How are open source licenses valid without consideration? I'm not a lawyer or law student in any capacity, but I've read in multiple sources that a contract is not valid unless there is consideration for both parties. With this in mind, how can licenses for free and open-source software be considered valid? There is no consideration for the developer. I'm interested in all western jurisdictions (e.g. US, EU) but if your answer focuses on just one that's more than fine.
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.
It's possible that CAD has a separate licence from the authors of ABC that allows them to produce a closed source copy. If not, they have no right to distribute CAD. However two wrongs don't make a right, and so you don't get to violate the copyright of CAD.* Unfortunately, unless you are one of the authors of ABC, you have no standing to sue the authors of CAD. You can only notify the authors of ABC and hope they do. If the authors of ABC don't have the resources to pursue the matter, you may be out of luck. That's one of the reasons the FSF gets copyright assignments for their projects. * It turns out that this is a much more debateable issue than I first thought. Some courts have held that an unauthorized derivative work is not copyrightable.
To answer the question in your title: Yes, software licenses are copyrighted. They are written works that involve (significant, expert) creative effort to create. The best solution would be for Grammarly to hire a lawyer and say "we want a new EULA. We think this one covers a number of points our current one doesn't". Most legal documents will be copyright for the same reason (there may be a few that are so stereotypical that there is essentially no creative effort in putting them together).
While the Commons Clause is not an Open Source license, the BSD license allows you to do this. To be clear, you cannot change the license of other people's code. You can however add your own code and license it under whatever terms you want. The resulting code then consists of your modifications, under whatever license you want parts of the original code, under BSD-3-clause Since you are a license-taker for the BSD-3-clause material, you must still comply with its license such as providing any recipients with the copyright + license notice. When people receive the software with your modifications, they must comply with both your chosen license terms for your modifications, and with the BSD-3-clause license for the other parts. For example, you can use the Commons Clause to prevent certain competing uses of the software as a whole. But since you will presumably provide the source code of the software, other people are free to use the BSD-3-clause code under the terms of that license, ignoring your restrictions. If you provide binaries then the resulting binary would not be covered by the BSD-3-clause license, but you would still have to provide the copyright and license notice for the original code as a kind of attribution.
The GPL does not explicitly specify a time within which the source code must be provided, which probably means a &quot;reasonable time&quot; is allowed. What is &quot;reasonable&quot; would eventually be evaluated by a court, if the matter ever got that far. But please note that only the copyright holder (or the holder's authorized agent) can sue for infringement. The license does not give other people a right to sue for infringement, and I doubt that any license could grant such a right. One could inform the copyright holder who could sue, but the holder need not sue, and undertaking such a suit would involve expense, time, and effort. Whether the offer to provide the source constitutes a binding agreement is not clear, and may well vary in different jurisdictions. The question does not state any particular jurisdiction.
is this even legal? It is legal, but at the same time the contract is voidable by you. This means that if the buyer rejects the EULA, he is entitled to return the unused product and be reimbursed. Obviously once the buyer has used the product, the conclusion will be that he accepted the EULA and therefore no longer can void the contract. The buyer's entitlement to rescind the contract compensates for the fact that he was not duly informed about the conditions prior to making the purchase.
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.)
A document can be distributed under more than one license. Just because it has been made available under a CC license for free, doesn't mean that IEEE can't negotiate a different license with different terms that allow them to sell the content. (This is similar to the way that a software library can be available for free under a license that permits non-commercial use, but also be made available for a fee for commercial use.) If you want to know whether IEEE is legally selling Aaron Swartz's manuscript, you can contact Morgan &amp; Claypool, the publisher that owns the copyright, and ask them whether this use by IEEE has been authorized by them. For the other documents you mention, contact MIT Press. Etc.