Interesting WordPress GPL implications

´GNU public licence´ forbudt?Recently I stumbled upon two posts that had pointed out interesting implications of WordPress using GPL as it's license. I guess not many gave a serious thought to that, me included. We all kind of know that GPL is something that is associated with 'free', we like that and use it as such.

But as attributing world of WordPress becomes more commercial every day, with paid plugins and 'premium' themes, I thought it is important to understand what GPL really brings to that world.

And the implication of GPL is this: all typical WordPress plugins and themes automatically fall under GPL license. In other words, even if you paid for that 'power' plugin or 'premium' theme, and even if author tried to put a different license on it, you are free to modify it, give it away for free or even resell it yourself.

The implication comes mainly from this paragraph of GPL:

You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License.

This means that whenever a theme or a plugin uses just one function from the WordPress code, GPL license automatically 'kicks in' and takes over. And since plugins and themes must use WordPress functions they automatically become GPL as well.

What this means..

You are free to remove those links from the theme that author tried to forbid you from (even from sponsored themes). Even when an author slaps a CC (Creative Commons) license on the theme, and demands you respect the links or work, you do not have to as they are actually violating the GPL by putting CC over it.

This goes for plugins as well. In fact for all WordPress based solutions. GPL allows you to do whatever you want with it including reselling it straight away.

Is there a solution?

The solution exists and is technical in nature. For plugins you can develop your whole code as a library under your own licensing model. Then you would have the wordpress plugin which will call functions from your library. The plugin itself becomes GPL but the library not and you are free to slap any kind of license and restriction to it.

For themes it is a bit of a different story. Having read the GPL FAQ carefully this is my interpretation. First solution: You do not need to call any WordPress functions in your theme, but you can connect to the database directly and get the information you need. This method is possible but not elegant at all.

Second solution is to have your theme in external php files and one WordPress index.php. This file will use WordPress functions and only include() your files as neccessary. Again index.php would fall under GPL, all other files won't.

Conclusion

Obviously core of the problem remains in choosing GPL as the licensing model for WordPress. There is a way out, not as elegant as we would like but possible nevertheless.

Also have in mind that GPL is not strict even in their FAQ. They often say "we think", "we beleive", "that's a borderline case" etc. which implies that the license is still a subject to free interepratation in many ways.


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42 Comments

  1. Sep 27th, 2011

    Very interesting license and thank you for bringing up the issue! Excellent point about GPL not being strict in their FAQ.

  2. Jun 9th, 2011

    I use WordPress for almost five years and must say I’ve not found a better platform for building and managing a website. Doesn’t matter whether you’re blogging, have a store front, create a massive business site or need a basic, static website to promote your services and products – WordPress can manage it all.
    And te themes are not only good for personal use, but also for your clients, makes it easier to customize to there style.

  3. Apr 21st, 2010

    "contains or is derived from" does not mean "links/binds with using API calls". The GPL discusses those issues seperately. "contains or is derived from" means "your new shipped product also happens to contain all or parts of this product", which is clearly not the case unless a theme is literally derived from a previous theme (i.e., it's a modification).

    Any further clarity required regarding this could (and should) be requested from the GNU License team (which I am not associated with).

  4. Dec 20th, 2008

    I do not think Matt needs to 'prove' it by doing what you suggest. GPL license is out there for everyone to read. We can differ on interpretation but the fundamentals are very clear.

    Here is a link to one more good read http://weblogtoolscollection.com/archives/2008/12/19/2hr-interview-with-matt-mullenweg/

  5. Dec 19th, 2008

    Again... not quite. It doesn't prove "it". It proves Matt's opinion, not quite the same thing :)

    Here is what I think Matt should do. Go and find another big company, say Template Monster, with lots of legal and monetary resources.

    Buy their top selling 20 WordPress themes, then put them up on WordPress themes as a free download.

    I am preety sure that TM will send him a C&D and then Matt and them can figure it all out in the courts.

    Then *finally* we can put this unresolved issue of GPL derivative works to rest and all move on :)

    Heck, I'll even have a whip round for Matt to buy the TM WP themes to start with ;)

  6. Dec 18th, 2008

    I am not giving legal advice only my opinion based on facts available to me, but you are right I should be more careful with that.

    Take a look at this post http://wordpress.org/support/topic/113358#post-543507

    Matt says there

    ... Themes link and use lots of internal WordPress functions, which make them linked under the GPL and subject to being a GPL-compatible license.

    From this, Matt's opinion is clear, themes are GPL and the recent removal of 200 themes from wordpress.org (another useful read http://www.alistercameron.com/2008/12/14/matt-mullenweg-wordpress-gpl/ ) only proves it.

