Matt Mullenweg is Wrong. Thesis Should Carry Whatever License It Wants.

There is a debate underway about the legality of Thesis, a popular, paid for WordPress theme, using a different license than the one WordPress uses, which is the GPL. Matt Mullenweg, founder of WordPress, contends that all themes for the platform should inherit the WordPress license and should be considered a part of the platform. Chris Pearson, creator of Thesis, obviously has a different opinion. There have been many heated debates over the topic, but I haven’t heard an argument by either side that is compelling one way or the other.

My opinion, which I obviously think is compelling, though is not in any way rooted in any facet of the law or articulated in any legalese whatsoever, is that Matt Mullenweg is wrong. I love what Matt has done. I use and love the WordPress platform. I also think that his position is noble and rooted in the greater good for the WordPress community and open source in general.

I think what has been overlooked in his argument is an assumption we have about software, namely how it is supposed to work and what defines working software in relation to a pluggable software stack, such as WordPress. Technically, I could create an empty my-new-index.php file, place it inside the WordPress directory structure, and I have extended the platform. According to Matt, my software which does nothing, must inherit the WordPress license. Now if I want to sell (or redistribute) this do nothing piece of software for $50.00 (available upon request) I must also sell it with the GPL license. So technically, any piece of PHP code can placed inside of the WordPress directory structure and therefore, all PHP code must also carry the WordPress license!?!

There is obviously some rational limit and discretion available to us so that this sort of thing won’t ever happen!  We could say because the Thesis theme makes use of the WordPress API, it must be intended for use with WordPress. However, the WordPress API is a bunch of PHP functions and WordPress  itself uses the PHP API, which carries a different license (The PHP License). Which one takes precedence (if they were conflicting) ? Do all PHP applications, because they all must, by definition, use the PHP API, have to inherit the PHP License? This would be ridiculous and I’ve never seen a PHP app with the PHP license, so clearly using an API can’t include licensing requirements, so long as you aren’t modifying and redistributing the original API itself. For example, if I use a PEAR class, I don’t have to inherit the license for all of my work, I just can’t change the license of that class and or modify the original code without making it available again.  Thesis doesn’t (to my knowledge) modify or extend any of the WordPress core. It provides interface enhancements, outputted HTML generated not by WordPress, but by Thesis. WordPress just consumes the Thesis software because it exists in a certain location, placed by someone into the WordPress directory structure.

This is the nature of pluggable systems, or software stacks. They are meant to be interoperable with other pieces of software whose parts and purposes are not known ahead of time. This covers a lot of space, space that isn’t even in existence and which it would, if Matt were correct, claim licensing rights to, in the event “it” comes into existence and “works” with said piece of software. Clearly Thesis “works” with WordPress. But so does a blank file. I intend for that file to do nothing, and it performs (quite efficiently) that task!

At the end of the day, it is only because Thesis is marketed to the WordPress community and is intended to be used with the WordPress platform, that there is an argument about how the software should be licensed. But Thesis is not sold bundled with WordPress, nor is anyone who purchases it required to use it with WordPress. For all intents and purposes, it is a stand alone piece of code, that well, does nothing important or worthwhile. Can you really license functionality that may or may not exist depending on how the purchaser decides to implement their purchase, just like my overpriced(though well worth the investment), blank PHP file could be used in any PHP application?

I have a lot of questions (I haven’t read all the licenses either, so I may be in total error :). Though from what I’ve read and heard so far, it is only because we have an expectation of how the software will work when it is in the WordPress directory structure that there is a conflict with how Chris has licensed Thesis. This expectation is set by the marketing of the software, not necessarily the software itself. Aside from Trademark infringement, does the language used to sell a product carry over into the the actual license the code must carry? This wouldn’t make sense. Say for instance, “Runs on Windows”, would require another license too?

I think we’re going to see a lot more arguments over licensing conflicts like what we’re seeing with WordPress/Thesis. Software is the biggest it has ever been. Open Source software is integrated into the business world like never before and business models are built on top of many of the various projects which are out there, “free” to use. As this space expands, no doubt more and more gray areas will as well.

On a practical note, what would stop Chris from writing a simple wrapper around the WordPress API his files use, license this with the GPL, use his wrapper functions instead from inside Thesis and then keep the current Thesis license?