WordPress Themes, GPL, and Copyright Case Law

Filed in Web DevelopmentTags: Copyright, GPL, Judiciary, Plugins, Themes, WordPress

Within the WordPress community, the question of GPL inheritance of WordPress themes erupts into contentious debate with the reliability - if not the frequency - of Old Faithful. While I understand that, according to the GPL interpretation of Matt Mullenweg, the Free Software Foundation (FSF), and the Software Freedom Law Center (SFLC), WordPress themes are derivative of WordPress and therefore must necessarily inherit WordPress' GPL, I would like to investigate the issue not in light of their interpretation but rather in light of copyright law and precedent case law.

Before I begin, let me add an important caveat: I have no qualms with the GPL. I have always released - and will continue to release - under GPL anything I develop related to WordPress. I do so because I choose to do so, as a means of making even a minor contribution to a project from which I believe I have personally benefited. I do have issues with how the GPL-inheritance question has been handled - but those issues are out-of-scope for this post.

Having (hopefully) made that point clear, let's begin!

What US Copyright Law Says

US Copyright law defines a "derivative work" as such:

A “derivative work” is a work based upon one or more preexisting works, such as a translation, musical arrangement, dramatization, fictionalization, motion picture version, sound recording, art reproduction, abridgment, condensation, or any other form in which a work may be recast, transformed, or adapted. A work consisting of editorial revisions, annotations, elaborations, or other modifications, which, as a whole, represent an original work of authorship, is a “derivative work”.

Note the key adjectives: recast, transformed, and adapted.

Consider also Section 102(b), which states:

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.

This clause establishes the boundary around copyright between copyrightable expression, and non-copyrightable ideas.

Summarizing GPL Inheritance Requirements

To summarize GPL requirements regarding license inheritance for derivative works 1:

  1. The GPL only applies to distribution of a (modified or unmodified) GPL-licensed work, or a derivative work. Any activity involving use, modification, or creation of derivative works that does not involve distribution is outside of the scope of the GPL.
  2. Distribution of a (modified or unmodified) GPL-licensed work, or a derivative work, requires that such distribution be licensed under GPL.

The GPL is what is now referred to as a "copyleft" license: a modified public-domain license that takes advantage of the exclusive rights granted by copyright law to prevent derivative works from being restrictively licensed. Since the copyright owner has exclusive right to produce and to distribute derivative works based on the copyrighted work, the GPL intends to grant unlimited usage rights (to use, study, modify, etc.) to the end-user, while forcing follow-on developers of derivative works to release those works under the same license.

It is important to understand that, because the GPL explicitly defines any activity not involving distribution to be out of the scope of the license, and since right of distribution is solely derived from copyright law, that GPL derives its legal basis from copyright law alone. This distinction separates the GPL from most other traditional software licenses, which derive their basis for usage and modification restrictions not from copyright law, but from contract law.

Notes:

  1. WordPress is released under GPL version 2.0. I'll try to summarize below the parts of the license germane to derivative works.

    First, from the Preamble:

    The reason we have a separate public license for some libraries is that they blur the distinction we usually make between modifying or adding to a program and simply using it. Linking a program with a library, without changing the library, is in some sense simply using the library, and is analogous to running a utility program or application program. However, in a textual and legal sense, the linked executable is a combined work, a derivative of the original library, and the ordinary General Public License treats it as such.

    ...

    The precise terms and conditions for copying, distribution and modification follow. Pay close attention to the difference between a "work based on the library" and a "work that uses the library". The former contains code derived from the library, while the latter only works together with the library.

    Terms and Conditions, Clause 0:

    The "Library", below, refers to any such software library or work which has been distributed under these terms. A "work based on the Library" means either the Library or any derivative work under copyright law: that is to say, a work containing the Library or a portion of it, either verbatim or with modifications and/or translated straightforwardly into another language. (Hereinafter, translation is included without limitation in the term "modification".)

