and applications are the same for every user, so XenDesktop does not need to store multiple images, and that reduces storage costs, Dhawan said. Since XenDesktop rebuilds the desktop each time a user signs on, it also improves computing performance, he said.
Most of Citrix's XenDesktop business is expected to come from channel partners selling perpetual licenses. Subscription licenses are also available for partners who would like to offer managed or hosted desktop services, but "Desktop as a Service is a fairly new concept," Dhawan said.
XenDesktop starts at $75 per concurrent user, and it will ship May 20.