Copyright of retyped public domain text In order to copyright something, you have to do an innovative change (photocopying doesn't count) Does converting public domain images into text (through OCR or like wikisource) count as "innovative change" and put a copyright on the resultant text?
A thing needs to be original in order for it to get copyright protection. 17 USC §102: "Copyright protection subsists [...] in original works of authorship" Copyright Act Section 5 (1): "copyright shall subsist in Canada [...] in every original literary, dramatic, musical and artistic work..." In the US, originality requires "a modicum of creativity" (Feist Pubs., Inc. v. Rural Tel. Svc. Co., Inc. 499 U.S. 340 (1991). In Canada, originality requires an "exercise of skill and judgment" and that "not be so trivial that it could be characterized as a purely mechanical exercise" (CCH Canadian Ltd. v. Law Society of Upper Canada, [2004] 1 SCR 339). Text transcribed from a public domain source would not be given copyright protection.
The code is copyrighted. You are not given any permission to use or copy any part of it, nor to create a derivative work based on it. There is no way for you to "make the copyright null". The code was copyrighted in 2005, and the copyright will not expire until 70 years after the death of the author, under US law. The period would vary in some other countries, but in no country that I know of will it expire in the next few years. That the author is dead, or the publisher out of business, does not change this legally. Someone, probably the author's heir, or perhaps whoever bought the remains of the publisher's business, will own the copyright. However, the ideas and programming techniques shown and discussed in the book are not protected, and you may use them freely to write programs, commercial or non-commercial. You need not even acknowledge the book as a source of ideas, although to do so would be nice. Of course, since the author is dead and the publisher not active, if you were to infringe the copyright by copying code from thsi book, there is a reasonable chance that no one would notice, but if someone did notice, the current owner of the copyright could sue you for infringement, and could perhaps win sizable damages. It would be safer to write your own original code using only the general ideas from the book. In future, do not ever assume that you can just take someone else's code (or other creative work, such as a book) and reuse it without permission, unless it is in the public domain, for example because it was published before 1923.
I'm assuming that you are not seeking to change the license, and so it will remain GPLv3. As long as you've built on the original software, that license still applies. You also need to keep the previous copyright notices, including the names of the original people. Assuming that, everything you're doing is legal, which is what's on topic here. There is some etiquette around forks (which is what you're doing), which would be on topic at the Open Source Stack Exchange. I'm puzzled by your desire to have a different license text. You can't change the license from GPLv3, so that has to stay the same. (If the original has GPLv3 "or, at your option, any later version", you can drop the any other version text if you like.)
You don't say where you are located. Copyright laws are different in different countries, am going to assume US laws. Under US law, a faithful digitization of a book does not get a new copyeight, see Bridgeman Art Library, Ltd. v. Corel Corp., 25 F. Supp. 2d 421 (S.D.N.Y. 1998) and thw Wikipedia article about that case (On the issue of mrequired originality, see also FEIST PUBLICATIONS, INC. v. RURAL TELEPHONE SERVICE COMPANY, INC. (No. 89-1909.) (1991) which dealt with copying a telephone directory.) The court in Bridgeman held that: It is uncontested that Bridgeman's images are substantially exact reproductions of public domain works, albeit in a different medium. The images were copied from the underlying works without any avoidable addition, alteration or transformation. Indeed, Bridgeman strives to reproduce precisely those works of art. ... The mere reproduction of a work of art in a different medium should not constitute the required originality for the reason that no one can claim to have independently evolved any particular medium.'&quot; As discussed above, the law requires &quot;some element of material alteration or embellishment&quot; to the totality of the work. At bottom, the totality of the work is the image itself, and Bridgeman admittedly seeks to duplicate exactly the images of the underlying works. ... [O]ne need not deny the creativity inherent in the art of photography to recognize that a photograph which is no more than a copy of the work of another as exact as science and technology permit lacks originality. That is not to say such a feat is trivial, simply not original. The more persuasive analogy is that of a photocopier. Surely designing the technology to produce exact reproductions of documents required much engineering talent, but that does not make the reproductions copyrightable. The Bridgeman court was actually construing UK law, but the earthlier phase of Bridgeman i and the SCOTUS case of Feist show the same result under UIS law. Note that books and other works published before 1925 are now out of copyright in the US. Copyright can also be lost ion other ways, such as publishing without a copyright notice before the effective date of the 1976 act, and failure to properly renew a work published in the US before 1964. Assuming that the book is not under copyright, neither the library nor anyone else has a US copyright in the PFD. Unless the library imposes some additional restriction by contract, any such PDF may be copied or shared freely. It may even be sold or rented. And the validity of such an additional agreement would be questionable, but since the question does not mention such an agreement, I will not go into that further.