    Terms and Conditions, Clause 2:

    These requirements apply to the modified work as a whole. If identifiable sections of that work are not derived from the Library, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Library, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it.

    Thus, it is not the intent of this section to claim rights or contest your rights to work written entirely by you; rather, the intent is to exercise the right to control the distribution of derivative or collective works based on the Library.

    Terms and Conditions, Clause 5:

    A program that contains no derivative of any portion of the Library, but is designed to work with the Library by being compiled or linked with it, is called a "work that uses the Library". Such a work, in isolation, is not a derivative work of the Library, and therefore falls outside the scope of this License.

    However, linking a "work that uses the Library" with the Library creates an executable that is a derivative of the Library (because it contains portions of the Library), rather than a "work that uses the library". The executable is therefore covered by this License. Section 6 states terms for distribution of such executables.

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77 Responses to “WordPress Themes, GPL, and Copyright Case Law”
  1. saulgoode says:

    The Sega court expressly stated that infringement occurred due to the copying of the copyrightable content of the object code, but that such copying was fair use since it was the only means of accessing the non-copyrightable content that was necessary for development of follow-on (and by definition, non-derivative) works.

    I disagree with your definition; basing a work upon non-copyrightable content does not make it non-derivative, it would be derivative but non-infringing. If I produce a photo album of paintings by Leonardo daVinci, it is still a derivative work even though it doesn’t infringe upon any copyrights.

    Semantics aside, I would point out that while the court in the Sega trial did address accessing non-copyrightable content of the object code, they did not actually delineate what that obtained, or why. As such, it is rather a stretch to conclude from that case that modules or plug-ins which inter-operate with programs don’t access copyrightable content; especially so since the “object code” under consideration was machine statements burned into ROM.

    Given the construct of the machine and the development approach taken at the time, there was no function prototyping, no symbolic referencing, and no runtime linking information that could be gleaned from reverse engineering the Sega games’ object code. Aren’t these aspects of a program indicative of the creative and intellectual elements that the programmer has fixated in the software which make it copyrightable?

    Isn’t that precisely what copyright is supposed to protect: the creative and intellectual choices made by an author, artist, or programmer that are distinct from the choices that would be made by somebody else? Certainly Ian Fleming shouldn’t be able to prevent others from writing stories about heroic government agents battling evil villains who are members of global terrorist organizations, but when those stories call their hero James Bond and he works for MI6 and is fighting Ernst Blofield of S.P.E.C.T.R.E. then it pretty well starts to fall under consideration as being a derivative work.

    Likewise, I would argue, that copyright law as applied to computer programs does not preclude people from employing the algorithms and functionality from other programs, but once your program (or plug-in/module) starts calling a particular set of functions with a particular set of parameters in a particular sequence, you have entered the realm of creating a derivative work based on that other computer program*. If the creative and intellectual aspects of a computer program aren’t protectable by copyright then what exactly makes a program copyrightable?

    * But not necessarily infringing.

  2. Chip Bennett says:

    @saulgoode:

    I disagree with your definition; basing a work upon non-copyrightable content does not make it non-derivative, it would be derivative but non-infringing.

    Copyright only extends to that part of a work that is copyrightable. Content can be non-copyrightable for myriad reasons (public domain, copyrighted by others, merger, scenes a faire, etc.); but regardless of the reason particular content is deemed non-copyrightable, if content is determined to be non-copyrightable, then it by definition isn’t copyrighted. If it isn’t copyrighted, then it (again, by definition) isn’t derivative.

    If I produce a photo album of paintings by Leonardo daVinci, it is still a derivative work even though it doesn’t infringe upon any copyrights.

    Assuming the paintings (or the photos thereof) are in the public domain, then you have created a compilation. Your copyright doesn’t extend to the photos themselves, but rather to the creative manner in which you compiled them. Such compilations have a very narrow scope in terms of copyright protection.

    I could take those same photos and do pretty much anything with them – except for re-create your exact compilation – without violating your copyright.

