The GNU GPLv3 license, successor to the pervasive GPLv2 license, was published in June 2007. Following publication several discussions have sprung up regarding GPLv3 s interpretation as well as the perceived benefits and cons as compared with GPLv2. So why the debates and disagreements and is GPLv3 really important anyway?
Firstly one must consider GPLv3 in context to GPLv2. To date, GPLv2 licenses the vast majority, typically 60-70% of all FOSS (free and open source software) projects. Moreover the Linux kernel is licensed under GPLV2 and is used in increasing numbers of consumer electronics and mobile devices thus furthering proliferation of GPLv2. These attributes give GPLv2 a privileged position in the league of FOSS licenses. Therefore any successor license has the capacity to greatly impact the FOSS community.
Historically GPLv2 was a watershed when first published 16 years ago due to its copyleft properties. These intend that users of the license continue to receive the source code and derivatives of that GPLv2 covered code, thus preserving users freedom to run, copy, distribute, study, change and improve the software . As successful as it has been, GPLv2 has also attracted a certain amount of criticism. These criticisms concern the difficulty in interpreting the license due to the lack of formally defined terms, differing views about what makes a derivative work and ambiguous patent license grant.
In writing GPLv3, the FSF (Free Software Foundation and original publishers of GPLv2) set out to rectify these concerns as well as advance the license in light of contemporary themes of patents and digital rights management. Specifically GPLv3 introduces new terms regarding the DMCA (Digital Millennium Copyright Act), a new patent provision and new mechanisms for dealing with anti-Tivoisation. Firstly, the section titled Protecting Users Legal Rights from Anti-Circumvention Law is intended to prevent GPLv3-covered code from being included in technology or products that would be used to enforce the DMCA. Secondly, there is an explicit patent provision in GPLv3 but some argue that the wording used is not particularly clear or straightforward. Thirdly, the anti-Tivoisation section appears to place very specific additional obligations on users to provide source code and its installation information.
So what is the impact of these new terms? Is GPLv2 better than GPLv3? What are the differences? What are the similarities? If I were starting a FOSS Project now would I use GPLv2 or GPLv3? In our just published white paper titled GPLv2 versus GPLv3, The Two Seminal Open Source Licenses Their Roots, Consequences and Repercussions we explore these issues in detail. There are many issues that need to be considered in making such decisions and these criteria are explored and reviewed further in this paper.
The end of the road seems unlikely, particularly given that nearly 600 mature open source projects have already moved from GPLv2 to GPLv3, a transfer rate of about 10% of existing software projects (see Palamida’s website for more details). Additionally on the 10th September 2007 the Open Source Institute (OSI) announced their approval of GPLv3, thus providing formal endorsement of the license. Whilst time will only tell if GPLv3 continues the successful legacy of its predecessor we can for now analyse the issues and contemplate its future.
P.S. We are at the OSiM Conference in Madrid this week, come and speak to us if you are there also.