Sun Microsystems, long a thin client advocate, says its Virtual Desktop Infrastructure 2.0 software can deliver whatever style of desktop that users want.

In its 2.0 version of VDI, it's adding a Desktop Connector, a server that sits between the centralized source of virtual machines and end users applying for a desktop.

As a matter of fact, Sun isn't seeking to be the generator of the virtual desktops but the broker of access to them. It's focused on being able to deliver a Windows, Mac, Linux, or Solaris full screen presentation to the end user over the network. And it can add its own thin client, the Sun Ray, to that line-up, giving enterprises the option of saving on the expense of end user machines.

The Sun approach, however, works in conjunction with, not in place of, VMware's Virtual Infrastructure 3, which includes the ESX Server hypervisor to generate virtual machines.

Sun's Desktop Connector in its VDI 2.0 is somewhat analogous to Citrix Systems Connection Broker, which doesn't generate virtualized applications but manages the requests from hundreds or thousands of end users for application services, said Chris Kawalek, product line manager for Sun's desktop and virtual software marketing.

Sun's VDI 2.0 allows administrators to order up pools of virtual machines from VMware's Virtual Infrastructure 3 installations, then deploys them to users in a more dynamic manner than VMware can, said Kawalek. In effect, Windows XP or Windows Vista desktop virtual machines are generated, but Sun can translate them into the end user's desktop presentation of choice, he said in an interview.

The approach reflects a partnership announced by Sun and VMware in February, and lead to the rapid modification of Sun's initial release of desktop virtualization 1.0 last October. Sun charges $149 per concurrent user for its VDI 2.0 software.

Through VDI 2.0, different groups of users can be identified and equipped with the desktop of their choice. Both accounting and call center users may want a Windows desktop, but the accountants want a different set of applications on theirs, he said. That's possible with the VMware/Sun VDI combination. And with centralized virtual machines, "having a thin client is a good thing," he added, something mere virtualization vendors cannot provide.