PHP source code is compiled by the PHP compiler into a program, which is then run through the server's CPU by Apache. This produces output, which can be a combination of Content, HTML, CSS, or JavaScript. This output is under the copyright of the website author and totally different / seperate in terms of ownership with respect to the source code that lead to it's creation.

My theme generates its CSS files, which means that the CSS the visitors get is not part of the source code.

Dan Cole, WordPress Theme Developer.

I'm still unsure what this explanation has to do with determining whether or not a CSS file has been conveyed by being served by a web server, and then downloaded.

Then again, I'm reading before coffee. I'm going to go make some, and then re-read your posts later...

@chip_bennett | chipbennett.net (est. 2000) | WordPress user since May, 2005 | Linux (Kubuntu) user since September, 2007
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I'm sorry, I've been busy and unable to get on the internet for a week or so. Fact of the matter is that the World Championship BBQ Festival comes first above all things. ;)

No matter is ever really resolved definitively until a court hears it. Nevertheless, the GPL is a solid legal document with a fair amount of court cases supporting it in many contexts. I invite you to ask the EFF or a qualified open-source attorney what they think of the matter.

I do not speak for Automattic, however:

1. Is the image part of the theme? Will the theme function properly without it? If it's part of the theme, and any of the rest of the theme is covered by GPL, then the image is too.

2. Ditto CSS, with the added bonus that CSS files must conform to a specification defined by WordPress that makes the file a "theme" in WordPress' eyes. Furthermore, there are (somewhat poorly defined) standards that must be included in a theme for WordPress to function properly with that theme. Naming conventions and such, basically.

3. PHP files included in a WordPress theme must necessarily make calls to internal WordPress functions in order to display the bits like posts, titles, so forth. These are so-called "deep" calls to WordPress' own functions, and force the PHP file to incur the licensing requirements. Look at it this way: if you use a GPL library in your conventional C++ program, then you must follow the guidelines of the GPL. This is, in fact, why the Lesser GPL (LGPL) was created originally, because of this "library" problem. In this same manner, WordPress is the library of functions that your theme is making calls to. Therefore, your theme must be GPL as well.

Everything written can be copyrighted. This post, for example, falls under US Copyright Law (copyright 2009, me) by mere virtue of the fact that I wrote it. Your own post is copyrightten, in fact, and by quoting it, technically I am breaking copyright law. However, the fair use provisions allow me to quote it, since I am using it in the purposes of commentary and such.

Again, in what way do you determine that the images are seperate works from the theme itself? Are you absolutely certain that a court would agree with you? Because I'm never absolutely certain what a court will do. ;)

True, in that the law is never cut-and-dry or black and white. It simply doesn't work that way.

However, there is a lot of very good reason to suspect that their license is not only valid, but also enforcable. There's a lot of good legal arguments backing it up, and not very many good legal arguments against it.

Note: I am not a lawyer, this is not legal advice.


I fail to see it as "censorship". They're not actively blocking anybody from doing anything. They're just choosing who they will support and promote, and they're choosing the people that agree with them. That's not "censorship".

Plus, there is one almighty important fact here: wordpress.org is their site. They can do as they like with it.


As far as I'm concerned, it goes all the way. The GPL is a straightforwardly written document and the intent is extremely clear. Free software is its goal.

Okay, so "themes must be GPL, period" is more of a declarative statement than a conversation, but I don't see any room at all to bend on this one.

We're talking about legal aspects here, and the law is not as technical as computers and computer users are. The law is flexible. Intent matters.

The mere act of transferring the CSS file to a users browser is different than transferring them a copy of the theme for use on their own website. Even if there's no actual technical difference between the files, the intent is different, and in the eyes of the legal system, that difference matters.

Well, certainly no disagreement, there - except that you didn't share. ;)

I'm also not arguing the validity or enforceability of the GPL. There is, in fact, actual legal precedent for both. Rather, I am arguing the applicability of GPL to certain files.

The GPL only stipulates that it must apply to derivative works.

I believe you have the issue of applicability backwards here. The issue isn't whether or not the theme would function (properly or otherwise) without the image, but rather whether or not the image can function without the theme. (From my also-non-lawyer reading of the GPL, the license is pretty clear on this point.)