    Semantics aside, I would point out that while the court in the Sega trial did address accessing non-copyrightable content of the object code, they did not actually delineate what that obtained, or why.

    I would argue that such differentiation is exactly what the Sega court performed. See Sega at 1523:

    The declarations of Accolade’s employees indicate, and the district court found, that Accolade copied Sega’s software solely in order to discover the functional requirements for compatibility with the Genesis console — aspects of Sega’s programs that are not protected by copyright. With respect to the video game programs contained in Accolade’s game cartridges, there is no evidence in the record that Accolade sought to avoid performing its own creative work.

    Clearly, the Sega court considered Accolade’s games themselves to be original, creative work (i.e. non-derivative), and considered the “functional requirements for compatibility” to be “not protected by copyright”. This differentiation is directly applicable to a WordPress Theme: the creative expression of the Theme is original, creative work, and the “functional requirements for compatibility” with WordPress (i.e. function calls, filter/action hooks, etc.) are not protected by copyright.

    As such, it is rather a stretch to conclude from that case that modules or plug-ins which inter-operate with programs don’t access copyrightable content; especially so since the “object code” under consideration was machine statements burned into ROM.

    Even if your conclusions regarding the Sega decision are correct (and as I argue, they aren’t), this follow-on conclusion appears not to take Galoob into consideration. The Galoob Game Genie is exactly what you describe: a “[module] or [plug-in] which interoperate[s] with [a] program” – and the Galoob court determined that the Game Genie was not a derivative work.

    Given the construct of the machine and the development approach taken at the time, there was no function prototyping, no symbolic referencing, and no runtime linking information that could be gleaned from reverse engineering the Sega games’ object code. Aren’t these aspects of a program indicative of the creative and intellectual elements that the programmer has fixated in the software which make it copyrightable?

    No. Those are primarily “functional requirements for compatibility” and scenes a faire (see also: Altai).

    Isn’t that precisely what copyright is supposed to protect: the creative and intellectual choices made by an author, artist, or programmer that are distinct from the choices that would be made by somebody else? Certainly Ian Fleming shouldn’t be able to prevent others from writing stories about heroic government agents battling evil villains who are members of global terrorist organizations, but when those stories call their hero James Bond and he works for MI6 and is fighting Ernst Blofield of S.P.E.C.T.R.E. then it pretty well starts to fall under consideration as being a derivative work.

    And thus, you have nicely described scenes a faire – but, it seems, you have mis-applied the concept to WordPress. WordPress is a content management system used primarily as a blogging platform. To repeat two aspects I’ve referenced above: WordPress cannot claim copyright for Widgets and Comments (both are scenes a faire for a CMS/blogging platform). However, the creative expression contained in the code behind wp_list_comments() is copyrightable. Likewise, the actual Widgets included in core WordPress are copyrightable.

    What is not copyrightable, however, is the use of the wp_list_comments() function call. It is merely a method of compatibility. Likewise, extending the WP_Widgets class to incorporate new Widgets is not copyrightable (nor are the new Widgets inherently derivative of WordPress).

    Likewise, I would argue, that copyright law as applied to computer programs does not preclude people from employing the algorithms and functionality from other programs, but once your program (or plug-in/module) starts calling a particular set of functions with a particular set of parameters in a particular sequence, you have entered the realm of creating a derivative work based on that other computer program*.

    Merely making function calls is not derivative, because doing so in no way incorporates copyrightable content of a protected work in a follow-on work. Making those function calls with a particular set of parameters in a particular sequence – if such parameters and sequence are required for interoperability with the program – is likewise not derivative, because such parameters and sequence are “methods of operation” and therefore non-copyrightable.

    If the creative and intellectual aspects of a computer program aren’t protectable by copyright then what exactly makes a program copyrightable?

    That depends entirely on the purpose of the program – and that is a question that, as the Altai court indicated, needs to be answered using a process of Abstraction, Filtration, and Comparison.

