Can anybody create their own software license? For example, there's the GPL license: https://www.gnu.org/licenses/gpl-3.0.en.html And I assume they made it themselves. Can anybody create their own license? That is to say, can I for example create my own license under which I can license software? If so, then I have a followup question: Can you mandate how a software will be released? For example, I'd make this kind of license: This software is licensed under the [INSERT_NAME_LICENSE] you have the right to freely use, distribute and modify the software, under the condition that any derivative software created based on this software, or created by this software, will necessarily also use [INSERT_NAME_LICENSE] and cannot be sold. Also, would the following clause even be legal? Using this software you agree that any work and intellectual property based on or created with this software will be under the [INSERT_NAME_LICENSE] license, even after any and all code from this software is removed in a future update, or even if the work is rebuilt from the ground up Basically saying that if you use software under the [INSERT_NAME_LICENSE] license to create anything, your creation will automatically be under the [INSERT_NAME_LICENSE] license, even if you completely remove all code created by the original software under [INSERT_NAME_LICENSE] in a future update, your derivative work and the intellectual property associated with it will have to be under the [INSERT_NAME_LICENSE] license. Even if they create the exact same work from scratch without the use of my software. Is that even legal?
Can anybody create their own license? That is to say, can I for example create my own license under which I can license software? Yep. It's just a contract granting rights to use a copyrighted work. You can write your own contracts, so you can write your own software license. It's just often recommended that you don't, because common licenses are more well-understood, and inexperienced drafters may make errors that could result in problems, such as unintended restrictions, failing to restrict things that were intended to be restricted, or creating provisions that aren't enforceable in some/all jurisdictions. Can you mandate how a software will be released? Yes. Many software licenses, including GPL, do. The restrictions you describe in your example sound similar to CC BY-NC-SA. Also, would the following clause even be legal? Using this software you agree that any work and intellectual property based on or created with this software will be under the [INSERT_NAME_LICENSE] license, even after any and all code from this software is removed in a future update, or even if the work is rebuilt from the ground up I'm not entirely certain, but &quot;even after any and all code from this software is removed in a future update, or even if the work is rebuilt from the ground up&quot; seems, in my opinion, unlikely to be enforceable—especially &quot;even if the work is rebuilt from the ground up.&quot; How would you differentiate a complete rebuild from a totally new piece of software? More broadly, once your copyrighted code is no longer in the product, there's nothing for them to license from you. It's hard to imagine how you'd be able to claim that you're harmed by someone releasing a new version of a product that used to contain your code under a different license. Without harm to you, there's nothing for a court to redress.
There are two common approaches. The first approach is simply to let copyright law apply. Under the default terms, the IT provider has no rights to copy your software. Running software is allowed, of course, and not a problem that you need to deal with vis-a-vis the IT provider. You still can sue them if they copy your software, even in the absence of a contract. That is the chief function of copyright, after all! The second approach is to allow the customer to subcontract third parties to act on behalf of them, while acknowledging that such subcontracting does not dissolve them from any responsibilities towards you. In other words, if the 3rd party would do something unauthorized, you have a claim towards the customer and they have a distinct but related claim towards their IT supplier.
According to US law, the GPL is a license, not a contract. This means it is valid without consideration, it also means if you are in violation of the license, then you are committing copyright infringement, instead of being in breach of a contract. In Germany, the GPL is a contract. And that's fine, because German law doesn't require consideration for a contract to be valid. It's interesting in that the GPL license doesn't require you to state whether you agree to the license/contract or not. But if you don't agree to the contract then there is no contract, and you have no right to use the software.
Ideas (methods of playing, game mechanics, strategy, goals) cannot be protected by copyright. But any part of a creative work can. So, no copying of drawings, patterns, images, sounds, or the element. I suppose copying the software code is not an issue here, but it can, obviously, also not be copied. And nothing in your game can look like someone's else trademark.
In general, the output of a program is not copyrighted by the author of the program. When you write a novel in Word, Microsoft doesn't own any copyright in your novel. When you prepare financial statements with Excel, Microsoft doesn't own any copyright in those either. There can be exceptions. Some programs (like GNU Bison, a parser generator) actually do output parts of their own source code, and their source code is copyright to the author. To clarify things, GNU made a statement in the license for Bison that officially says they don't have copyright to what it outputs. You should expect programs of this type to have such an exception, and if they don't, maybe ask the author or don't use them.
