WordPress Creator GPL Says WP Template Must Be GPL'd

An anonymous reader writes "Matt Mullenweg (the creator of open source blog software WordPress), after review by various legal experts, is sticking to his guns that themes and plugins that 'extend' WordPress violate the GPL if they are not themselves distributed under the GPL. Matt has gone so far as to post this on Twitter. According to Matt, the premium template called Thesis should be under the GPL and the owner is not happy about it. WordPress is willing to sue the maker of Thesis theme for not following GPL licensing. The webmasters and Thesis owners are also confused with new development. Mark Jaquith wrote an excellent technical analysis of why WordPress themes inherit the GPL. This is why even if Thesis hadn't copy-and-pasted large swathes of code from WordPress (and GPL plugins) its PHP would still need to be under the GPL."

Comments

And this folks...

[DarkKnightRadick]

...is why I don't do any work creating anything for WordPress. CopyFree is the way to go.

Re:And this folks...

[cgenman]

...is why lots of businesses won't touch open source software. It is stuff like this that gives ammunition to the FUD.

Re:And this folks...

[MightyMartian]

What FUD? GPL is pretty clear. The developer in this case was an idiot. If you don't want to be bound by any particular license's restrictions, open source or otherwise, don't use stuff licensed using it, or at the very least don't release it publicly.

Re:And this folks...

[LordPhantom]

...except not all open source software is licensed with the GPL. If anything the issue is less with OSS as a concept and more with the licensing wordpress uses.

Re:And this folks...

[TheKidWho]

Translation: Profit is evil.

Re:And this folks...

[ehrichweiss]

Even better, why don't Thesis just make a "templating engine" to handle the WP code that can then be released under GPL and then release the rest of the CSS, images, etc. under their own license? I can think of a couple of ways this could be accomplished and it would protect Thesis entirely.

From the WP "analysis" on one of the links in the summary...

****
"My JS/CSS/Images are 100% original. Do they have to be GPL?

No, they don't. If they aren't based on GPL'd JavaScript, CSS, or images, you are not forced to make them GPL. What you could do is offer a theme under a split license. The PHP would be under the GPL, but other static resources could be under some other license."
****

That said, I'm a bit concerned about how this "it's a part of WP" will be interpreted because doesn't that then mean that commercial apps like Zend Studio, etc. are ALSO required to comply with the GPL since they ostensibly hook into the various GPL'ed libraries, etc. ??

I mean I'm all for GPL but if everything that so much as touches GPL'ed software falls under that license, we're going to find fewer and fewer people willing to create commercial apps for GPL OS'es, etc..and while I may not use it, we definitely don't need to go shooting ourselves in the foot at this stage of the game.

Re:And this folks...

[ircmaxell]

The GPL is as clear as mud. Do you want an example? It says "derivative works" must be GPL as well. Well, what is a derivative work? Guess what? The GPL itself doesn't define that term. So there's huge debate as to if a block of code that uses nothing from the parent but fully documented and exposed APIs is derivative or not.

Obviously Ubuntu is a derivative of Debian; that much is clear... But is Internet Explorer a drivative of Windows (Taking aside the license for a minute)? It hooks into deep APIs (So deep in fact, that it cannot run on any other OS than Windows)... Parts of the core of Windows (Windows Update) depend upon it... It's a very difficult question to answer.

And this is why I hate the GPL. It promotes the "If you want to comply, you can do no wrong by licensing GPL" attitude. It's trivially easy to comply with, but it's VERY hard to make a clear determination if the restrictions extend to you or not. So most people "just take the easy way out" and license GPL. Not out of belief, not out of fear, not out of requirement, but out of confusion and misunderstanding...

Re:And this folks...

[shutdown -p now]

What FUD? GPL is pretty clear.

How (and even if) GPL applies to dynamic linking - which, in this case, what it really boils down to - is very far from clear. This is especially true for languages where the actual "linking" happens on user side, not on developer side - i.e. anything using a bytecode VM (JIT or no JIT) or a plain interpreter. Such as, well, PHP.

Yes, the FSF has a well-defined and widely publicized position on this issue, but that is separate from the text of the license as such, and it is not certain if the text really means what they want it to mean.

