Something to read about selling exceptions to the GNU GPL?

Actually something very poorly could find about dual-licensed under GNU GPL + commercial.
Does anyone have links to something to read on the subject?

Interestno General issues and application examples.
Courts on this subject (if indeed they were somewhere) interestingly, too, probably would
July 2nd 19 at 17:24
2 answers
July 2nd 19 at 17:26
Solution
> dual licensing under GPLv3 + commercial

GNU GPL + proprietary, presumably, you mean. But in General this practice is quite clear title — selling exceptions to copyleft. "Dual licensing" to call it imprudent though, because different licenses may be (and likely is) much more two somebody, you may sell urgent non-free license, someone indefinite, someone with a limit on the number of cars, some without, and so on.

Also, this practice is not limited to actual third version of the GNU GPL. And surprisingly, not limited even by the strong copyleft of the GNU GPL or GNU Affero GPL; some comrades manage to sell exceptions to weak copyleft GNU *Lesser* GPL, examples: Qt, CppCMS.

What is there to read, I don't even know — practice guileless as a stump. The only thing we must attend to is agreements with future free co-authors (contributor agreements) if they want to appear. Because you to sell exclusion for the benefit of his own pocket, obviously, should have the right to do that, ideally (for you) means to be the sole owner of the program, then sponsors will need to request the assignment of author's property rights (copyright assignment). A good example of such agreements is traditionally considered ownCloud'ovsky.

In addition to the three mentioned examples from different areas: MySQL (database), Ghostscript (library to support PS and PDF), ChibiOS (RTOs).

In short, if you have specific questions, it would be better to ask them.
Thanks for the good answer!

Yes, you read that right - opensis + nonfree(perpetual, subscription or other does not matter).

Surprisingly vacillation on the links Wikipedia gave similar thoughts - two licenses and, optionally, the type of contributor agreement.

But vseravno - the practical side holistically is not described anywhere. In fact, it is necessary to consider (under the microscope) of individual projects using dual-licensing. And write yourself guide\policy. - astrid_Sawayn commented on July 2nd 19 at 17:29
Here's another source that mark only AGPL. This is really enough?
And closed license (or the opportunity) does not need to be the same place in the header specified?
It's quite prakticheki question. - astrid_Sawayn commented on July 2nd 19 at 17:32
:> And a restricted license is not supposed to be there in the header specified?

You contradictions in the wording of the question don't see? :-) How can she be so specified if it is, as you put it, "closed", i.e. *individual*?

If you ask if your a non-free license to make as open, it is possible, of course. And perhaps even reasonable. - arturo_Armstrong43 commented on July 2nd 19 at 17:35
:> Thanks for the good answer!

You're welcome.

> two licenses and, optionally, the type of contributor agreement

Why optional?

> Actually it is necessary to consider (under the microscope) of individual projects using dual-licensing. And write yourself guide\policy.

What "guide" or "policy"? If you are already engaged in licensing proprietary software, there is nothing new here for you, in addition to working with the sponsors that can be postponed until the first appearance of such. If not engaged — then organising nepahannoe edge — search for legal counsel, tax consultant, etc., and not read Wikipedia. :-) - arturo_Armstrong43 commented on July 2nd 19 at 17:38
: > You contradictions in the wording of the question don't see? :-) How can she be so specified if it is, as you put it, "closed", i.e. *individual*?

Have ownCloud and Mongo in the header sorrow only AGPL - I QT ``
...
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
.....``

That is why it is so? - astrid_Sawayn commented on July 2nd 19 at 17:41
:> from QT

So this is not a contract, just a comment. - arturo_Armstrong43 commented on July 2nd 19 at 17:44
July 2nd 19 at 17:28
-1. In what place there is an answer to the question? - astrid_Sawayn commented on July 2nd 19 at 17:31

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