Sun Microsystems will release its xVM Ops Center virtualisation management application under the General Public Licence version 3 (GPLv3), the company revealed at the Oracle OpenWorld conference in San Francisco.

The project marks the first application that Sun has put under the GPLv3.

Rich Green, executive vice president for software at Sun, told vnunet.com that the licence was a "first step", suggesting that the company could pick GPLv3 for other projects in the future.

Sun released Java under the second version of the GPL in 2006. GPLv3 was released earlier this year.

"We will continue to advance in lockstep with the GPL community," said Green. "It is a very important part of our strategy."

Sun has had some initial worries about GPLv3, but these had since been cleared up. "We now announce that we are fine. This enables us to go forward and make this first step," said Green.

The company had suggested that it may release OpenSolaris under the GPLv3. The operating system is currently governed by the open source Common Distribution and Development Licence.

Sun's xVM Ops Center allows firms to manage virtual servers in their data centres and is slated for release in December.

Administrators can set policies instructing the software to move an application to a different server in case of a hardware failure, for example.

Sun also is preparing xVM Server, a Xen-based virtualisation server that rivals VMware's ESX Server, Oracle VM and Linux operating systems with embedded hypervisors from vendors such as Red Hat and SuSE.

Sun's xVM server is based on a trimmed Solaris kernel, allowing guest operating systems to benefit from popular features such as the ZFS file system, network virtualisation or DTrace, which allows developers to optimise application performance.

Sun's virtualisation software will be available free of charge with support at a fee. Chief executive Jonathan Schwartz touted the cost as one of the main advantages of Sun's virtualisation platform over VMware's or Oracle's.

Oracle unveiled its own virtualisation server on 12 November. The space is dominated by VMware, which lit up the virtualisation market earlier this year with its initial public offering.

VMware is currently valued at $35bn, more than double Sun's $17bn. Green dismissed investor appetite for VMware stock, however, arguing that the virtualisation market is still young and that Sun would offer customers more value.