The correspondence of Stallman with the author of CLisp - where the former argues that mere use of GNU Readline APIs (i.e. invoking a function named "readline" with arguments of specific types) in your code makes it a derived work under the GPL - is a very interesting read in this context.

Stallman's argument hinges on the claim that the mere existence of Readline means that any program using its APIs is derived work. If you buy into that line of reasoning, then just imagine what the implications would be for any FOSS having to do with clean-slate implementation of proprietary APIs (consider the SCO-IBM case and Wine for a few specific examples; there are many more). I also very much doubt that the court would buy that; indeed, by the end of the email exchange, Stallman also seems to be implicitly acknowledging that, changing his argument to "if you manage to circumvent GPL this way the Evil Proprietarians out there will know they can use it too, and it's BAD BAD BAD, so please do as I say".

This case seems to be similar. The claim is that the template is GPL'd because it contains calls to functions with names and arguments such that they match the WordPress internal APIs. However, one could do a clean-slate implementation of all those APIs (it wouldn't even have to do anything useful; think mocks), and the template script will happily run on top of that as well. And it doesn't contain any actual WordPress code. So, if it doesn't actually require WordPress to run, why should it be considered a "derived work"?

Re:And this folks...

[DragonWriter]

What FUD? GPL is pretty clear.

In this particular case (as apparently there is large cut and paste of code), this seems to be a pretty clear issue; OTOH, the more expansive interpretations often offered of the GPL (including the interpretation that would hold that all templates, etc., for a GPL blogging platform needing to be GPL) is arguably untenable, as many of the things which proponents of this view would demand that the GPL must apply to are not what would otherwise be considered derivative works, and consequently require no license to produce in the first place.

Re:And this folks...

[Sloppy]

If that's why, then they're idiots. The WordPress guys are not talking about their license or even WordPress itself; they are issuing an opinion about what Congress and the court's inconveniently undefined implied definition of derived work is. Their opinion would apply just as well to proprietary software as it does to Free software. If you write a Microsoft Windows program that calls Windows and is also called by Windows in the same way that Windows calls itself, like say, an installable filesystem or a device driver or perhaps even an MSIE plugin, then these guys would say that your program is a derived work of Microsoft's product. This flavor of FUD, much like software patents, is a threat to all software, not just Free software.

BTW, if you really want to fuck around with people who have this perverse view of what a derived work is, write a new system that is compatible with WordPress plugins. Then all WP plugins will automagically and retroactively become derived works of your program in addition to WordPress itself. License your program in a way that is incompatible with GPL and then you'll end up with a beautiful paradox. Their heads will explode, we can hose the mess away, and all will be well again.

Re:And this folks...

[Sloppy]

GPL is pretty clear.

GPL is irrelevant. A license does not have the capacity to define what a derived work is. You've got your dependency hierarchy backwards.

Now, I'm not saying FSF's (the GPL's author) legal opinions are irrelevant and can lightly be blown off, however wrong they happen to be. ;-) And I applaud their efforts to try to change public opinion by attempting to write a license that redefines the law which causes people to become bound by that license. Bootstrapping attempts can be wonderful works of art. But it's an illusion.

Re:And this folks...

[Peach Rings]

How is dropping a text file in the same folder as wordpress creating something that is "part of WP"? This is exactly the kind of restrictive insanity that free software licenses were supposed to eliminate.

Re:And this folks...

[grumbel]

In piracy articles, other people's work is free to trade. In GPL articles, other people's work suddenly should be protected.

There is no conflict, both are done to maximize the users freedom.

In reality, without copyright, the GPL would have no power, because it's a copyright license!

And that would be quite fine, as it would allows the reuse and recycling of other peoples work. It would however get a little messy, as reverse engineering and decompilation might often be needed. In practice however most people don't argue the abandonment of all copyright anyway, just a drastic shortening of it and extended fair use.

Re:And this folks...

[amorsen]

Then all WP plugins will automagically and retroactively become derived works of your program in addition to WordPress itself.

That isn't how copyright law works. Copyright cares about the history of how the particular bits came into existence.

Re:And this folks...

[dgatwood]

Under GPLv2, you would have been correct, as the term "distribute" has specific meaning in copyright law, a definition that would generally exclude moving copies of copyrighted material around within a company (so long as you do not give it to contractors or other companies working with you, IIRC, but my memory of those aspects of copyright law are kind of vague, so take that with a grain of salt).