In image file certainly doesn't depend on a WordPress theme to exist or to function; therefore, it isn't a derivative work and the GPL neither imposes nor claims to impose applicability upon an image file in a theme, merely because of its inclusion.

WordPress does not define the specification to which CSS files must conform; rather, the W3C defines this specification. Likewise with images, a CSS file does not depend upon a WordPress theme to exist or to function; therefore, it isn't a derivative work and the GPL neither imposes nor claims to impose applicability upon a CSS file in a theme, merely because of its inclusion.

I agree completely that any PHP file that calls a WordPress-defined function falls under the WordPress GPL.

Again, not really true. Some examples:

"The sky is blue."
"The first president of the United States was George Washington."
"Chip Bennett"

Since "fair use" is a vaild defense against a copyright infringement claim - even though it must be proven - you're not "breaking [US] copyright law" by quoting.

This one is easy: I determine that images are separate works from the theme itself (in the context of the GPL) by virtue of all files in a theme being separate works.

A theme isn't a compiled program but rather a collection of individual files. Thus, one cannot treat such a collection of individual files the same way as a compiled program. Each individual file must be considered with respect to GPL applicability.

I am fully confident that a competent lawyer can easily prove that an image file in no way meets the GPL's definition of "derivative work"; therefore, I am fully confident that a court would agree with me on the matter.

Again, the issue isn't validity or enforceability of GPL, but rather its applicability to non-derivative works.

Automattic/Matt are fully within their rights to do as they like with wordpress.org; I'm not arguing that point. However, the Theme Repository is ithe definitive source for WordPress themes.

Disallowing certain themes from the repository is a form of csensorship. Certainly, some censorship is good; censoring spam themes benefits the community.

The question, though, is whether or not it benefits the community to censor perfectly valid, fully GPL-compliant themes simply because the author supports/condones the existence of non-GPL themes.

Also, I do not think that Automattic/Matt can claim that WordPress is a community project, and that wordpress.org is the WordPress community website, while at the same time making such decisions completely devoid of community input. It is not a matter of right or authority, but rather of appropriateness.

The GPL is also very clear on the limits of its applicability, and what it considers to be a derivative work.

I think, hopefully, I've explained the ample bend-room on the issue.

And what if someone creates an image, or develops a CSS file, and then puts that file into a theme? What if that person then conveys that file - not the theme, but just the individual file - to someone else?

Is that image/CSS file still "infected" (not my choice of wording, but can't think of anything equally descriptive) by the theme's GPL?

Further, if the person to whom that image/CSS file was conveyed then puts that file into another web site, or a theme for some other work that isn't GPLed (say, Drupal), does that otherwise non-GPL theme become "infected" by the WordPress theme's GPL?

Clearly, the answer to both questions is "no" - and I am fully confident that any court in the country would conclude the same.

@chip_bennett | chipbennett.net (est. 2000) | WordPress user since May, 2005 | Linux (Kubuntu) user since September, 2007
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"A theme isn't a compiled program but rather a collection of individual files. Thus, one cannot treat such a collection of individual files the same way as a compiled program. Each individual file must be considered with respect to GPL applicability."

Is this on gnu.org somewhere? I can find where it says that an add-on that requires the parent software to run must inherit its GPL license. I can't find where, if its made up of multiple files, each file definitely will have its own standards of applicability to be considered.



"Also, I do not think that Automattic/Matt can claim that WordPress is a community project, and that wordpress.org is the WordPress community website, while at the same time making such decisions completely devoid of community input. It is not a matter of right or authority, but rather of appropriateness."

WordPress is a community project. It's owned by Automattic, just like MySQL is owned by Sun Microsystems. MySQL is definitely a community project, with most of it's development being contributed by unpaid volunteers. 99% of new code in WordPress comes from unpaid volunteers in the community.
wordpress.org is owned by Matt, however he has almost no involvement with it. Otto and a few other unpaid non-Automattic employees do most of its management. It is definitely a community driven site.

WordPress is one of many open source projects which are mostly developed by their communities, yet overseen by the company that owns them. Some entity has to be the executor for the project, and its website, and since Matt created WordPress, that entity is Automattic. This is very common among large open source projects.


