63

I always look at the schema drawn by David Wheeler: Essay: FLOSS licenses The arrows show which license you can use in the context of another license. For instance: you can use software distributed as ASL 2.0 inside an LGPLv3 project and (a fortiori) inside a GPLv3 or AGPLv3 project. You can't use LGPLv3 software inside an ASL 2.0 project. Just follow the ...


50

You can freely issue additional licenses to your own GPL software, without restriction. Licenses can either give an exclusive or non-exclusive right. For example, an employment contract will typically give the employer exclusive rights to whatever the employee produces as part of their work. But the GPL is non-exclusive, thus allowing multiple licenses for ...


46

I cannot say whether this would be considered open source, but it would not be free software. Free software confers, amongst other things, the right to modify the software; the FSF refer to this as freedom one. It imposes, and allows of, no constraint in the application of this right; constraints on the four freedoms are generally allowed only when they ...


37

For me, this exposes a weakness in the mental model many coders seem to have about the operation of copyright. Consider a pile of bricks, representing code contributions to a work. In one (surprisingly common) model, each brick is painted in a colour representing its licence status; red for BSD, blue for GPL, green for Apache, and so on. Whoever made and ...


28

Firstly, since you are the sole author you are (presumably) the sole rightsholder, so you aren't bound by the licence anyway. Secondly, licences don't inhere in software, they attach to software through the process of conveyance. As the rightsholder, you may give one copy to Alice under the terms of GPLv2, and she may use it only under those terms. You ...


23

No; incorporating or linking against GPL requires that your project-as-a-whole be distributed under GPL. But you can include MIT licensed parts (or another GPL-compatible license) in the project. Also, it depends. The pertinent clause is 5 (c): c) You must license the entire work, as a whole, under this License to anyone who comes into possession of a ...


18

Stack Overflow contributions (and all of Stack Exchange's too) are licensed under CC-BY-SA 3.0. That basically means that You are free to Share — copy and redistribute the material in any medium or format Adapt — remix, transform, and build upon the material for any purpose, even commercially. The licensor cannot revoke these freedoms as long as you follow ...


18

The short answer is no. You cannot remove a BSD license notice, otherwise you are no longer licensed per the BSD (many variants) that all share the essential requirement to retain the copyright and license/notice texts in source and/or binaries. If you look at a BSD variant text from wikipedia: 1. Redistributions of source code must retain the above ...


18

Do not use non-standard opensource licenses The other answers are great, and show that what you want to do is probably not too far down an OSS route but here is a different viewpoint. There's a reason you use MIT license at the moment, because it fits (the majority, noted) of license requirements you are happy to put on your project. Others who use OSS ...


18

The CC-BY-SA 3.0 license is “forward compatible” with later versions. In section 4(b): You may Distribute or Publicly Perform an Adaptation only under the terms of: (i) this License; (ii) a later version of this License with the same License Elements as this License; (iii) a Creative Commons jurisdiction license (either this or a later license ...


16

Be careful with the claims about the CDDL on the FSF website, they are wrong. Some years ago, Eben Moglen confirmed to me in a private mail that the claims about the CDDL on the FSF website are based on a false assumption on how BSD / GPL compatibility may be avowed. So the BSD text and the CDDL text on the same website both do not apply. I asked Moglen to ...


15

It is unacknowledged by the FSF, but was approved by the OSI in 2007. There are two main problems with "custom licenses": ghettoization - where the custom license creates its own ghetto with code that nobody else can use because of license incompatibilities legal hazards - where the terms of the license is not precise enough to be usable in litigation The ...


15

Both the GPLv2 and the GPLv3 have clauses that Require the combined product to adhere to the license terms of the license of the GPL licensed component. Require that no additional restrictions may be placed on the combined work: from clause 6 of the GPLv2: Each time you redistribute the Program (or any work based on the Program), the recipient ...


14

Yes, you can use a GPL3 library [1] in an AGPL3 program [2]. You can also cut-and-paste GPL3 code into an AGPL3 program. Both the ordinary GNU GPL, version 3, and the GNU Affero GPL have text allowing you to link together modules under these two licenses in one program. (from https://www.gnu.org/licenses/why-affero-gpl.html ) Obviously, you should make ...


