Is it illegal to copy commercial software features into an open source project? Imagine I work for a company that has a software X, no algorithm in this software is patented. If I want to create an open source software Z that has similar features as software X by looking into the code of software X and recreating the logic would that be illegal? Consider that software Z would be created using different technology, different programming language and would not have copy-pasted code from X.
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.
We can't really know until the ruling is made. The Supreme Court might issue a ruling that encompasses all software APIs, or may predicate its ruling on this more specific situation, e.g. that because Oracle's library is so extensive its structure can be copyrighted even if that does not necessarily mean that any individual function signature can be copyrighted. They could also decide based on something unrelated to the heart of the copyright question - skimming through the petition for a writ of certiorari, they could make a decision based on the original implied license from Sun, for example. Hopefully their decision will answer the copyright question of function declarations completely, but it isn't required to.
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.
All your work is yours. They've made it very clear it wasn't a work for hire, so it's yours. They can't copyright any of their ideas. You can't copyright an idea. Only specific creative elements authored by them and present in your work could be covered by copyright. You didn't use their block diagrams. I don't see how references to other sites to look at would constitute a creative element they authored. That said, you probably want to talk to a lawyer and get a written legal opinion that you can rely on.
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Probably Not The creator or owner of a piece of software does not in general have any copyright over the output when others run the software, unless that output is itself a derivative work of input supplied by the copyright owner, or forming part of the software. In this case the translation is a derivative work of the 19th century original, but that is assumed to be in the public domain. SAo google has no copyright on the resulting translation. But copyright protection is only available for &quot;original works of authorship&quot;. (See 17 USC 102 in the US, and similar laws elsewhere.) A machine-produced translation is not an original work, and it is surely not then work of the author of the overall book. However, the author would still have a copyright on the book as a whole. The legal situation is no different than if the author had simply quoted a 19th century work. One may incorporate public domain works into a later work, and that later work is still protected by copyright, provided that there is enough original contentr to make the work as a whole &quot;an original work of authorship&quot;. Others may use the PD [arts, or the original from which they are taken, but not the rest of the work (beyond what fair use would allow in any case). For example, I have made a number of posts here on LAW.SE. In several,of those I quoted sections from one of the numbers of The Federalist. That 19th century work is in the public domain. Anyone else may re-quote the passages I quoted from it. But that gives them no rights to use the rest of my work, except as the CC-BY-SA license or fair use permits. So the author would retain copyright on the book as a whole. But soemoen who merely quotes or uses the translated 19th century article but none of the original parts of the book would not be infringing that copyright. I say probably in the header, because I do not have any actual case-law to cite here. It is possible that some court has rules otherwise on the subject of the copyright on the output of a software tool, but I strongly doubt it.
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.
Facts cannot be copyrighted. Such a project does not violate copyright law, and if you're in the United States, it is protected by the First Amendment.