    Here is a another quote from matt again, from just a few days ago:

    ... Themes whose sites said you couldn’t modify them (which is a violation of the GPL), ...

  7. Dec 18th, 2008

    "You are free to enforce GPL, you do not have to wait for Matt to do it. GPL gives you that right."

    Um, I don't really think so.

    1. That templates are GPL is not legal fact, tested in US court... its the opinion (based on his legal advice) of Matt.

    2. If an end user violated the GIVEN license of a theme, that theme vendor could sue..

    3. Thus, an end user would be violating a given license (e.g. CC) in the hope that a court case would get judged in Matt's favor... meanwhile, that end user would be burning through legal dollars.

    I think there are also legal implications for you to be dispensing legal advice... I think the popular phrase is....

    .....IANAL

  8. Dec 18th, 2008

    Mark (email?):

    The license says quite clearly:

    You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License.

    which to me means that if you just use the function, the code becomes GPL. As for the Apache argument, ASF and GPL are compatible so there is no argue there. Problem arrises when you try to use non-compatbile license like CC which brings me to Barrie.

    Barrie: You are free to enforce GPL, you do not have to wait for Matt to do it. GPL gives you that right. If you download GPL code you are free to modify it as you wish, distribute it further, resell etc.

  9. Dec 18th, 2008

    WARNING... INACCURATE LEGAL ADVICE WAS CONTAINED IN THIS POST

    "You are free to remove those links from the theme that author tried to forbid you from (even from sponsored themes). Even when an author slaps a CC (Creative Commons) license on the theme, and demands you respect the links or work, you do not have to as they are actually violating the GPL by putting CC over it."

    This is not true and I would advise against any of your blog readers to do this.

    If WordPress.org say the themes are GPL, then THEY (specifically Matt as I think he is the copyright holder) are the ones that must take the legal action.

    If the end user removes the links then THEY are the ones violating the copyright that theme was shipped with and could be liable.

    • Oct 1st, 2010

      Wow, This comment contains bad legal advice. Ha!

      I am not a lawyer, but when code is GPL, and it's distributed to you, you are given all the rights of the original author! You can change it, you can use it, you can even sell it to anyone you want for any price. You can also sue someone for violating your copyright. You must distribute the source and pass these rights on to anyone whom you distribute the code to.

      As for themes, HTML/CSS is not programming code. The design is not linked to the WordPress, unless MAYBE you used inline PHP in the HTML. However, the CSS file would still be separate. A theme framework for example is GPL code. The CSS file it uses is not.

      You could for example, acquire a GPL copy of Thesis from your friend, create an original CSS file for it and then sell thesis on your own website under a different name.

  10. Mark
    Dec 18th, 2008

    Vladimir: Otto is pretty much spot on.

    Your claim:

    This means that whenever a theme or a plugin uses just one function from the WordPress code, GPL license automatically 'kicks in' and takes over.

    ...is incorrect. If the author is making function calls to the core of WordPress, they can still license their code under a more restrictive license. It is only if they ship a, for lack of better words, modified duplicate of a function that's already in the WordPress core, which is when the GPL applies.

    Take, for example, the Apache webserver. It is licensed under the ASF, which is more restrictive than the GPL. However, Apache makes all kinds of Linux system function calls, and Linux itself is GPL. This isn't the exact same scenario as custom themes under WordPress, but it's pretty close. Were Apache to include custom code that was derived from Linux, it would have to be GPL, but it doesn't, so it doesn't. Same thing in this case.

  11. Amy Stephen
    Nov 17th, 2008

    Hi Lawrence - It sounds like you might be misunderstanding this discussion since your comments don't seem to be on topic. In short, my personal response was that one is not entitled to declare a plugin to be GPL if it has not been so licensed by the developer. I also think it's against the law to steal from cocaine dealers. Hope that helps!

  12. Nov 15th, 2008

    Let's bring this back to business principles and processes, something that a legitimate commercial business is held accountable to by a court of law (IRS, Better Business Bureau, UK Office of Fair Trade, ASIC, ATO, etc..)

    A commercial design studio creates creative works, as defined by the Copyright Act. These creative work may be integrated into applications such as WordPress, Joomla and the rest. Who therefore remains the owners of said copyrighted works ? Usually the design studio, unless they sign over the copyrights to their clientele.

    So by what right does Joomla (and/or WordPress) seek to create litigate against design studios around the world, in essence, making the work of those design studios GPL ?