14

IANAL/TINLA: Proceed at your own risk. Yes. According to the GPL FAQ, it states here two things: I would like to release a program I wrote under the GNU GPL, but I would like to use the same code in nonfree programs. To release a nonfree program is always ethically tainted, but legally there is no obstacle to your doing this. If you are the copyright ...


13

This question was already asked on Stackoverflow in 2008 (but closed as off-topic there). This is a copy of the answer by Will M: Here is a short list of some the major differences: internationalization: they used new terminology, rather than using language tied to US legal concepts patents: they specifically address patents (including the ...


13

Adding a requirement to notify you when a fork is being made renders a license non-free. The reasoning behind this is that the requirement discriminates against people that, for whatever reason, are not able to send the required notification (for example, because their government doesn't allow free communication with foreigners). If being notified is not a ...


12

Yes you can. One example: the source code for the video game Doom 3 is released as GPL, but this release does not include the game data, which is still covered by the game's original release EULA. The answer is obvious when you realise there's a misconception that seems to be quite common: if you are the copyright holder, you can license in whatever way ...


12

The creators of GPL recommend licensing software under "version X of the License, or (at your option) any later version". If the GPLv2 licensed code has been licensed as per those instructions, then GPLv2 code is license compatible with GPLv3 code. However some projects (including the Linux kernel) do not want the FSF to be able to add/remove arbitrary ...


12

CPOL is not an open source license according to the OSI definition. It has a clause which does not allow it to be used for any purpose as mandated by the GPL or MIT license: You agree not to use the Work for illegal, immoral or improper purposes, or on pages containing illegal, immoral or improper material. Neither the GPL or the MIT license force the ...


12

It depends on the license, and also somewhat on the country. For the BSD and MIT licenses, this is a friendly yes. Your "derivative work" contains a separate copyright interest from the original and those licenses did not place any requirements on your copyright interest. These are called non-copyleft licenses. They basically say "to use this software, you ...


12

Am I right assuming that the AGPL and GPLv3 are compatible? Yes, you can combine them, with the combination effectively being governed by the AGPL v3 license: GPL v3 section 13. Use with the GNU Affero General Public License. Notwithstanding any other provision of this License, you have permission to link or combine any covered work with a work licensed ...


12

Not all changes are of sufficient novelty to constitute something copyrightable, whether they are additions or deletions. For a simple example, consider any old out of copyright song or hymn of five verses. I could make an 'arrangement' of only the first, second, and fifth verses, but this should not be considered novel enough to be copyrightable. So in ...


11

"Compatible" in this case means that you can satisfy the terms of both licenses. So the only general approach is to read the licences, understand your obligations under all of them, and then determine if you can satisfy all of them. For some common licenses, other people have already done that work. For example, the Free Software Foundation maintains a page ...


11

Maybe. Yes, you have to comply with the terms of the host application's license. However, a copyleft platform can choose to go either way. Some copyleft applications have a specific licensing exemption for plugins; in other cases, the technical architecture does not result in a derived work and thus an obligation. Consider a plugin architecture where a ...


11

(Here's my best guess. This is obviously a very hairy problem to work through, and I've tried my best to reduce the problem down to basic principles. However, I may gotten some of those basic principles incorrect. It should go without saying that this is not legal advice.) The Apache License 2.0 (APL) is incompatible with the GPLv2 simply because of the ...


11

Because adding that phrase turns the license into a viral copyleft license not unlike the GPL. When you add that phrase, you could just as well use the GPL. Those who propose the BSD over the GPL usually do so because they intentionally want to avoid the viral nature of the GPL and instead want their work to be usable by anyone under any license. The ...


11

Generally, the question of whether artwork forms a combined work with software that displays has been addressed in What do I need to share if I include CC-BY-SA artwork in my software?. If your art does not make a derivative work with your code, it's okay if the licenses are not compatible (but it's not completely clear under what circumstances code and art ...


11

The GPL does not normally require licence holders to put any special acknowledgments in their advertising material. GPLv3 s7 says that any of six additional restrictions may be added to the normal requirements of the GPL, and none of these relate to advertising material. It then goes on: All other non-permissive additional terms are considered “further ...


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