This article is the third in a four-part series focusing on open content licensing, particularly the copyleft regime under Version 2 of the GNU General Public License (GPL). This part discusses the challenges in identifying the governing law and the safe harbour exceptions to the copyleft obligations of the GNU GPL.

McCarthy Tétrault Notes:

Many individuals in the software industry, and even in legal practice, readily assume that the GNU GPL will be interpreted and governed by US law under all circumstances, given that it originated in the Unites States. However, the GNU GPL is merely akin to a licensing template or drafting precedent. For operative licensing, its terms are required to be specifically adopted by the relevant copyright owners of the material intended to be licensed under it.

As with any other matter of contract law or tort law, and absent a valid selection of law by the parties involved, the appropriate governing law in any given context of distribution under the licensing terms of the GNU GPL will depend on a number of connecting factors that point to the jurisdiction with a real and substantial connection to the matter at hand. These include the respective domiciles of the copyright owners and licensees, the places where the software was authored, and the respective jurisdictions in or from which the software was distributed and used.

The foregoing analysis could be rendered more complex by taking into account that multiple contributors to a work that was originally licensed under the GNU GPL may engage in further development and distribution activity in other jurisdictions than those in which the licensed software was originally distributed under the license. To take the simplest scenario, however, it is hard to conceive that US law would govern the interpretation of the GNU GPL in a situation involving software authored and owned in Canada, where such software is distributed under the GNU GPL and used in Canada.

Issues of conflicts of law pertaining to open content licensing are beyond the scope of this article, but one should always bear in mind that the governing law of the GNU GPL may vary from situation to situation. When considering questions of compliance with the GNU GPL in a critical business context, it is often appropriate to hedge a legal analysis across multiple jurisdictions having some conceivable relevance to the circumstances. An appropriate course of action can then be determined according to the law of the jurisdiction whose law is the most onerous or unfavourable regarding the issues at hand.

Safe Harbour Exceptions to the Copyleft Obligations of the GNU GPL

We now address the second stage of our two-part analysis for determining whether a particular utilization of software code subject to GNU GPL will attract the copyleft obligations of the license in respect of a resulting work that incorporates all or a part of the originating open source material. Having determined under relevant law that the utilization of the licensed open source code ordinarily constitutes an actionable infringement of copyright, one then proceeds to an analyze whether any safe harbour considerations make the prima facie actionable activity otherwise permissible. As discussed in the last issue, these may be found in (i) the operative language of the GNU GPL, (ii) the associated GPL FAQ as published by the Free Software Foundation, or (iii) any other authorizing and binding pronouncement made by or on behalf of the relevant copyright owners for the open source material in question.

As an example of the first type of safe harbour exception, the express language of the GNU GPL indicates that the mere aggregation of another work with a work based on the licensed open source software on a common volume of a storage or distribution medium does not attract the application of the copyleft provisions of the license to the other work. Thus, a collective work as understood in the sense of the license likely requires that the constituent works forming part of the collective work make up a unitary contextualized whole. In this case, the constituent works are otherwise identifiable from one another. For the reasons explained previously, this interpretation is consistent with the nature of collective works under Canadian copyright law.

The language of the GNU GPL that allows for mere aggregations of works to escape the copyleft requirements of the license may provide a false sense of comfort. One must always bear in mind that some software works may start out as a permissible aggregation of works on a substrate or other volume at the time of distribution of a software product. But thereafter, they may impermissibly combine during the compilation or execution of the product to form a derivative work that would be caught by the GNU GPL copyleft provisions under the license. For instance, two separately distributed software works of a product may be merged into a single executable upon compilation. These works may ultimately execute together as a unitary whole within the same address space during the runtime of the compiled product. This would prima facie offend the literal language of the GNU GPL, as the combined works during compilation or runtime would constitute infringing reproductions of the licensed work under copyright law.

The second type of safe harbour exception is found in the language of the GPL FAQ. As its name implies, the GPL FAQ is a series of comments couched in question-andanswer format. These comments provide some practical guidelines and assistance for interpreting and applying the various provisions of the GNU GPL.

It remains uncertain whether the terms of the GPL FAQ can, in every given circumstance, be considered binding and enforceable at law in respect of a particular adoption of the terms and conditions of the GNU GPL by a copyright owner of licensed open source material. Suffice it to say that practitioners versed in open source licensing, as well as their clients in the software industry, have frequent recourse to the GPL FAQ in addressing legal issues that arise with open source licensing under the GNU GPL.

For licensed software under the GNU GPL, of which the underlying copyright is owned by the Free Software Foundation, it is not inconceivable to surmise that the GPL FAQ becomes ancillary to the GNU GPL’s terms and conditions: both documents are produced and promoted by the same entity and made available by it on the same website. Further, one can presume that any interpretive guidance found within the text of the GPL FAQ is likely to be binding as against the Free Software Foundation, whether by express contractual adoption or by way of the operation of the doctrine of estoppel.

Where a copyright owner other than the Free Software Foundation has adopted the template terms and conditions of the GNU GPL in the licensing of an open source software product, it becomes more difficult to argue that such unrelated third parties have also incorporated the GPL FAQ together with their acceptance of the GNU GPL. In such circumstances, it may be challenging to establish the grounds of express contractual adoption or estoppel as may apply in the case of software licensed by the Free Software Foundation.