The problem is that the term "distribution" isn't the term used by the GPLv3. The GPLv3 uses the term "propagate", and defines it as follows:

To "propagate" a work means to do anything with it that, without permission, would make you directly or secondarily liable for infringement under applicable copyright law, except executing it on a computer or modifying a private copy. Propagation includes copying, distribution (with or without modification), making available to the public, and in some countries other activities as well.

Clearly, putting it on multiple computers does constitute propagating, but as it is done by the IT person, only that IT person would retain the right to distribute further copies. Offering it for internal download, again, clearly qualifies. Why? Because without permission to copy something, making additional copies for additional machines would be a copyright violation.

The GPL is actually remarkably clear on this point; making something available to the general public is not required for the license to kick in, and internal distribution does count. The concern over internal distribution is legitimate, at least under GPLv3. Don't like that? Pick software with a better license next time, like GPL version 2.

Re:And this folks...

[DragonWriter]

In other words, it depends a lot whether the non-GPL theme developers ever distributed Wordpress to anyone. If they didn't, they can argue that their themes are not derivatives according to copyright law, and they may have a chance. If they did, they have accepted the GPL's interpretation, and that will be difficult to get around in court.

Well, except that most of the "definition" of "derivative works" that is contentious isn't in the GPL, but in a section qualified with "we believe" in the FSF's FAQ concerning the GPL, so it isn't part of what people "accept" when they accept the GPL.

Re:And this folks...

[locallyunscene]

Can you suggest a Google search for such cases because I haven't heard of them. Well, I had thought this was THE case, but after reading more about it I think WP is right and people claiming that GPL APIs are somehow tainted are misinformed. I would read WP's argument above. At first I was skeptical, but he makes a pretty clear distinction between a derivative work and an external work that uses APIs.

On APIs

WordPress has many external APIs that spit out data. Interacting with these APIs does not put your code on the same level as core WordPress code. These APIs include Atom, RSS, AtomPub, and XML-RPC. Something that interacts with these APIs sits entirely outside of WordPress. Google Reader doesn’t become part of WordPress by accessing your feed, and MarsEdit doesn’t become part of WordPress when you use it to publish a post on your WordPress blog. These are separate applications, running separately, on separate codebases. All they are doing is communicating. Applications that interact with WordPress this way are separate works, and the author can license them in any way they have authority to do so.

This is a wholly different model of interaction than with themes. Themes are not standalone applications. They are scripts that become part of WordPress itself, and interact with WordPress on the same level that WordPress interacts with itself.

For the sake of argument let's pretend WP was a commercial product. Do you think you'd be able to create a theme for it and release it and sell it and not have it be considered a derivative work?

Re:And this folks...

[B'Trey]

How is dropping a text file in the same folder as wordpress creating something that is "part of WP"?

It doesn't. I can take a copy of this post and drop it in a WP folder and it's not affected in any way.

What causes it to be "part of WP" is the fact that the contents of the file in question literally become part of WP. From the last linked article:

There is a tendency to think that there are two things: WordPress, and the active theme. But they do not run separately. They run as one cohesive unit. They don't even run in a sequential order. WordPress starts up, WordPress tells the theme to run its functions and register its hooks and filters, then WordPress runs some queries, then WordPress calls the appropriate theme PHP file, and then the theme hooks into the queried WordPress data and uses WordPress functions to display it, and then WordPress shuts down and finishes the request. On that simple view, it looks like a multi-layered sandwich. But the integration is even more amalgamated than the sandwich analogy suggests.

Here is one important takeaway: themes interact with WordPress (and WordPress with themes) the exact same way that WordPress interacts with itself. Give that a second read, and then we'll digest.

Re:And this folks...

[tomhudson]

PHP is an interpreted language - "dropping a text file in the same folder" is actually adding code - creating a derivative work.

Absolutely not - otherwise, dropping a css file into a folder would also be creating a derivative work.

One of the problems is that the developers are taking the position that "because they don't work in separate processes, they're one program." This is absolutely false. Back in the single-process DOS (and pre-DOS) days, all programs "worked in the same process space", yet they were still copyrighted. Clearest case in point is a TSR (Terminate and Stay Resident - for you young'uns).

