Why aren&#39;t programming languages infringing IEEE&#39;s POSIX trademark? POSIX is a standard for operating system API, trademarked by IEEE. It ensures &quot;source-code&quot; level compatibility between operating systems and applications. It receives triple designation and its full text can be obtained from IEEE, ISO, and OpenGroup. For logical reasons, many programming languages (Python for example) include modules whose name is &quot;posix&quot; (lower-case per identifier naming convention of respective languages). Even though these modules provide functionalities that are specified in the POSIX standard and claim obvious relationship to it, these modules and languages that provide them nonetheless don't infringe the POSIX trademark. So how is this possible?
A caveat to begin with: It's not definitive whether this particular use is or is not infringing, given that the circumstances haven't been tested in court. The usual scope for this kind of thing is called &quot;nominative use&quot; or &quot;nominative fair use&quot; in the U.S. context. The Python developers are offering a software module so that Python programs, when run on POSIX systems, can make use of capabilities of those systems covered by the POSIX standard. They have named their module posix so that Python programmers will have a fighting chance of guessing what it does. (The official documentation does say you ought to prefer use of os instead, but let's ignore that wrinkle.) Likewise, other parts of the standard library contain trademarks of other companies, such as Apple, Microsoft, and Oracle, in relation to Python code which interacts with those companies' products. These are all internal to the Python codebase and documentation, are not distributed separately, and &quot;POSIX&quot; is not part of the name of any product or service offered by the Python Software Foundation. Python is using that word &quot;nominatively&quot;, describing some aspect of Python which relates to POSIX but is not POSIX. The module authors might consider it sensible to use the word &quot;POSIX&quot; in its name and documentation, for the reason that compatibility with POSIX is essential to its functionality. But the rightsholders might also object to its appearance as a bare word (as opposed to posixinterface or something), because they want to preserve the meaning of &quot;POSIX&quot; as referring to their specific standard, the commercial value of which depends on restricting which operating systems can describe themselves as POSIX-compatible. In the U.S., circuit courts have taken slightly different directions in trying to carve out whether trademark use like this is OK. In the Second Circuit, there is a recent case about nominative fair use of a certification mark, Int'l Info. Sys. Sec. Certification Consortium v. Sec. Univ., LLC, 823 F.3d 153 (2d Cir. 2016). The plaintiff, (ISC)2, offers the mark &quot;CISSP&quot; for security professionals who have passed certain examinations that they administer. The defendant, SU, offered training classes where the instructor was described as a &quot;Master CISSP&quot;, to which the plaintiff objected because consumers could be misled into thinking that (ISC)2 endorsed the classes, and their trademark was being diluted because &quot;Master CISSP&quot; is not a term they use. On appeal, the upper court found that for assessing consumer confusion, courts must consider the eight &quot;Polaroid factors&quot; (named for Polaroid Corp. v. Polarad Electronics Corp., 287 F.2d 492 (2d Cir. 1961) and rephrased in the judgement): The eight factors are: (1) strength of the trademark; (2) similarity of the marks; (3) proximity of the products and their competitiveness with one another; (4) evidence that the senior user may “bridge the gap” by developing a product for sale in the market of the alleged infringer's product; (5) evidence of actual consumer confusion; (6) evidence that the imitative mark was adopted in bad faith; (7) respective quality of the products; and (8) sophistication of consumers in the relevant market. and also: (1) whether the use of the plaintiff's mark is necessary to describe both the plaintiff's product or service and the defendant's product or service, that is, whether the product or service is not readily identifiable without use of the mark; (2) whether the defendant uses only so much of the plaintiff's mark as is necessary to identify the product or service; and (3) whether the defendant did anything that would, in conjunction with the mark, suggest sponsorship or endorsement by the plaintiff holder, that is, whether the defendant's conduct or language reflects the true or accurate relationship between plaintiff's and defendant's products or services. Other circuit courts have adopted subtly different phrasings and this divergence has yet to be resolved by the Supreme Court or by Congress. Whether this standard is met in the example of this question is a matter for argument on the detailed facts. In the EU, there is an explicit protection for this specific kind of use, by virtue of Article 14 of the latest trademark directive, Directive 2015/2436 of 16 December 2015: A trade mark shall not entitle the proprietor to prohibit a third party from using, in the course of trade: ... (c) the trade mark for the purpose of identifying or referring to goods or services as those of the proprietor of that trade mark, in particular, where the use of the trade mark is necessary to indicate the intended purpose of a product or service, in particular as accessories or spare parts. Paragraph 1 shall only apply where the use made by the third party is in accordance with honest practices in industrial or commercial matters. The posix library could be regarded as an &quot;accessory&quot; to a POSIX-compatible operating system, in this sense, but is nonetheless within scope if the word &quot;POSIX&quot; is essential to identify what the module does. A key case in the CJEU, concerning a previous version of the Directive but with the same provision, was BMW Nederland BV v Deenik [1999] C-63/97, where a garage owner advertised himself as able to repair BMW cars, with &quot;BMW&quot; being a trademark of the complainants since 1930. The court held that so long as Deenik didn't imply that he had any commercial relationship or endorsement by BMW, he could reasonably use the term &quot;BMW&quot; as part of describing his services. As with the U.S. system, whether there is actual infringement would depend on the precise situation, and the relevant factors end up being pretty similar. That is partly because of conscious international efforts to harmonize trademark law.