    It seems that you are arguing for a Wheelan-level abstraction, which no court in the past 18 years has applied.

  3. RJack says:

    As happens with too many discussions concerning the GPL license,
    there seems to be an automatic assumption that the GPL is an
    enforceable license. Before launching into an analysis of what
    constitutes a derivative work or what constitutes an infringing
    derivative work, why not ask “is section 2 of the GPL license
    legally enforceable?”

    The Software Freedom Law Center has forever claimed that section 2(b)
    is a “condition” on the permissions to copy, modify and distribute GPL
    code. See for example the Best Buy Inc. litigation:

    “23. Under the License, Mr. Andersen grants certain permissions to other
    parties to copy, modify and redistribute BusyBox so long as those
    parties satisfy certain conditions. In particular, Section 2(b) of the
    License, addressing each Licensee, states: 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. Thus,
    if a Licensee redistributes a version of BusyBox, it may do so only
    under the terms of the License. Distribution of BusyBox under any other
    terms or conditions is not allowed.”
    http://www.softwarefreedom.org/resources/2009/busybox-complaint-2009-12-14.pdf

    The term “condition” in a legal complaint means a “condition precedent”.
    We can rest assured that Judge Scheindlin who is hearing the Best Buy
    Inc. case will interpret the term “condition” this way. See e.g.:

    “n52 “Plaintiffs bring claims for “Contract Failure of Condition”
    against each defendant. The Court is not familiar with this term. I
    assume “Contract Failure of Condition” is a claim for breach of a
    condition precedent.” Abu Dhabi Commercial Bank, et al. v. Morgan
    Stanley & Co., et al., 1:2008cv07508, SDNY, (2008).–Judge Shira A.
    Scheindlin. http://amlawdaily.typepad.com/AbuDhabi.pdf

    So… what is a “condition precedent” in a contract?

    “A condition is an event, not certain to occur, which must occur, unless
    its non-occurrence is excused, before performance under a contract
    becomes due.” Restatement (Second) of Contracts § 224 (1981).
    “Conditions precedent are disfavored and will not be read into a
    contract unless required by plain, unambiguous language.” Effects
    Associates, 908 F.2d at 559 n.7.”; Jacob Maxwell, Inc. v. Veeck, 110
    F.3d 749 (11th Cir. 1997).
    http://ftp.resource.org/courts.gov/c/F3/110/110.F3d.749.96-2636.html

    In the case of the GPL, the performance that is subject to the
    conditioning events is in section 2: “You may modify your copy or copies
    of the Program or any portion of it, thus forming a work based on the
    Program, and copy and distribute such modifications…” One event
    (condition precedent) which must be satisfied is section 2(b):

    “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.”

    The obvious question is how you do gain copyright permission to copy,
    modify and redistribute the GPL’d code? You can’t *copy*, *modify* or
    distribute any code unless you *first* satisfy the condition (event)
    that any derivative work “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”.

    So… how do you distribute and license code that you have not yet
    received permission to create (copy and modify)? In contract law this is
    known as an impossible condition — the conditioning event depends on
    performance of the contract and performance of the contract depends on
    the conditioning event.

    Impossible conditions occurring in a contract are strictly construed
    against the drafter. The GPL is truly an unenforceable license.

  4. Chip Bennett says:

    @RJack,

    I’m tracking you now. Thanks for clarifying and elaborating.

    You bring up an interesting question regarding GPL – one that I’d not considered. As such, I’m not really in a position to comment on it. I think the point you bring up is fascinating, but largely irrelevant for the WordPress community at-large, which has generally accepted the validity of the GPL.

    I’ll have to look into it some more.

  5. Alexander Terekhov says:

    Nice article.

    Supported by: Dangerous Liaisons—Software Combinations as Derivative Works? Distribution, Installation, and Execution of Linked Programs Under Copyright Law, Commercial Licenses, and the GPL, By Lothar Determann

    Keep up the good work of disspeling the GPL myths.

    regards,
    alexander.

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