The argument that calling the APIs is not sufficient isolation is totally bogus. Calling an API does not make your code part of that code, any more than calling, say, the Windows API means that your program suddenly is merged with Windows and licensed by Microsoft.

When the guy argues in response to this question

So the Plugins API is actually not an API?
Why is it called Plugins API then?

Strictly speaking, no, it isn't an API. It's how WordPress itself is written! "X API" in this sense loosely means "WordPress core functions for purpose X."

It is not "an interface implemented by a software program which enables it to interact with other software." It's just functions. The use of API in this case is technically incorrect, but it's become common parlance, at least in the WordPress community. The incorrect label doesn't change my view of how plugins, themes and WordPress core form a single application, as explained above.

I'll give those links a read.

That's just idiotic. Even a c API is "just functions".

This whole thing is dumb.

Is the php code linked in, in any way, even at runtime? No. They both get run by a separate process, the php interpreter.

I'm in favour of the GPL, but this is beyond stupid.

Re:And this folks...

[yakovlev]

This is why (particularly for things like interpreted languages, but even for things like the Linux kernel) the correct thing to do is to label various interfaces as internal or external. Internal interfaces are those that, if called, make your work a derivative work. External interfaces are those that are considered "using" your work, and thus do not create a derivative work.

As a rule, internal interfaces are specific to HOW your implementation works, whereas external interfaces are more general to WHAT your software does. As such, internal interfaces are more subject to change. There are of course exceptions.

This kind of distinction is particularly important for applications that offer a plug-in or theming API.

Some cases are cut-and-dry:
If you modify GPL source code, your modification becomes GPL.
Most GPL libraries are pretty explicit that EVERYTHING is an internal interface and referencing it make a derivative work. Data is the only thing that doesn't.
For LGPL libraries, linking and calling pretty much any function exported by the original work fails to create a LGPL derivative work.

Other cases are tougher:
A plug-in may operate in the same process space as the main application, but may be considered a separate work if it only calls documented plug-in APIs.
Certain Linux kernel drivers are considered okay (graphics drivers) but others are considered too tightly tied to the original work.

Consider this: If a minor modification to the function call implementation (think remote function call) causes the answer on whether or not it's a derivative work to change, then the line wasn't clearly drawn.

This smells like one of those cases. If PHP scripts were called in a different process space, that would seem to change the result of the analysis, which means we're definitely in dangerous territory.

Without really understanding all the details, it sounds like the developers have made what was generally treated as a public API into an internal one. If it was clearly (READ: In the API documentation) stated as being an internal API that creates a derivative work, then you're okay. If, after the fact, you're saying "no, that API that we treated as public/external really wasn't" then you're in hot water. If this goes to court, you better believe that the documentation and the early mailing list/forum posts by the primary developers will be presented as evidence. If it looks like they EVER implied that you were free to use those without creating a derivative work, then the argument for NOT derivative has a pretty strong case.

NOTE: As was conceded in the comments of the analysis, simply running in the same PHP process without calling WordPress (WP) code isn't enough to create a derivative work. Also conceded in the main article was that using the WP RSS APIs (presumably outside PHP) also do not create a derivative work. In that sense, it seems pretty clear that he considers the RSS APIs to be external while the theming APIs are internal.

The question becomes: Was this ALWAYS clear? If not, you can't go changing the rules just because you don't like what somebody is doing with your work. If it was just ambiguous, then it's a toss up as to who wins. If you were lenient earlier and are now trying to tighten your grip saying that they were wrong all along then you are likely to lose, at least with a jury.

Consider, for comparison, a GPL C library, where there's pretty good agreement on what the rules are. The C library is released as an incomplete "part of a program" where a program that derives from that part must become GPL. It's generally fair game to make that a simple but useful program (think cat/grep) and release to code for that. Then that GPL program can be called by a more complicated program that then does not become GPL. It gets ambiguous but generally not allowed when you make a program that basically exposes the internal APIs without doing anything useful beyond exposing those APIs, and then write a separate non-G

Re:And this folks...