What can be argued, perhaps, is that dependence on the GPL FAQ for guidance in resolving legal issues surrounding open source software licensing is so prevalent in the legal community and in industry that its terms constitute a “usage of trade” or “custom.” This would render the language of the GPL FAQ binding on the open source licensor as a matter of contract law.

Establishing a practice or activity as a “custom” or as “customary” entails a heavy evidentiary burden. Such practices or activities typically rise to the level of custom only if they are regularly observed by “long and unvarying habit.” Canadian courts have required a showing that a custom or usage be “notorious and certain” before they will accommodate it. Along the same lines, the Uniform Commercial Code refers to custom as a “usage of trade” and limits it to “activity having such regularity of observance in a place, vocation or trade as to justify an expectation that it will be observed.” Notwithstanding this high threshold for finding a custom or usage of trade, the recourse to the GPL FAQ has been so widespread and accepted by lawyers and their clients alike that the wholesale incorporation of its terms into the GNU GPL would not be unreasonable or unwarranted, even with respect to third-party adoptions of the GNU GPL.

An important example of a safe harbour exception, which is grounded in the GPL FAQ, is the one that permits both open source and proprietary programs to be executed together without attracting the copyleft obligations of the GNU GPL, if the two types of programs communicate at arm’s length.

In general, the GPL FAQ provides a twostep test to determine whether an open source program that has been licensed under the GNU GPL is being utilized in a sufficiently separate and isolated manner with an existing proprietary product so as to avoid the imposition of copyleft obligations to the combined whole. The relevant commentary of the GPL FAQ indicates that the determination is made by taking into account first the mechanism of communication between the two program types, and second, the semantics of that communication.

Regarding the mechanism of communication, the GPL FAQ considers that if the two programs are included in the same executable file or are designed to run linked together in a shared address space, the result would be a combined program or derivative work within the meaning of the GNU GPL. The copyleft obligations of the license would then be imposed on the proprietary software forming part of the combined program, with the attendant consequences of having to meet the source code disclosure requirements under the GNU GPL.

On the other hand, the GPL FAQ states that certain specified communication techniques between the two programs, such as the use of pipes, sockets and command-line arguments, indicate a degree of separateness that would not ordinarily attract the copyleft obligations of the license for any proprietary software that interacts with open source software solely in this manner.

Nevertheless, with respect to the second leg of the test, the GPL FAQ indicates that sufficiently intimate semantics of communication between an open source program and a proprietary program will militate in favour of a finding of a combined program. In this situation, the copyleft obligations of the GNU GPL would be imposed in relation to the proprietary software. The two programs in question would then effectively become a single program, notwithstanding the adoption of acceptable mechanisms of communication that would otherwise promote separateness between the two programs. As an example of semantics for communication that result in a single combined program for purposes of the GNU GPL, the GPL FAQ states that the exchange of complex internal data structures between two programs would so qualify.

The final form of safe harbour exception may be pronounced by the copyright owner. This form falls outside of the template terms and conditions of the GNU GPL and is external to the GPL FAQ, both of which we have previously described. For instance, in adopting the GNU GPL for the distribution of software according to the open source model, a copyright owner may make specific exceptions or exclusions to permit various combinations of open source software with a proprietary product, and to ensure that the copyleft obligations of the GNU GPL are thereby avoided in respect of the proprietary program.

Perhaps the best-known example of this type of safe harbouring is a so-called “clarifying note” to the GNU GPL, which Linus Torvalds allegedly put forward in relation to Linux software. The note in question assured the developer community that proprietary-user programs making use of Linux kernel services by way of normal system calls would not fall under the heading of a derived work for purposes of the GNU GPL.

This type of external statement may very well be binding on its maker, once again as a matter of contract law or estoppel. But in order to have any practical benefit, the statement must emanate from the entirety of the owner or owners of copyright in the licensed work at the time the statement is made. In the case of open source software, the many numbers of potential contributors to an open source product may make such attribution difficult.

It is not clear, for instance, that Mr. Torvalds was the sole owner of all of the Linux components potentially affected by the safe harbour exception when the exception was advanced.

Timing is of consequence because a copyright owner may validly pronounce a safe harbour exception at a specific time when all copyright and moral right in an underlying work reside with that owner. Should other third parties thereafter come to handle the underlying work and modify it for redistribution to others, their involvement with the work and subsequently that of other third parties will be subject to the very same terms and conditions as those of the underlying work. This of course follows from the copyleft nature of the GNU GPL.

On the other hand, if the copyright owner of the underlying work licensed under the GNU GPL makes a safe harbour pronouncement after third parties may have contributed modifications to the work, the pronouncement would not be expected to be binding on those third parties. Moreover, it could very well constitute a contravention of such parties’ rights to the modifications in the work as protected by the originating terms and conditions of the GNU GPL prior to the attempted pronouncement.

While this article has focused on the problems inherent in the copyleft requirements of the GNU GPL, many more concerns and challenges with open source licensing exist. These will be introduced in the next instalment of this article.