The Free Software Foundation (FSF) has released the fourth or "last-call" draft of the third version of its GNU general public licence.
The organisation has also set a date for official publication of the licence, and laid out reasons why the free and open source software community should adopt GPLv3 sooner rather than later.
The GPL gives users the right to freely study, copy, modify, reuse, share and redistribute software. Created by Richard Stallman in 1989 for the GNU free operating system project, the licence was last fully revised 16 years ago as GPLv2.
The FSF also published an essay by Stallman extolling the benefits of moving from GPLv2 to GPLv3.
The new licence deals with issues that have emerged recently, notably the patent licensing deal signed between Novell and Microsoft in November. Parts of the Linux operating system, including its kernel, are licensed under GPLv2.
Earlier this month, Microsoft executives created a firestorm of protest in the open source community when they claimed that Linux and other open source software infringed 235 of the software vendor's patents.
"Microsoft made a few mistakes in the Novell-Microsoft deal, and GPLv3 is designed to turn them against Microsoft, extending that limited patent protection to the whole community," Stallman wrote. "In order to take advantage of this, programs need to use GPLv3." Software distributors who make discriminatory patent deals after March 28, 2007, may not pass on to others software covered under GPLv3.
Ultimately, the FSF would like to do away with software patents altogether, but realises that is currently impossible, aiming instead with GPLv3 to ensure free software can't be made proprietary through patents, according to Stallman.