[tomhudson]

Interpreting scripts has nothing to do with linking. This is a major fail in understanding by the original author, and it's obvious from reading the debate that, like most web monkeys, he's not had extensive experience with real programming languages, where you have a compile and LINK.

Scripts do not "link" to each other at any time. To link has a very specific meaning. It binds a jump instruction to an address. Interpreters don't do that, because the php scripts are not object code.

In fact, if you have two php scripts that are mutually dependent, neither one actually calls the other - the interpreter is sitting there in the middle. IT doesn't call either script, since there's no object code to "call". Instead, it reads the script, interprets it, and runs it's own internal code based on the parameters in the script. For example, when it sees a printf() command it doesn't run the printf code in the script - there is none. Instead, it reads the parameters, then run's it's own internal copy of printf.

Same thing with include(). The main file never actually "includes" the other file - instead, the interpreter sees the request, looks for the parameter, then executes a whole sequence of events - loading the file and interpreting it.. At no point does the first file now "include" any code from the second file. It is totally unchanged, both on disk and, more importantly, in memory.

Simply put, scripts that interact via an interpreter with other scripts can have their own separate license. There is no "viralness" in an interpreted world, since there is no linking, and no "incorporating" one script into another unless they are physically appended on the disk before being loaded into the interpreter. You can distribute a php script you wrote that interacts with a GPL script, and you're free to attach any conditions you want to your script - or none.

Re:And this folks...

[the_womble]

How is dropping a text file in the same folder as wordpress creating something that is "part of WP"?

The "text file" contains PHP, including modified versions of code copied from Wordpress itself.

Re:And this folks...

[butlerm]

On the other hand, you can hardly argue that your module would be of much use to anyone without a Linux kernel to run it in, and you must have referenced the kernel source, or documentation derived from it, during the implementation, since the APIs don't exist anywhere else.

A derivative work must be _substantially similar_ to a pre-existing work to be considered derivative. Interface compatibility, no matter how obscure the interface, no matter how much access, no matter how much documentation, does not in and of itself make your work substantially similar to another work.

If you were making a clone of an existing module, or an entire application, source code access and substantial internal similarity would be prima facie evidence that you have created a derivative work. Interface compatibility without substantial internal similarity isn't even _relevant_.

17 USC 102(b) seems relevant here: "In no case does copyright protection for an original work of authorship extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained, illustrated, or embodied in such work."

Re:And this folks...

[Compaqt]

Matt M. claims that large portions of the Thesis theme includes cut-and-pastes of PHP code from WordPress GPL code.

I don't know exactly how much that is, but it's probably more than none whatsoever.

(Take it for what it's worth.)

Implications for plugins

[popo]

Given that loads of major software companies have released plugins for WordPress, including payment gateways, social networking plugins, twitter plugins, etc ... doesn't this expose a huge amount of proprietary code to potential (and possibly unintended) open-sourcing?

Re:Implications for plugins

[Hatta]

No. It exposes a huge amount of authors of proprietary code to a copyright infringement lawsuit. How they settle this is up to them, but they can't be forced to open their code. In any case, they'll get off a lot easier than if they had misappropriated proprietary code.

Re:Implications for plugins

[Annirak]

It really doesn't, actually. The only time that a company would have a problem with this is when they distribute their plugin or theme. Any company which makes a WP template or theme is absolutely not required to open source it unless they distribute it. This means, obviously, that the majority of company-specific plugins and themes are not going to need to be opensourced.

The only companies which stand to be hurt by this are the ones which have a business model of making wordpress plugins/themes and selling them. Even then, they are not required to stop doing so. The requirement is just to license their software under the GPL and provide source if and only if someone requests it.

People act like the GPL will kill all software business as we know it, but those who do so clearly haven't even read the license.

Re:Implications for plugins

[0racle]

What part about it makes him a troll or a moron?

The "It's infectious" part makes him a troll or a moron.

Re:Implications for plugins

[Anonymous Coward]

The "It's infectious" part makes him a troll or a moron.

In other words, a person who is telling the truth is a "troll or a moron"? You couldn't seriously believe that.

Details, details

[MaggieL]

"People Who Care About Details Trust Thesis". -- http://diythemes.com/

Presumably the licencing of the platform you're developing for could be considered a "detail"

data vs code

[roguegramma]

Just goes to show that data vs code is a false dichotomy:
The programming language and data description language used should not affect where the split is.