When you put a logo that is a legally recognized trademark or servicemark in an acknowledgements section of a document, you are not infringing on the mark. A mark if infringed by someone using it when it is used in a manner that falsely communicates an affiliation with, or an endorsement of, the mark owner of the type of good or service that is protected by the mark. Using a mark in an acknowledgment section doesn't communicate this message (unless, of course, the acknowledgement section falsely says otherwise, which it wouldn't in the case posed by the question). Instead, this use is what is called &quot;nominative use&quot;, and this use also expressly acknowledges and reaffirms that someone else owns the mark and has not licensed it to the author of the work containing the acknowledgement. So, this use of these logos does not infringe on the trademarks or servicemarks that protect these logos.
You really asked two different questions, so let's take them one at a time: Publisher Within the scope of 47 USC 230, Stack Exchange is defined as a provider of an &quot;interactive computer service,&quot; which is defined as follows: Interactive computer service The term “interactive computer service” means any information service, system, or access software provider that provides or enables computer access by multiple users to a computer server, including specifically a service or system that provides access to the Internet and such systems operated or services offered by libraries or educational institutions. Stack Exchange's users are defined as &quot;information content providers&quot;: Information content provider The term “information content provider” means any person or entity that is responsible, in whole or in part, for the creation or development of information provided through the Internet or any other interactive computer service. (Small caps removed to aid in legibility.) Then, under paragraph (c) of that section: (1) Treatment of publisher or speaker No provider or user of an interactive computer service shall be treated as the publisher or speaker of any information provided by another information content provider. (2) Civil liability No provider or user of an interactive computer service shall be held liable on account of— (A) any action voluntarily taken in good faith to restrict access to or availability of material that the provider or user considers to be obscene, lewd, lascivious, filthy, excessively violent, harassing, or otherwise objectionable, whether or not such material is constitutionally protected; or (B) any action taken to enable or make available to information content providers or others the technical means to restrict access to material described in paragraph (1). Therefore, Stack Exchange is specifically and unambiguously excluded from being treated as the publisher of any user-generated content. Additionally, there's an explicit waiver of liability for moderation activities. This waiver does not contain any provision requiring Stack Exchange (or anyone else) to moderate &quot;fairly&quot; or to be &quot;neutral,&quot; nor does it say anything about terms of service. Regardless, it's hard to see how they could violate these terms anyway: Stack Overflow reserves the right to refuse, suspend or terminate your access to the public Network if it determines, in its sole discretion, that you have in any way violated these Public Network Terms or are otherwise ineligible to access or use the Network or Services. If your actions are determined by us to violate these Public Network Terms, Stack Overflow may, in its sole discretion, try to remediate that violation by working with you individually, but is under no obligation to do so, and if any such remediation efforts are unsuccessful (in Stack Overflow’s sole discretion), then Stack Overflow may revoke your rights to the Network. (Emphasis added.) Public forum A &quot;public forum&quot; in American Constitutional law normally refers to a situation where an agent of the government contracts with a private entity to set up a space in which the general public may speak or otherwise express themselves. Because the private entity acts on behalf of the government, the First Amendment is extended to the private entity, at least in the context of the space which it has set up. Stack Exchange, to the best of my knowledge, has no such relationship with either the federal or any state government. So the doctrine is inapplicable. In California, the state constitution has a stronger provision which has been applied to private actors notwithstanding their lack of a relationship with the government. This case was Pruneyard v. Robins. In subsequent California caselaw, the courts have repeatedly refused to extend this logic beyond its original context (shopping malls with &quot;common areas&quot; where people may congregate), and it seems unlikely that it would apply to websites.
