CC's own FAQ addresses the reasons, which I find satisfactory, so I'm just going to reproduce it here and expand on the key points:
Unlike software-specific licenses, CC licenses do not contain specific terms about the distribution of source code, which is often important to ensuring the free reuse and modifiability of software. Many software licenses also ...
It depends. For Stack Exchange: yes.
When you write something, you own the copyright, and have the right to do whatever you want with it (from a copyright perspective at least).
When you post something to some site, you usually give a license to use that material on that site, through the terms and services, or you transfer the copyright to them.
If the ...
Yes indeed, as the sole author (copyright owner) of a library, you are not bound by the terms you choose to license it to the general public.
Thus you can use it in your own proprietary programs.
This is also why you can dual-license, re-license the work or sell commercial licenses.
Now, you must be very careful that you really are the sole copyright ...
CC-BY-SA is a technically perfect open source license.
CC-BY-SA's use is discouraged because of the "license proliferation" problem.
Going into more detail on the first point, first we need to know what it means to be an "open source" license. OSI has a great definition of what it means to be open: http://opensource.org/osd
Lets go through each ...
You're conflating features of the Stack Exchange engine, which copyright law doesn't care about, with ownership and licensing.
All user content (i.e. the posts and comments, not the user interface bits) on Stack Exchange is owned by their authors (there is no transfer of copyright — that's not even a thing in some jurisdictions; it is in the US but SE doesn'...
If you want to restrict your software to not be used for commercial purposes, it is not open source.
You can release it under multiple licenses - such as the GPL and a commercial license (where a user can choose one or the other, obviously having to pay for the latter) - but it seems from your question that you're not considering the GPL either. The GPL ...
The natural interpretation of such a license declaration is that they are dual licensing their work:
You can use and distribute it under the terms of the GPL3, which because it is a copyleft license means that your derivative work must also be licensed under the GPL3, so you must make your source code available etc.
Or, you can buy a commercial license ...
This might take a while, your question isn't a short one, and it seems to me to have a number of misconceptions in it.
I frequently create programs [...] in other script languages, such as PHP (PHP License) and Perl (Perl Artistic License, or GPL v1+)
The licences you quote are those which apply to the languages themselves. With the exception of a very ...
When you use the open source version, you can ask any 3rd party vendor you consider qualified for support. The original licensor can't prevent anyone from offering advise, and the right to fork gives 3rd parties the right to make any changes you want.
However, be aware that:
Trademark laws might make it difficult for 3rd parties to advertise their support ...
Yes and no.
You can make a claim like that, but it does not override the site policy, it adds to it. In effect, it means that your code is now dual-licensed under both the CC BY-SA and the Apache license and I can choose which of the two to apply when reusing your code.
Does this sentence just summarize what the consequences are of
licensing (to SE) my content under CC BY-SA 3.0?
Or does this sentence state that I’m licensing (to SE) my content
under a second license?
It does not just summarize the CC-BY-SA license. You are indeed dual licensing your content to Stack Exchange. By posting to a Stack Exchange site, ...
Bob can relicense it under any license he wishes.
Taking credit for Alice's work is another thing. In jurisdictions that hold up moral rights, Bob can't. The moral rights cannot be given up by Alice, so they are still intact. What consists moral rights differs a bit, but proper attribution is usually included. In jurisdictions without moral rights, ...
You can license your intellectual property under different licenses to different people. But when your license follows the definitions of open source and/or free software, the licensees have the right to relicense it under the same terms to other people. So this would not be an effective way to control distribution.
When you want to control distribution, ...
It does not lock you into a provider. You are free to hire another provider to maintain the open source version for you. So the only "lockin" is the fact that whatever you paid the first vendor is sunk, and maybe the second vendor won't be allowed access to the first vendor's modifications.
If the first vendor didn't modify the code, or if they sent their ...
You're correct in your last paragraph at least: the || symbol will mean nothing to people who have no programming knowledge.
If you know that the only people visiting your project will be programmers, that's OK, but there are still less ambiguous ways to represent it.
In fact, the simplest way may be to simply say it:
This project is dual-licensed under ...
No, the two licenses don't have to be compatible.
If you are legally allowed to dual license something, usually because you are the copyright holder, you can pick any two licenses, even if they conflict. As a matter of fact, dual licensing is usually used to get around license conflicts, that is, by offering something under two conflicting licenses. One of ...
What's the best license?
To make sure as many people can use your contributions as possible, you should license them as public domain. Anyone can then use your work with no restrictions. However, this is not possible in some jurisdictions: look up where you live and if it's not possible, use CC0 instead.
Is that enough?
Yes. You're the copyright owner, you ...
Coming from a background in open-source, your model is not that reliable.
In general, open-source licenses must comply with the open-source definition, in particular sections 5 and 6:
5. No Discrimination Against Persons or Groups
The license must not discriminate against any person or group of persons.
6. No Discrimination Against Fields of ...
This is going to be long, because changing the license from the GPL to a more permissive license is really complicated for a project that is big, old, and has many contributors.
An open-source license should not be chosen because it is popular, but because it is aligned with your goals:
Strong copyleft licenses like the GPL (and for web apps:...
Firstly, no it's not invalid at all. It's always valid to dual or multi license a product under many licenses, even completely contradictory licenses. When you dual license something the recipients get to choose which license they will accept the work under. They only choose one, so it doesn't matter if another license would give them contradictory rights.
Having read the original page (and as a side-note it would be helpful if you were to provide links in your questions), what is going on is not a licence violation, but dual licensing.
Cheerp is distributed as a Free and Open Source Software under the University of Illinois/NCSA Open Source License (core compiler) and under the GNU General Public ...
Those fonts aren't part of Firefox. They're your computer's system fonts. There's no rule that says open-source programs can't use proprietary resources that happen to be available on the system where they're installed.
Licences do not inhere in software, they attach to software (or, to be more precise, to the recipients of software) through the act of conveyance.
Which is a complex way of saying that what other licence some other person gets software under has no effect on you and the licence under which you get it. If you get libfoo under a free licence, let's say the ...
If you can spare words and it doesn't have to be language neutral, for example
You may use this work under the terms of either CC-BY-SA, or (at your option) CC-BY-NC
Your choice of CC-BY-SA or CC-BY-NC
The former is similar to what the GNU project uses in their GPL versioning to allow using the current or any later versions (http://www.gnu.org/...
The simple answer is no, it doesn't make much sense.
You've posted this work on Stack Exchange, where it's licensed under CC BY-SA. I go and copy your work, use it in something I'm doing, and release it perfectly legally under BY-SA. My use case is legal, yes?
Bob sees what I've done, and sees the attribution to you. He decides he likes your work, and he ...
Maven allows several licenses in its <licenses> block and its meaning is defined as a choice as @Tordanik explained here correctly. (This not undefined as I originally mentioned):
If multiple licenses are listed, it is assumed that the user can select any of them, not that they must accept all.
Yet, this is not something that is explicit and obvious, ...
The Maven site provides a definition in the project descriptor reference (emphasis mine):
This element describes all of the licenses for this project. Each
license is described by a license element, which is then described by
additional elements. Projects should only list the license(s) that
applies to the project and not the licenses that apply to
When software is diffused under an open-source licence I imagine that a project becomes the "intellectual property" of the community.
This is incorrect. Unless copyright has been reassigned, the content creator owns their contributions to a work. As a copyright holder, you can freely choose what rights you want to grant to other people, including different ...