This is even more obviously worse if you for example transfer your data as JSON, so that the data interchange language is the same as the programming language.

I don't buy it.

[PylonHead]

IANAL, but I don't buy it.

The GPL is based on copyright.

If I sell a product that doesn't contain *any* of your copyrighted code (and API calls certainly can't be copyrighted), you have no basis to sue me for copyright.

Re:I don't buy it.

[orkysoft]

FTFS:

This is why even if Thesis hadn't copy-and-pasted large swathes of code from WordPress (and GPL plugins) its PHP would still need to be under the GPL.

Re:I don't buy it.

[daid303]

GPL is much wider then just the code. GPL states that anything linked to it needs to be GPL. But in the case of PHP this is a bit fuzzy, when is it linked or not?

GPL is made for C programs running on something you own. The cases of interpreted code, and code running on a webserver hosting services are not covered in it. So I can customize wordpress, run it on my own server, and nobody has any right to get the source then. Except for myself.

Re:I don't buy it.

[improfane]

This is like the GPL libraries. If your project uses a GPL product, does it become GPLed too (and you want distribute it)? Yes, it does. Why you should not use the LGPL for your library.

Essentially, you're using Wordpress as a library, which is GPL and not LGPL. It makes sense, it's just your (and my) perceptions of what constitute as data and code is blurred with templates. You'd think they'd be a data structure but they're actually code. It's the same in Joomla too: most templates I have read have to copy and paste lots of code from the default templates to get the same basic behaviour.

So they use Wordpress as a library and they then "become" GPL or they're violating.

Re:I don't buy it.

[guruevi]

Yes you can, the GPL only talks about distribution. The thing is the moron copied and pasted WP source code and then went ahead and charged for it. Besides that, PHP include and require makes the files part of it's own program and then compiles it - it becomes a single program. If you don't like that, use exec or system. It would be the same as releasing a GPL program written in C++ but then not releasing the header files under the GPL.

Twitter

[sbates]

Matt has gone so far as to post this on Twitter

Offenders are really gonna get it now. This guy means business.

It comes form scope creep

[Sycraft-fu]

The idea of the GPL, at least the original idea, seemed to be that if you modified the code of a project and distributed that modified version, you also had to distribute the code. Ok, fair enough and easy enough to understand. So Linksys could go and use Linux on their routers, and they have to release the mods to Linux they make, but not any of the software they run on it.

However then you get things like this. A theme for something they now say has to be GPL. Not a new version of the software, a theme that adds in to it. Ummm ok. What about plugins, do those also have to be opened up? This leads to other worries, will GPL authors try and say if you use a GPL'd software to create something (like a picture with GIMP) that too has to be opened up?

That is some of the "viral" nature MS was bitching about. You GPL something and then you want to say everything it touches has to be GPL'd too.

I think people get a little miffed when they find that using GPL software got them more than they bargained for.

Re:It comes form scope creep

[MightyMartian]

The issue here is the way that PHP and Javascript, in particular, are being used by these open source projects. Where the dividing line between data and code is unclear, or possibly doesn't meaningfully exist at all (JSON for instance), it doesn't take a rocket scientist to figure out that themes that are as much code as they are presentation are probably going to end up being swallowed into GPL.

The solution is simple. Find a platform that isn't GPL, or write your own.

Re:It comes form scope creep

[improfane]

In Wordpress the templates are PHP calls to functions, so it is basically a contribution to the codebase in itself. It's not a templating language what you would expect.

Not that I understand GPL or Wordpress but that sounds like the logic.

I honestly don't see how CSS could become GPLed though.

Re:It comes form scope creep

[NNKK]

you could say the same thing about software that calls functions in a GPL library, does software that dynamically links against a GPL library have to be GPL? Its calling functions in defined in GPL code.

Yes. Please read up on dynamic linking and the GPL and LGPL. The questions your asking have been asked, answered, and discussed by many people every day for the past twenty years. Try Google, it's very useful.

He has no case

[MikeRT]

If he's taken GPL code and put it in Thesis, game over. It's GPL. Period. Whatever he could have argued about API calls is now irrelevant.