My understanding is that here "derived from the program" means "created by modifying the source code of the program" and not "created by running the program". Certainly that is the way all users that I have heard of treat the matter. Note that a commercial program, such as a word processor, will be fully protected by copyright, but the maker does not claim to have any rights over documents written using it. "Derived" here seems pretty clearly to mean "derivative work" in the sense in which that term is used in copyright law. In copyright law "derived work" is a term of art with a definition specific to that field.
The problem is that open source licenses incl AGPL have legal force because copyright prevents copying + modifying software by default (software is treated as a “literary work” and therefore enjoys copyright protection). But copyright on datasets and ML models is very different – if it is even recognized at all. Thus, similar copyleft techniques would only work in particular jurisdictions. For example, the EU recognizes “database rights”. A copyleft license that accounts for this is CC-BY-SA-4.0, meaning that in an EU context, databases based on the original database would have to use the same license. However, database rights are not recognized in the US (facts are not copyrightable, and the “sweat of the brow” doctrine is not recognized). Thus, the CC-BY-SA-4.0 license would not have any copyleft effect with respect to databases in an US context. Independently of copyright in the database as a whole, the data in the database might be copyrighted material, for example if the database contains text or images, complicating matters further. Machine learning models derived from a data set are much more difficult. Clearly, ML models that have been trained are not a creative work and are therefore not eligible for independent copyright protection. At most, it can be argued that the model is an automatically transformed version of the input data, so that copyright in the input data implies copyright in the model.1 Perhaps hyperparameter choices could reflect some creative input. This is very much an active topic of debate. Given this uncertainty, it would be impossible to create a public license that works reliably. 1. An interesting discussion topic is the potential effect on Microsoft's Copilot ML model which was also trained on GPL-licensed source code. Instead of deriving force from copyright law, it would be possible to impose conditions via a contract, i.e. EULA-like terms that only provide access to the material after the terms have been accepted. But again, this is difficult. Contract law differs wildly between jurisdictions. For example, a contract is defined by the “meeting of minds” in some jurisdictions; by offer, acceptance, and consideration in others. But how does such a contract ensure appropriate consideration? How can acceptance be ensured if the material is publicly available? For these reasons, I think that unless broad international agreement emerges about IP protections for machine learning models, such a copyleft system for ML models is impossible. It is worth noting that the lack of such protections is probably quite good for innovation and research, since researchers are free to improve each other's work without legal concerns. The idea of copyleft is a hack to subvert the “everything is forbidden by default” system of copyright, but “everything is allowed by default” might be better.2 2. To continue the Microsoft Copilot example: some copyleft advocates like Bradley M Kuhn are sceptical about Copilot's GPL compliance, but remind us that copyleft maximalism means copyright maximalism, and that this is not the goal of open source. https://sfconservancy.org/blog/2022/feb/03/github-copilot-copyleft-gpl/
Copyright In most (all?) jurisdictions, copyright protects creative expression, not ideas. In united-states doctrine, that is known as the idea-expression distinction, but that concept is not US-specific. Therefore, the text of a recipe, an accompanying image, and other similar elements can be copyrighted. However, the functional parts of the recipe (the exact ingredients, proportions, timing of steps etc.) are not. If the Youtube video reads out the text of the recipe, then it would be a derivative work, but if the script of the video is rewritten in different words, it is not. Even further, the creative elements are only protected insofar as the same underlying idea can be expressed in multiple ways (merger doctrine). The typical example is software code where the level of similarity required to show infringement is high: computer code is text, but that text has to follow strict rules to be valid when run through the computer, and industry best practices mandate additional similarities. Recipes are more flexible than computer code, but they still follow a guiding pattern. Similarities of content that would be considered close paraphrasing (hence infringement) in a free-form context could be deemed