You automatically have copyright protection for what you create. A collection of numeric answers to math equations probably would not qualify (lack of requisite creativity), but certainly anything that counts as a "paper" is protected.
Usually not, usually Translating literary works is generally regarded as an adaptation, but I don't think translation programs—and HTML and Markdown, two markup languages with similar principles—are adaptations. According to the description on Creative Commons, Merely changing the format never creates a derivative. So changing WAV to MP3 is not considered an adaptation, nor is changing DOC to PDF. As for HTML and Markdown, it seems a bit vague, but it can be said that although their encoding methods are different, the results presented are very similar. According to https://creativecommons.org/faq/#when-is-my-use-considered-an-adaptation, a modification rises to the level of an adaptation under copyright law when the modified work is based on the prior work but manifests sufficient new creativity to be copyrightable Adaptation produces a derivative. A derivative contains both the will of the original author and the adapter. Creation involves choice, the painter chooses the colors to use, and the translator chooses the words to translate. There are inherently fewer options to create a program. Rendering markdown to html can be done directly through other programs, and it is difficult to see the shadow of the adapter. Editorial originality is very import. Yet one more thing is important: legal definitions. This is what it says in the https://creativecommons.org/faq/#what-is-an-adaptation FQA page What constitutes an adaptation depends on applicable law So, the laws of where you live still matter. We all know that there is a large gray area in copyright law, which often makes everything depend on the actual situation. This is just a little bit of my personal thoughts for your reference :)
No. The images are copyrighted, and you are using them in a way that would leave you with virtually no argument for fair use. The factors for fair use are set out in 17 USC 107, and they indicate that the courts would reject your use: The purpose and character of the use, including whether it is of a commercial nature or for nonprofit educational purposes: There's no indication that your use would be for nonprofit or educational purposes. The nature of the copyrighted work: Works of fiction and art are highly creative works at the heart of the policy for copyright protection. The amount of the portion used in relation to the copyrighted work as a whole: You are apparently copying entire images, though I suppose you could argue that each image is just one small portion of a larger book or website. The effect of the use upon the potential market for or value of the copyrighted work: You are trying to create a board game, putting yourselves basically in direct competition with the makers of D&amp;D. I generally prefer a pretty liberal interpretation of what constitutes fair use, but this just has virtually nothing that would make me comfortable arguing in your favor.
If you create a new work that is derived from or based on someone else's work, it is a derivative work, and you cannot do so without permission from the original copyright holder. If the original work is made available under a CC-BY_SA 4.0 license, you have permission, but it comes with conditions. One of those is that you must attribute the original work -- you must say what work yours is based on and who created it. Another is that you must license your own derived work under the same CC-BY-SA license (or a compatible one). This does not mean that your work is not copyrighted -- it is. But it does mean that you must grant to others the same rights that the creator of the work you used granted to you. That is what the "share alike" or SA part of the license means. if you don't like that, you should not use a work licensed under CC-BY-SA terms to create your own work. If you publish your work but fail to grant that license to others, you are infringing the copyright of the work you used, and could be sued. Note that if you had created a compilation rather than a derived work -- for example if you created an album of images from various sources, some of them under CC-BY-SA licenses, you would retain a copyright on the collection as a whole, and that would not have to be under CC-BY-SA. But in this case you say that you used the other person's image as a background for your own illustration. That is creating an "adapted" or derivative work, i am fairly sure, and invokes the share alike clause of the license. You might also want to consider the different case mentioned in If I include an unmodified CC-BY-SA work in a book, does the whole book have to be CC-BY-SA?