At this point, the only thing I'm curious about is what would happen to WordPress users who start to distribute Thesis without his permission.

Re:He has no case

[shutdown -p now]

I apologize for posting incorrect information. Thesis does contain portions of GPL'd code directly copied from WordPress. So what you say is 100% true, regardless of the take on GPL vs dynamic linking and APIs. I somehow managed to read TFA without noticing that bit :( Also see this.

However, I still stand by my assertion that any other WordPress theme which did not directly copy WordPress code cannot be reasonably considered a derived work for copyright purposes (and therefore not subject to the GPL), contrary to what WordPress authors claim.

It's a pity that this case is a GPL violation so blatant that it will never get to the point of debating those (far more interesting) issues in court - in fact, I doubt there will even be a court.

If themes are derivatives, then all C programs are

[jabberw0k]

Themes contain code that works to a certain API. If a theme contains no lines of Wordpress code, then by definition it could work with any program that used the same theme API.

How then can Wordpress say that its licensing is required?

Thanks for the traffic. I'll get my site back up.

[AndrewWarner]

I run Mixergy.com, where I did the interview with Matt & Chris. Sorry my site is down. I'm working on it now.

So ... WordPress should use the PHP License?

[wesw02]

His argument is that WordPress Plugin should be bound to the WordPress license because it uses hooks and attributes from their API. By that very argument Wordpress should be using the PHP License.

Re:GPL people make it clear in their FAQ

[chipbennett]

The GPL doesn't define "derivative work", nor does the FSF's GPL FAQ; only the Copyright Act does. If the GPL's interpretation of "derivative work" differs from that of the language of the Copyright Act, or of applicable case law, then the GPL's interpretation will not withstand a court challenge. And in fact, the interpretation of FSF/SFLC/Matt Mullenweg/et al that WordPress Themes are inherently derivative of WordPress core, and therefore inherit GPL, runs exactly opposite to relevant copyright case law.

Check out the case law.

[Anonymous Coward]

Themes don't inherit the GPL. See the following article:

WordPress Themes, GPL, and Copyright Case Law
http://www.chipbennett.net/2010/07/wordpress-themes-gpl-and-copyright-case-law/

Re:Can someone clear up a misconception of mine?

[PhrstBrn]

You're confusing LGPL and the GPL. The LGPL has a linking exception, the GPL does not. You cannot distribute code linking to GPL code without using a GPL compatible license. If you link to code distributed under the LGPL, you're fine. The only thing you need to distribute is the the actual library you linked to, if you made any changes, but not the rest of your codebase.

Wordpress is GPL, so linking to any of the Wordpress codebase requires distributing your code under the terms of the GPL. I don't see how you can make a useful Wordpress theme/template without making a Wordpress call somewhere. Printing out a post, or comment is going to require a function call to some GPLed code.

I believe the creator is correct, as long as Wordpress remains pure GPL, most non-GPL themes and plugins are going to break the license. It is entirely possible to create a non-GPL plugin, as long as you don't need to make any calls to Wordpress functions or internals.

Interpreted vs compiled, there is no difference in the interpretation of the license. Linking in an interpreted language is treated the same as linking in a compiled language.

Re:If themes are derivatives, then all C programs

[shutdown -p now]

It's worse than that. If you RTFA, they make the claim that there are "external APIs" and "internal APIs", and using the former is perfectly fine and dandy, while using the latter makes your code a derived work. Since the classification is, effectively, arbitrary and subject to change at the whim of the author, this puts any software relying on any WordPress API at risk.

That ain't the GPL's responsibility.

[Chris Burke]

Well, what is a derivative work? Guess what? The GPL itself doesn't define that term.

Of course it doesn't, since that term is defined by the legal code regarding copyright in your jurisdiction. Because the GPL is not anything else but a copyright license, it cannot apply to anything which is not a derivative work by the definition of the relevant legal code, because anything not a derivative work is not restricted by copyright law. So if the GPL did give a definition it would be irrelevant, and if it happened to differ from the legal definition at your current location in space-time, it would be wrong. How's an irrelevant and wrong definition going to reduce confusion, exactly?

But then you go and look at the legal code and see that, what do you know, the real definition of derivative work is vague. This is an issue that applies to all of copyright, and sparks many debates (and lawsuits), and has nothing specifically to do with the GPL. The lack of a clear definition is not something the GPL can fix.