to not be infringement in a stricter-form context. For instance, in france, taking the recipes from a children’s cookbook and putting them into another children’s cookbook (in different words but the same &quot;for-children&quot; tone) was deemed to not be infringement: Ces recettes prennent la forme classique et stéréotypée d’une énumération des ingrédients puis d’une description étape par étape des opérations à effectuer. Si (...) la formulation prend en considération le jeune public auquel est destiné ces recettes, cette caractéristique qui n’est au demeurant pas innovante comme le montrent d’autres exemples de recettes destinées aux enfants versés au débat par la défenderesse qui adoptent un ton similaire, ne suffit pas à leur donner une forme ou un contenu qui porte l’empreinte de la personnalité du rédacteur. Aussi les recettes en cause ne relèvent pas d’une activité créatrice originale, et ne sont pas de ce fait protégées au titre des droits d’auteurs. Those recipes take the standard and stereotyped form of a list of ingredients followed by a step-by-step description of the operations to perform. If (...) the choice of words takes its young audience into consideration, that characteristic (which is not new, as proven by other examples of children-oriented recipes shown by the defendant) is not sufficient to give it a form or content bearing the mark of its creator’s personality. As such, those recipes are not considered an original creative work, and are thus not protected by copyright. Source: TGI PARIS 3ème 2ème section 24 janvier 2014 RG 12/00188, cited at this link. Other intellectual property rights Trademarks protect brand image. If John Doe publishes John Doe’s Recipe Book with a recipe for John Doe’s cookies, and fills out the appropriate trademark paperwork, you are allowed to follow the same recipe to make cookies (or another recipe that produces similar cookies), but you cannot sell them as &quot;John Doe’s cookies&quot;. You can say that you followed the recipe of John Doe’s book, but you can not say or imply anything that could make anyone think John Doe approved your cookies. Patents protect inventions, which are novel and non-obvious solutions to (usually technical) problems. I am not familiar enough to know if a particularly inventive recipe could be patentable (I guess not, but the answer might vary across jurisdictions). However, most recipes are new takes on old ideas (add more of that ingredient, less of that, have a different texture etc.). Those are certainly not patentable because they are &quot;obvious&quot; (which, in the context of patent law, means that anyone who has read all existing cookbooks in all languages could imagine the modified recipe). There are other, highly jurisdiction-dependent rights. For instance, in france, the shape and presentation of John Doe’s cookies could be protected under a &quot;dessins et modèles&quot; (sketches and models) clause. (For most recipes, it is trivial to modify the appearance of the final product enough to escape that kind of protection, so it is best thought of as an extension of trademark - you cannot sell John-Doe-looking-cookies even if you make clear they are not John-Doe-approved.)
Not having immediate access to the source doesn't preclude a finding of copyright infringement. If you have seen the source material, subconscious infringement can happen. However, in this example, both the short phrases doctrine and the merger doctrine would likely prevent the is_prime function from having copyright. Words and short phrases are not individually copyrightable, so the name would be free to take. Regarding the implementing code, if it isn't an exact copy (i.e. copy and paste), courts will apply the abstraction-filtration-comparision test. They may find that you took the selection and arrangement of instructions from the original source, albiet using different names. That selection and arrangement would probably be considered a substantial similarity and, if not for the merger doctrine, infringement. However, given the limited number of ways to express the prime-detection algorithm means that the expression of that idea has merged with the idea, and thus is not protected by copyright. (Or in some jurisdictions, merger is a defence to infringement rather than a bar to copyrightability).
Your question mixes up two different aspects of intellectual property. From a copyright point of view, it is perfectly legal to reproduce the features of a one piece of software in another. The functionlity of the software is not copyright (although the detailed look and feel of the user interface might be). However you ask if you, as an employee, can do this by &quot;looking into the code of software X&quot;. Presumably by doing this learn something of the organisation and algorithms used. Even if you avoid direct copying, you are likely to have learned trade secrets of your employer, and publishing these is at least a civil tort in the US, and in some states a crime.