No, it means you can't copy it. By default, the copyright to a work is owned by its creator, and nobody else is allowed to copy it, or create derived works, without their permission. That permission can be granted by a license. "License unknown" doesn't really tell us anything, but it certainly isn't clearly granting you permission. So you don't have permission to copy, and thus you cannot. You would have to seek permission from the copyright holder. See also If no licence is distributed with an application/source code, what license applies by default if any? (Some jurisdictions do allow for "fair use" exceptions, which allow you to copy a work without permission. You haven't said what jurisdiction you are in.)
The software is "work for hire" and the copyright is owned by the client, not you. This is the default rule when copyrightable work is done on this basis in the absence of an agreement to the contrary. To not be "work for hire" you would have had to have a written agreement to the contrary or would have had to written the software before you were engaged by the client and then sold it to the client as an off the shelf finished product. [After further research I have determined that the language above is not accurate.] While you didn't have a written agreement, you did have an agreement reached without committing it to a final written form signed by both parties that is sufficient to cover all of the material terms of the contract and that is a binding and fully performed agreement. UPDATE: The "work for hire" issue is a bit more complex than I initially stated. Here is an American Bar Association summary of the issue in the independent contractor context (there is also a plausible argument that while the parties characterized you as an independent contractor for tax purposes that you were in fact of de facto temporary employee in which case it would automatically be work for hire, but I'll put that issue aside and take it at face value): Under the Copyright Act (17 U.S.C. §§ 101 et seq.), a work is a “work made for hire” only if: (1) it is prepared by an employee within the scope of his employment; or (2) it is specially ordered or commissioned from an independent contractor pursuant to a written agreement and the work falls within one of nine statutorily defined categories. . . . For works created by independent contractors, only the following types of works are eligible to be “works made for hire”: a contribution to a “collective work” (a work, such as a periodical issue, anthology, or encyclopedia, in which a number of contributions, constituting separate and independent works in themselves, are assembled into a collective whole); a part of a motion picture or other audiovisual work; a translation; a “supplementary work” (a work prepared for publication as a secondary adjunct to a work by another author for the purpose of introducing, concluding, illustrating, explaining, revising, commenting upon, or assisting in the use of the other work, such as forewords, afterwords, pictorial illustrations, maps, charts, tables, editorial notes, musical arrangements, answer material for tests, bibliographies, appendixes, and indexes); a “compilation” (a work formed by the collection and assembling of preexisting materials or of data that are selected, coordinated, or arranged in such a way that the resulting work as a whole constitutes an original work of authorship); an “instructional text” (a literary, pictorial, or graphic work prepared for publication and with the purpose of use in systematic instructional activities); a test; answer material for a test; or an atlas. This software is clearly specially ordered or commissioned from an independent contractor. I suspect that if you looked at the course of dealings including the client's specification of what work needed to be done (probably in part by email or in some other written form) that it would meet the requirement of a written agreement even though there wasn't a document called a contract signed by both parties. But, this still begs the question of whether it falls in one of the nine statutory categories. This American Bar Association source says that custom software doesn't qualify. The list above does not include many types of works that businesses frequently hire outside personnel to create, such as websites, logos, advertisements, photography, and custom software. For works that do fall within the defined categories, the business must have a written agreement from the author expressly stating that the work is made for hire for it to qualify as such. Although the agreement and course of dealings between a business and an independent contractor may give rise to an implied license for the business to use the works created by the contractor, it is highly preferable to avoid relying on an implied license. Any business that engages a non-employee to create a work and intends to own the copyright to such work should have a written agreement with the author expressly stating that the work is made for hire (if it falls within one of the eligible categories). If the work is not eligible to be a work made for hire, and for good measure even if it is, the written agreement should include a provision assigning the copyrights to the business. An example of such a provision is: “To the extent that the Work Product is not recognized as a ‘work made for hire’ as a matter of law, the Contractor hereby assigns to the Company any and all copyrights in and to the Work Product.” By