It's trivially easy to comply with, but it's VERY hard to make a clear determination if the restrictions extend to you or not. So most people "just take the easy way out" and license GPL.

It's a fair point, that people license their own code GPL just because it's the only way to be sure they aren't violating the GPL of some other code they are using.

However the same issue of confusion applies in any situation where it matters whether you're creating a derivative work or not. With proprietary software, that means people "take the easy way out" and avoid doing anything with the software that could possibly be derivative. The only time the issue doesn't matter is when the license is so liberal it doesn't matter if your work is derivative or not because you can just repackage it with whatever license you want anyway.

And while BSD-style licenses are great for those who want to give away code, I don't think it's worth abandoning the advantages of Copyleft just to avoid the stick issue of what exactly constitutes a derivative work.

Copyright law defines a derived work.

[Anonymous Coward]

Copyright law defines a derived work. Why does the GPL have to?

"And this is why I hate the GPL."

And this is why you want the GPL to do so. So you can disobey copyright law.

"It promotes the "If you want to comply, you can do no wrong by licensing GPL" attitude."

And this is wrong how?

"but it's VERY hard to make a clear determination if the restrictions extend to you or not."

Blame copyright law then when it comes to software and what defines a derived work under copyright. That's defined by law (as is what determines a copyrightable product).

"So most people "just take the easy way out" and license GPL. Not out of belief, not out of fear, not out of requirement, but out of confusion and misunderstanding..."

Most people use MS Windows because it's the "easy way out". Not out of belief, not out of utility, not out of requirement, but out of confusion and misunderstanding...

I don't hear complaining from you there.

How WordPress Works, and Why the Authors are Right

[salesgeek]

WordPress themes are simply PHP libraries that WordPress calls when rendering a page. The license status of Wordpress themes are very much dealt with in finality by the GPL, and there is absolutely no question that the PHP files must be licensed per the GPL.

From the GPL's narrative:

This General Public License does not permit incorporating your program into
proprietary programs. If your program is a subroutine library, you may
consider it more useful to permit linking proprietary applications with the
library. If this is what you want to do, use the GNU Lesser General
Public License instead of this License.

Does WP call the theme or does the theme call WP?

[Fencepost]

In this particular case it sounds like Thesis is screwed because they're incorporating WordPress code into their theme - game over.

In the more general case, I think you could make a credible argument that WordPress is designed to look for and utilize external libraries (called "themes") and that just doing so should not make WordPress' license apply to that theme (or plugin). My reasoning there is that if you argue that WordPress incorporating a theme makes the WP license (GPL) apply to that theme, what prevents that theme's license from correspondingly "infecting" WordPress?

Jaquith misses the point

[harlows_monkeys]

His analysis is all about how the code works when someone takes a theme and loads it in WordPress. While accurate on the technical details, it completely misses the point. When someone runs a theme in WordPress, they have caused a derivative work of WordPress to be created. They've also caused a derivative work of the theme to be created. No one seriously questions this. However, the license of WordPress allows this, so there's no problem here.

The important question is whether or not a WordPress theme, AS DISTRIBUTED BY ITS AUTHOR, is a derivative work, and he fails to address this. The answer to that depends on whether or not the theme has incorporated (by copying, transforming, adapting, etc) any copyrightable elements of WordPress.

The particular theme in question did include such elements, and so has a problem. However, in general, you do not appear to have to include any copyrightable Wordpress elements in a theme, and so a theme does not inherently have to be GPL.

The majority of court cases that are relevant to this agree that writing code X to interface to code Y does NOT automatically make X a derivative work of Y. The FSF thinks that merely designing code to link with another piece of code makes the first a derivative work of the other, but there's no court cases that support that view, and better lawyers (such as Larry Rosen) than the FSF uses say that it doesn't automatically make a derivative work.

Re:Marketing

[silentcoder]

>I like open source but the GPL is sounding more and more dangerous.
when even it's advocates can't seem to agree on what exactly it covers I'd be worried.

That's just not true. It's advocates are all in unison here that it covers works like this. It's on idiot in Florida who dissagrees and he is hardly an "advocate".