    They have no right. The contracts employed by the design studios who utilise WordPress, Joomla and any other GPL based package do not utilise the GPL as a contract licence. At best, they are creating a service utilising GPL components to deliver a commercial solution for a business. The only laws pertaining to their work remain contract law (BBB / Fair Trading) and copyright. Not the GPL. The GPL is never invoked inside the contract, as the client usually requests a template for a particular CMS package. It does not matter if the CMS package is licenced under the GPL or not. The studio is contracted to deliver a creative work.

    This has been the fundamental achilles heel within the GPL debarcle that remains unspoken for a year. As long as the GPL is not invoked as part of the contract law between business and client, any licence can be applied. Creative Commons, Commercial copyright, whatever.

    Face it, Amy, every time you and the Joomla team you represent through the Communications team, seek to champion design contracts must be commercialised GPL, you profoundly misunderstand the nature of business contracts within the design world.

    Furthermore, thanks to the push towards "GPL compliance", Joomla, as a CMS, has attracted the cheap, hobby, unethical market where commercial components continue to be pirated or even worse, developers threatened with attempted hacks against them to pirate works. This is backed up by analysing Joomla.org over Quantcast and other measures.

    It's not the commercial developers fault that Joomla is attracting the bottom end (low/no cost) players who want to get into the web.

    It does seem ironic that the Joomla.org template design gets pirated so often that they've had to create a sticky and FAQ on it in the forum. And where do you think these pirates get the idea that it's okay to pirate from the Joomla.org site ? From the actions done by the SFLC, Joomla Core, and advocates such as Amy Stephen.

  13. Oct 30th, 2008

    Originally Posted By Otto>>The GPL only has any power over derivative code. If I write a separate piece of code that is clearly not derived from WordPress, then WordPress' license has no power over me at all, no matter what ZIP files I put it in.

    I agree, up to a point. If the original, non-derivative code is distributed within a package that is largely GPL I think you will find that the whole distribution is GPL.

    Themes/templates are more complicated. WordPress themes can consist of many different files and the hooks into the WordPress API are often a very minor part of the theme. If a theme can stand alone from WordPress (or any other web app) and look the same, regardless of whether the data is pulled in or not, then its arguable that the GPL applies. A theme developer could just as easily release a commercial theme with notes saying "add get_sidebar on line xyz between these tags".

    The issue of whether themes are GPL or not is not even clear on the GNU/GPL FAQ's http://www.gnu.org/licenses/gpl-faq.html#WMS

    There is a lot of misunderstanding over the GPL and a whole heap of arguments about its interpretation. But, at the end of the day, the only people who have any say in how their code is used are the copyright holders themselves. They are the only ones with rights to enforce the license and it would be very wrong of people to make assumptions about what they can or can't do with commercial themes or plugins. If they say their work is CC and you disagree, you should take this up with them but not breach their license. If its commercial GPL then there is nothing stopping you from distributing the work either free, or for a fee.

  14. Oct 24th, 2008

    >>Reading that paragraph from GPL again I get the impression that what Bad Behaviour does is not enough - you would need to also distribute GPL-ed and non GPL-ed files separately, because if you distribute is as one ‘work’ it automatically becomes GPL in whole.

    No. You can't automatically assume licensing just because somebody distributes stuff in the same ZIP file. The law is not that simplistic.

    If I write two pieces of code, then I own those pieces of code. If I then decide to license them differently, but put them in the same ZIP, nothing in the world can prevent me from doing that. I wrote the code, I own it, and I can do with it as I please.

    The GPL only has any power over derivative code. If I write a separate piece of code that is clearly not derived from WordPress, then WordPress' license has no power over me at all, no matter what ZIP files I put it in.

  15. Oct 10th, 2008

    @Ryan: Actually, OSX is based on BSD, which uses (obviously) the BSD license.

    This is why I keep recommending BSD-style licenses, because they are more permissive.

    As far as what your lawyer says, I'd be curious who that was, and what specifically they said. I'm not accusing anyone of anything, but developers tend to hear what they want to hear in regards to things said about licensing.

    The lawyer may have said that it's ok to produce commercial software that contains GPL-licensed source. That is true. That doesn't preclude it from itself being GPL-licensed and being subject to the terms of the license. Remember, GPL does not mean non-commercial.

  16. Oct 10th, 2008

    I'm not a lawyer so am not going to attempt to explain the details, but I recently had a long discussion with a lawyer who specialises in copyright law about this topic. I was told there is no issue with integrating GPL code into a commercial product.

    Apple's Mac OSX is a prime example of this, it apparently contains a lot of code acquired from Linux (GNU/GPL), but as a whole it is considered an original piece of work, hence anyone who is caught providing a copy of OSX for download will quite rightly land themselves in hot water with the Apple legal team.

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