Sun Microsystems is opening the door to backing the upcoming General Public Licence version 3.0 (GPL3).

Sun's chief open source officer, Simon Phipps, wrote in a blog posting that he would be "very surprised" if the final GPL3 was not an effective tool for some of the communities Sun sustains or will initiate in the future. 

"We are certainly not opposed to it, and it would be a huge mistake to read our use of the GPL2 that way," he wrote.

The remarks are the most outspoken endorsement for the licence by a commercial software vendor so far.

Sun is giving GPL3 added credibility after Linux creator Linus Torvalds denounced the licence for waging a religious battle against digital rights management technologies. 

Phipps stressed that it is too early to commit to the licence as it has not yet been finalised, but he praised its efforts to "neutralise the effect of software patents".

Sun released the first code of its desktop Java implementation earlier this month under the current GPL2. Phipps wrote his posting to counter speculation suggesting that the decision proved that it opposed GPL3.

A final version of the GPL3 is scheduled to be published by 15 March 2007.

The licence has gained added relevance in light of the Novell-Microsoft partnership, in which the two vendors agreed to licensing that provides a patent non-assertion covenant from Microsoft to Novell SuSE Linux users.

The patent deal has drawn sharp criticism from the open source community and prompted the authors of the GPL3 to change the licence to explicitly block the deal.

This strategy would also require current GPL2 projects that ship as part of Novell's Linux distribution to switch to the GPL3 when published.