including such a copyright assignment clause, a business will be able to obtain the copyrights it expects, even if the work does not qualify as a “work made for hire.” The copyright office's official publication on the subject provides a statutory citation (17 USC 101), and doesn't contradict the ABA presentation, although it is less detailed and specific on the legal issues. This section of the United States Code is a series of definitions. The relevant one states: A “work made for hire” is— (1) a work prepared by an employee within the scope of his or her employment; or (2) a work specially ordered or commissioned for use as a contribution to a collective work, as a part of a motion picture or other audiovisual work, as a translation, as a supplementary work, as a compilation, as an instructional text, as a test, as answer material for a test, or as an atlas, if the parties expressly agree in a written instrument signed by them that the work shall be considered a work made for hire. For the purpose of the foregoing sentence, a “supplementary work” is a work prepared for publication as a secondary adjunct to a work by another author for the purpose of introducing, concluding, illustrating, explaining, revising, commenting upon, or assisting in the use of the other work, such as forewords, afterwords, pictorial illustrations, maps, charts, tables, editorial notes, musical arrangements, answer material for tests, bibliographies, appendixes, and indexes, and an “instructional text” is a literary, pictorial, or graphic work prepared for publication and with the purpose of use in systematic instructional activities. In determining whether any work is eligible to be considered a work made for hire under paragraph (2), neither the amendment contained in section 1011(d) of the Intellectual Property and Communications Omnibus Reform Act of 1999, as enacted by section 1000(a)(9) of Public Law 106-113, nor the deletion of the words added by that amendment— (A) shall be considered or otherwise given any legal significance, or (B) shall be interpreted to indicate congressional approval or disapproval of, or acquiescence in, any judicial determination, by the courts or the Copyright Office. Paragraph (2) shall be interpreted as if both section 2(a)(1) of the Work Made for Hire and Copyright Corrections Act of 2000 and section 1011(d) of the Intellectual Property and Communications Omnibus Reform Act of 1999, as enacted by section 1000(a)(9) of Public Law 106-113, were never enacted, and without regard to any inaction or awareness by the Congress at any time of any judicial determinations.
The Free Software Foundation considers that the Apache 2.0 license is compatible with the GPL 3.0: This is a free software license, compatible with version 3 of the GNU GPL. But not compatible with the GPL 2.0, though: Please note that this license is not compatible with GPL version 2, because it has some requirements that are not in that GPL version. These include certain patent termination and indemnification provisions. The patent termination provision is a good thing, which is why we recommend the Apache 2.0 license for substantial programs over other lax permissive licenses. But what does it mean when the FSF says a license is &quot;compatible with the GPL?&quot; It means that the other license and the GNU GPL are compatible; you can combine code released under the other license with code released under the GNU GPL in one larger program. All GNU GPL versions permit such combinations privately; they also permit distribution of such combinations provided the combination is released under the same GNU GPL version. The other license is compatible with the GPL if it permits this too. GPLv3 is compatible with more licenses than GPLv2: it allows you to make combinations with code that has specific kinds of additional requirements that are not in GPLv3 itself. Section 7 has more information about this, including the list of additional requirements that are permitted. So what can you make of this? The FSF considers these two licenses compatible and it also means that when you combine code under these two licenses, the effective obligations that will apply are these of the Apache and GPL combined, including source code redistribution. But why are the compatible? Is the fact that the FSF says so enough? We can check what the Apache Software Foundation says on the topic: The Free Software Foundation considers the Apache License, Version 2.0 to be a free software license, compatible with version 3 of the GPL. The Software Freedom Law Center provides practical advice for developers about including permissively licensed source. Apache 2 software can therefore be included in GPLv3 projects, because the GPLv3 license accepts our software into GPLv3 works. So irrespective of the deeper why, they tend to agree and as they are the authors of the respective licenses, this carries some weight. But wait, this is not true the other way around as the ASF goes on: However, GPLv3 software cannot be included in Apache projects. The licenses are incompatible in one direction only, and it is a result of ASF's licensing philosophy and the GPLv3 authors' interpretation of copyright law. So in a nutshell, the FSF considers that the terms of the Apache license are compatible with the copyleft terms of the GPL 3.0. The ASF agrees, but the copyleft terms of the GPL 3.0 are not compatible with the permissive terms of the Apache 2.0: a combination of the two would have to be copyleft.