Early next week, the Free Software Foundation is launching the consultation process which will lead to the release of version 3 of the GNU General Public Licence (GPL), one of the founding documents of free software.

Richard Stallman wrote it back in 1989 to embody the idea of "copyleft".

Copyleft is a hack on copyright; instead of using copyright law to restrict how you can copy and share a program, it uses it to guarantee the right to do so. The GPL is a copyright licence which makes sure that all recipients of the program, or modified versions of it, have as many rights as were originally given out. No one can take the code and release an improved version while keeping the source code to their improvements private. It's a legal embodiment of "share and share alike".

Today, approximately 70 per cent of the thousands of free software projects in the world are released under the GPL. Almost every free software hacker has some code somewhere licensed under GPL version 2 "or any later version". So changing the terms of the licence has great potential to upset people and fragment the community.

At present, there is reasonable coherence around what freedoms make up the "free" in free software – although there is significant disagreement about why you would want them. The Free Software Foundation's four freedoms, the Open Source Initiative's Definition and the Debian Free Software Guidelines, on which the OSI version is based, all include or exclude broadly the same set of licences.

However, there are contentious issues on the horizon.

The first is software patents. Although the software community in Europe has managed to see off software patents for the time being, in the United States it is still possible to lock up ideas and techniques for a 20-year stretch. Some argue that the only way to deal with this issue permanently is with the licensing equivalent of Article V of the NATO treaty (collective self-defence) – a clause which removes your right to distribute any GPLed software if you assert a patent claim against a single piece. Large software companies would then have to choose whether to continue using GPLed code to support their product offerings, or to reserve the right to litigate for patent infringement. There would be no middle ground here - such a move would certainly draw the battle lines. But others believe that copyright licences should not contain clauses regarding different branches of law such as patents or trademarks.

The second question is that of web applications. The purpose of software freedom is to make sure that all computer users have the opportunity to run, study, improve and redistribute the software they use. Today, however, many people use software via a web browser – webmail, search and mapping applications on websites. Even if those applications are built on GPLed software, the user does not have any of the software freedoms the GPL is supposed to grant them. Should the GPL force the availability of source code in this situation? Some developers who are locked out of changes to code they originally wrote say "Yes"; large web application companies such as Google and Yahoo may well think differently. Other free software hackers say such a requirement is completely incompatible with the idea of freedom. So opinions vary on how, if at all, the new terms should address these issues.

The GPL is the foundation stone of free software, and when you change the foundations of any edifice there's a strong risk of structural damage. If the community is split by the new licensing terms, projects may fracture into two versions (one with the new licence and one with the old) and a lot of time and effort will be wasted. The success of GPL v3, and the continued unity of the Free Software movement, will ultimately depend on whether the Free Software Foundation can produce harmony from the current discord.

Gervase Markham works for the Mozilla Foundation, a non-profit organisation dedicated to promoting choice and innovation on the internet. His blog is Hacking For Christ

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