Right now Jeff handles 99% of the administration for wptavern.com and wptavern.com/forum with a little help from the moderators. If this site grows, the day may come when he has very little to do with it's day to day administration, and it may become a largely community driven site, much like wordpress.org is, thanks to people like Otto, who dedicate a large amount of their time.
Even if that day comes, Jeff will still make command decisions about certain content that will be banned from this site. Some people will not agree with his decisions, but that won't make it a non-community driven site.

For what shall it profit a man, if he shall gain the whole world, and lose his own soul?

Define "work". What is the "work" in question? Are you distributing the image files separately? Do you ever refer to them as being part of the theme?

Your argument here is facetious on the face of it. You put the images into the theme, the PHP files refer to them, the CSS files refer to them. If they were removed, the theme as a whole would be incomplete. The images are part of the theme, and the GPL applies to the whole work, not just parts of it.

The comment at the top of the CSS file must take a specific form in order for the theme to be a WordPress theme. The file must be named "style.css". There must exist specific classes in the CSS for things like captioning and image alignment to work correctly.

Don't be so literal.

You keep treating your theme as a collection of unrelated and independant files. Copyright applies to entire works.

Merely by virtue of the fact that there's a technical separation (a file) does not also imply that there's a legal one. Would you suggest that each page of a book is an independant copyright simply because they are on different pages?


Your own statement makes no sense. It's a valid defense. If it doesn't break the law, what are you defending against? ;)


Why? Why make this arbitrary and meaningless separation? What is your basis in copyright law for believing that two files cannot be part of the same "work"?

Virtually all programs are made of dozens or hundreds of independant files, and yet they are all a single work. The Linux kernal is a single work having thousands of files of all types. And the work as a whole is GPL'd.

The theme is the work. Separating those files into individual works serves no purpose in most cases. The files only have value when they are together as one whole thing. You made them together, I assume. You made them with knowledge of each other. You make a theme, you don't make a bunch of files.

I am fully confident that you are deluding yourself in some way.

Also, the GPL does not define the term "derivative work". That's defined by the court system and copyright law.

The GPL is not applicable to non-derivative works, obviously, because no license is applicable in such a case.

That's a different debate altogether.

I agree on that point, even though I support their decision in this matter.


Yes, actually it is, but I fail to see what the point of conveying individual images or files from themes would be. The theme is worthless in pieces.

However, be clear about who is doing this creation and distribution. If you created the image, you can license it however you like. It's yours. You own the copyright. You can then relicense it differently under another work if you so choose. It's only other people that cannot change your licensing terms.


Three problems with this statement.
a) I do not believe that it is legal for any WordPress theme to be non-GPL. It is a clear license violation.
b) Drupal is GPL'd: http://api.drupal.org/api/file/LICENSE.txt/7
c) Assuming your statement made sense in that respect, then yes, such another program would be required to abide by the GPL in a "viral" manner. GPL'd images is a topic of much debate in many places on the tubes.

Courts have already disagreed with you. Many projects have removed GPL'd images from their sources because of this issue in the past. However, for these cases, there exist GPL compatible licenses specifically for images that can be used instead. The LGPL has also been successfully used in this regard. I believe that the FSF currently recommends using the Free Art License for images, but I'm not sure on that as I think that license is not GPL compatible.

Basically, the GPL refers to "source code" which is vague when it comes to artworks. Nevertheless, being that the file is being redistributed in the same form in which it was received, then the GPL and it's "viral" clause absolutely does apply.

SFLC/FSF - One sentence summary: PHP in WordPress themes must be GPL, artwork and CSS may be but are not required.

So, it would appear that the SFLC/FSF came to the same conclusion that I did, using only common sense.

@chip_bennett | chipbennett.net (est. 2000) | WordPress user since May, 2005 | Linux (Kubuntu) user since September, 2007
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Bah. I disagree with their conclusion, as a theme is a single work, not a collection of works. CSS is useless without the accompanying HTML.

However, note that Matt basically says at the bottom that only 100% GPL themes will get promoted and/or hosted on wp.org.

On your last point: absolutely. For WordPress theme developers, the issue is almost entirely moot at this point.

And yes, inheritance of WordPress GPL to a WordPress theme as a whole absolutely depends on an interpretation that a theme is a single work, rather than a collection of works.

@chip_bennett | chipbennett.net (est. 2000) | WordPress user since May, 2005 | Linux (Kubuntu) user since September, 2007
cbnet Plugins