tl;dr version Unlike most software licenses, the GPL (at least version 3.0) does not contain a choice of law provision. Why is this, and what provisions are in place to adjudicate disputes in the meaning, applicability, or enforceability of the GPL or sections thereof in the absence of an authoritative tribunal or legal system?
The vast majority of software licenses provide a choice of law clause specifying that their terms shall be interpreted according to the laws of and enforced by the courts of a specific legal jurisdiction, typically the jurisdiction in which the software publisher is headquartered.
For example, the license for CentreSuite (a product I picked at random, no affiliation) provides that (emphasis in original):
Governing Law and Jurisdiction. You and Provider agree that all matters arising from or relating to the Provider’s provision of the Application(s), Related Services, Information, and your access to and use thereof, shall be governed by the laws of the State of Colorado and the United States, without regard to conflict of laws principles. You and Provider agree to submit to the exclusive personal jurisdiction and venue of the appropriate state or federal court located in Denver, Colorado, USA with respect to all such matters.
These clauses are quite common. Apple software generally includes a choice of law provision of California law. Microsoft prefers that their licenses be interpreted under the laws of Washington State, where they are headquartered.
My understanding is that these clauses are inserted in order to make enforcement of the license by the publisher easier and more certain. The publisher does not need to spend a large amount of time or effort figuring out how their license would be interpreted under the laws of Uzbekistan, Rwanda, or Argentina, as the user has already agreed that the license can only be interpreted and enforced under the courts of Colorado and the US federal government.
I noticed that nowhere in the text of the GPL 3.0 is a jurisdiction mentioned.
Is there a reason why there is no jurisdiction mentioned in the GPL? On the one hand, it makes sense to not tie the GPL too tightly to the whims of any specific political entity, but it also makes me wonder whether there could be some jurisdiction out there whose laws or courts are likely to interpret GPL clauses in ways that are widely divergent from the ways in which they are generally interpreted, or even perhaps find entire sections of the GPL unenforceable.
For example, suppose I am in possession of the object code of a GPL 3.0-licensed work and I approach the author pursuant to Section 6 to demand a copy of the source code. The author responds that they are in Ruritania and that Section 6 is unenforceable in Ruritania under the No Mandatory Software Disclosures (Ruritania) Act 2022. What is supposed to happen? Does Richard Stallman lead an army of Space Marines to topple the Ruritanian government and install a puppet regime loyal to him? Does the FOSS community get together to boycott Ruritania and/or those who hide behind Ruritanian law to do something that the FOSS community does not agree with? Does everyone just sort of shrug and go back to whatever they were doing before?
Alternately, if the Supreme Court of Ruritania rules that the word "work" in Section 0 of the GPL does not mean what it is generally supposed to mean in the FOSS community, but is actually restricted to "content on a physical medium registered with and physically present at a Ruritanian Depository Library or Accredited University of Software Sciences", will the FOSS community respect that the act of Ruritanians sharing GPL software online outside of library and university contexts does not fall under GPL rules since copies of such software are not legally considered "works" in Ruritania?
I do expect that most jurisdictions are going to interpret the GPL in roughly the same way, but lawyers do not generally like the terms most and roughly! One jurisdiction might adopt an originalist approach, interpreting the GPL according to how they feel Richard Stallman would have understood it when he first wrote it. Another might interpret the GPL as a living document whose precise meaning changes according to the consensus of the FOSS community. Other jurisdictions might impose their own rules in interpreting words or phrases of the GPL to comply with their own public policy, rules of interpretation, or political goals.
I did notice Section 12, No Surrender of Others' Freedom, but that refers to cases in which an author or distributor is legally constrained from complying with the GPL. It doesn't seem to apply when an author or distributor has been granted license (pun intended) under their local law to do things that the GPL purports to prohibit, fail to do things that the GPL requires, or interpret the GPL on terms other than those of the consensus of the FOSS community and/or the ex cathedra pronouncements of Stallman and the FSF.
Another way to ask this question is whether the terms of the GPL are supposed to be objectively interpreted according to an existing set of principles of jurisprudence, rules and theories of interpretation and construction, etc. (e.g. by the standards of a specific jurisdiction or system of law), or whether the FSF and/or the FOSS community in general is open to different, regional, or idiosyncratic interpretations of the GPL.
For a practical example of interpretation, Section 8 of the GPL 3.0 specifies that a license may be restored "permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation". Does the FSF and/or the FOSS community assert the right to define what "reasonable means" involves and what means are and are not reasonable, or do they delegate the determination of such to courts and tribunals around the world? Suppose someone has violated the GPL for some software I wrote and I am wondering if notification by singing telegram falls under "reasonable means". Is this a question I should investigate through the open source community, e.g. by calling the FSF or posting on FOSS forums to gauge current community consensus on reasonableness, or is this a pure legal question for my lawyer?