In 2009-10, there was an intense debate between the co-creator of WordPress, Matt Mullenweg, and the founder of DIY Themes, Chris Pearson. The debate centered on whether or not Thesis needed to be 100% GPL licensed. Thesis lifted lines of code from the core of WordPress, which some people claimed made Thesis a derivative of WordPress. Pearson disagreed with the assessment which lead Mullenweg to insinuate he would take the matter to court.
Five years after that memorable debate, Richard Best of WP and Legal Stuff, has published a thorough analysis of WordPress themes, the GPL license, and what is a derivative work. His post is a breath of fresh air and the best I’ve read so far on the subject. Best doesn’t sell themes or plugins in the WordPress ecosystem giving him a neutral position to discuss the matter. He also has a legal background, but does not offer legal advice through his site.
Determining what defines a derivative work is complex, but according to Best, no one truly knows the answer to the question:
The reason we don’t truly know the answer is that the courts haven’t decided a case that is squarely on point (there are potentially analogous cases, of course, but – as far as I’m aware – no GPL or similar case directly on point). It is only the courts (in the absence of legislative intervention) that can finally determine the matter.
Courts might apply what some might say are orthodox notions of what it means for something to be a derivative work or they might incrementally (some might say dangerously) develop the law on this point but we just don’t know. And even if the courts of one country made a definitive ruling on the point, courts in other countries – where other lawsuits might be commenced – could decide differently. As a result, uncertainty remains.
The debate against Thesis never went to court, but it spawned several conversations throughout the WordPress community, like this one from Chip Bennett. This is why some people rallied for a court case to settle the matter once and for all. As far as WordPress is concerned, I think it’s unlikely a court case will ever take place.
Influence Instead of Lawyers
Mullenweg has other ways of influencing people to license their WordPress products 100% GPL which doesn’t require a lawyer. A good example is when Jake Caputo was banned from speaking or participating at WordCamps because he didn’t license his themes 100% GPL on ThemeForest.
After going back and forth in public debates, ThemeForest eventually added the ability for authors to choose between split-license and 100% GPL. After changing the license on all of his products to 100% GPL, Caputo was allowed to speak at WordCamps again. It’s this type of influence that prevents arguments from reaching the court system.
Only a Court Can Decide
There aren’t many posts these days debating the merits of GPL and WordPress. Best does a great job explaining why (emphasis mine):
I think the GPL/theme debate has reached the stage where it’s fair to say that a significant proportion of the WordPress community now frowns upon premium theme providers who either don’t GPL-license at all or (probably to a lesser extent) split-license their themes. That might not be good for business and that, for some, may be the bottom line.
For some people, this frowning may be caused by a particular view of what the GPL requires but for others – and I think this is a particularly important point – it may be caused by a recognition of the enormous opportunities that WordPress makes possible and the open source spirit and generosity that pervades much of the WordPress community. I think we’ve reached the stage where, for some people, this is more about a community norm than it is about a strict reading of the GPL (not to mention the tedium of listening to more and more competing GPL arguments when, ultimately, only a court can decide).
If a debate like the one in 2010 were to happen again, I think we’d see a huge outcry from every corner of the community for a court case to settle the matter. After all, without that, everything else is a moot point, right? If you sell commercial WordPress themes and plugins, I highly encourage you to read his post. Also read his thoughts on a somewhat related topic, the assumptions of GPL and automatic inheritance.