On the fall and rise of the GNU GPL

In preparation for my presentation at OSBC tomorrow I’ve been looking back at some of the key trends that influenced the commercial open source landscape in 2009. One of those is the decline in the use of the GNU GPL as a proportion of all open source projects.

The decline was highlighted by figures from Black Duck Software in June 2009, which indicated a 5% decline in the use of the GPL, compared to the previous year.

At the time that reduction was put down to the move to Web applications and cloud computing, where the reciprocity of the GPL does not come in to play.

Looking at those figures again, and comparing them with the latest Black Duck numbers, I’m not convinced the answer is that simple. 50.06% of projects tracked by Black Duck in June 2009 were using the GPLv2, and that percentage has continued to decline, to 48.86% today.

However, a few quick calculations indicates that the number of projects using the GPLv2 has actually increased in real terms from 94,254 in June 2009 to 97,148 in March 2010. That 3% increase is less than the overall 6% increase in open source projects during the same period, but not alarmingly so.

If we assume that Web applications and cloud computing played a significant role in the proportional decline of the GPLv2, we would expect to see a significant rise in the use of the AGPLv3. While the use of the AGPLv3 has indeed risen 16% between June 2009 and today, in real terms the rise is from 198 projects to 231 – still an insignificant amount compared to the GPLv2.

Indeed the GPLv3 appears to be having a much more significant impact on the GPLv2, rising 14% from 9,541 in June 2009 to 10,887 in March 2010. Overall the use of the GPL family of licenses has risen 4.1% from 103,993 to 108,266.

To be clear, in the long-term I do still expect cloud computing and software services to have a negative impact on the use of the GPL, but it appears that we may have been a bit premature in seeing a causative link last year.

We have also pointed to increased use of more permissive licenses, either in order to encourage widespread adoption and rapid community formation, or to enable easier integration with proprietary software. And those are two key trends that we expect to see applying ongoing pressure on the GPL in the future.

Every time I write about licensing and community I am reminded that licensing is just one of a number of factors that can influence the health of an open source community. It is also true to say that the increased use of cloud and Web applications is just one of a number of factors that are influencing the health of the GNU GPL.

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#1 Chris Aniszczyk on 03.16.10 at 6:05 pm

I think that the GPL (strong copyleft) is on the decline. I blogged about my opinion recently that I expect to see a strong rise in weak copy left licenses like the LGPL and EPL [1]. My theory of how GPL was popular was because when people chose a license, they chose it based on their experiences. They probably heard of the kernel and knew that it was GPL therefore through it was good. Developers aren’t good with legal matters. Another theory I have is that when project hosting sites like SF.net first started out, GPL was one of the licenses generally pushed. I could be wrong, who knows. I just know I see a pattern when Eclipse, Symbian, Codeplex start offering weak copy left licenses.

[1] – http://aniszczyk.org/2010/02/08/eclipse-symbian-and-the-rise-of-the-weak-copyleft/

#2 Don Christie on 03.16.10 at 10:34 pm

At Catalyst we favour the GPL3 and AGPL for many reasons. However one important one is that to us it makes most commercial sense from a sustainability perspective. In picking third party software we prefer the GPL as it is a reasonable indicator that the project founders had thought about sustainability *and* their users rights.

#3 Anders Norgaard on 03.17.10 at 5:02 am

I think the percentage decline of FOSS projects under the GPL is a natural consequence of increased corporate participation in FOSS development. The GPL and share-alike provisions works great for communities of people who want to create something great.


Corporations and their lawyers and bureaucrats on the other hand are distrustful of anything they cant control, and are more likely to prioritize control over community – and go with something like an Apache license.

#4 Matthew Aslett on 03.17.10 at 8:56 am


I agree with your viewpoint, apart from the point about control and community. I agree GPL is great for true communities, but when it comes to vendor-led projects we have seen that the GPL, when used alongside copyright assignment policies to ensure that the vendor has control of the project, restricts community input. More permissive licenses give vendors control over the use of the output, *and* can also be used to quickly encourage community engagement.

#5 Aaron on 03.17.10 at 11:30 am

Predicting a GPL decline with cloud computing is not only bad science, but spurious since the GPL doesn’t place any of the restrictions implied here to so called “cloud computing”. The GPL never has even when cloud computing was previously called “software as a service”. This is the hole the AGPL is trying to fix.

The rise of permissive licenses over the GPL is from the usual level of paranoia and FUD, but is also the result of Enterprise software companies *distributing* their work with free software packages, libraries and frameworks.

The AGPL is slow to pickup on a wide scale, but that makes it more important that it should be promoted precisely because of the rise of so called “cloud computing”.

#6 Ecommerce on 03.25.10 at 9:02 am

We do find GPL3 and AGPL a lot more beneficial at our end due to the sustainable economic virtues it possesses.

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