Sun Microsystems (NASDAQ: JAVA) announced a major upgrade today of its Virtual Desktop Infrastructure software. VDI 2.0, available now, supports a range of operating systems (Windows XP and Vista, Linux, Mac OS X, Solaris and Windows Mobile) and works with PCs and Macs as well as Sun's own Sun Ray thin client.

Price is $149 per concurrent user with one year of service, and a free trial download is available.

While competing with other virtualization players, Sun said it's reached an agreement with market leader VMware (NYSE: VMW) to run on the VMware Infrastructure 3 software to host Windows virtual machines (define), or VMs.

In VDI 2.0 Sun has added what it calls a virtual desktop connector that lets it use native protocols to give users access to Windows, Linux and Solaris. "We don't pipe them to the client device but leverage the server in the middle to get a high-quality connection," Chris Kawalek, product line manager for desktop and virtualization marketing at Sun, told InternetNews.com.

Kawalek said organizations that already have VMware can further leverage Sun's VDI 2.0 for better management of virtual resources. "You can statically or dynamically control the life cycle of machines," Kawalek said.

One example, temporary workers might be given a fixed length of access, like the 30 days of a contract, to give IT better control and resource management. Kawalek said IT could also use VDI 2.0 to set up specific users' VM to refresh to a known "good state" after they log out each day to insure any viruses or questionable software picked up while Web surfing is mitigated.

While VDI 2.0 runs on conventional PC or Mac hardware, Sun also has its own line of thin client devices called Sun Ray. "Basically we support any PC with a java-enabled browser so you can freely move your desktop environment to different hardware and have a similar experience," Kawalek said. "The key thing is we offer you choice."

That choice was just what Jeff Harvey, project lead for desktop infrastructure at Cincinnati Bell, was looking for. A beta customer for VDI 2.0, Cincinnati Bell has about 4,000 employees mostly running Windows 2000 on "fat client" PCs.

"All our mission-critical applications run on Sun iron, so we've looked closely at the thin client (Sun Ray)," Harvey told InternetNews.com.

But the company didn't want to dump PCs that were still on lease terms. "Now with VDI 2.0, we can wait till the last hour of the lease and drop in a Sun Ray," he said. "It'll look the same as the desktop PC to the users, and we'll get better utilization of our resources."

Sun has been ramping up its virtualization efforts of late. Last month the company released its new xVM Ops Center, a management tool for datacenters that can manage both physical and virtual servers.