Is it possible for someone to change an open sourced program to a commercial program? [closed]

Question

Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.

---

Want to improve this question? Update the question so it's on-topic for Stack Overflow.

Closed 6 years ago.

Improve this question

1- If there is a Version 1 of a software under GPL license and a version 2 under a commercial license, can other developers continue working on Version 1 of the software and have their own version of the program?

2- Alternatively, is it possible for the original author to change the license of a currently open-source software to a commercial software and thus preventing others from making free versions of it? And are new programs created from when it was open-source now against the law?

Answer 1

Answers:

1. First question, true, if there's a gpl version you can fork and make your own version, but you cannot close-sourced your version, if you publish it, it must be under a GPL compatible licence.

2. Second question, true, the author can change the licence of his open source program, but only if he has the copyright to all the code in the project, that is to say, the project should not have code or patches contributed by other developers, in this case the original author has to ask those developers if they are ok with changing the licence, they can oppose and the licence could not be changed. This scenario can be circumvented if before accepting code or patches from other developers you made them sign copyright attribution agreement, which means they hand over the copyright of their contributions (code/patches) to the original author, so in this case he maintains full copyright over all the code and so he could change the licence in future without consulting anyone.

3. About your third question:

   And are new programs created from when it was open-source now against the law?

   No they aren't, if version 1.2 was last version open sourced, and version 1.3 is now closed-source, anyone could take version 1.2 and further develop and make new programs from it, but again the end result must be open sourced if you publish it (or GPL compatible for the matter).

Answer 2

1- If there is a Version 1 of a software under GPL license and a version 2 under a commercial license, can other developers continue working on Version 1 of the software and have their own version of the program?

Yes. Their own versions must be distributed under the GPL, too, of course.

2- Alternatively, is it possible for the original author to change the license of a currently open-source software to a commercial software and thus preventing others from making free versions of it? And are new programs created from when it was open-source now against the law?

Once someone receives a copy of the program under a given license, you can't change the license from under their feet. So, if a program was once released under GPL, anyone who downloaded the GPL version has the perpetual freedom to use and modify their copy, and distribute their modifications, under the terms of the GPL.

What you might be able to do is change the license of your GPL program to a different license (for example, a "commercial" (i.e. proprietary) license), and then people who download the program from you from that point on are bound by the new license (however, keep in mind that people who had downloaded the program back when it was GPL are still free to distribute it to other under GPL terms, you can't take that away). Whether you can do this depends on whether you're the sole copyright owner of the program. If you are, you are free to re-license it how you want. If you're not (for example, because you accepted contributions from others without having them assign their copyright to those contributions to you), then you need permission from all the other copyright owners before you can re-license.

Answer 3

1. In general, this depends on the text of the license, but for the GPL specifically, if some version of a program was release as GPL, the general consensus of many who have explored this scenerio is that it can't be retroactively revoked. So yes, other developers could continue working on the GPL version and make their own versions of it, as long as they kept to the terms of the license it was released under (i.e. in this case released their own code and changes under the GPL as well). Obviously there are nitty-gritty details. Read the license text carefully.

2. The original author can relicense anything they have written all they want. That doesn't necessarily revoke the original license grant, and as stated above, the general consensus is that this is not possible to do for the GPL specifically. For other licenses, it may differ based on what was in the text of the original license grant. So for GPL software, no, the original author can't retroactively revoke it's GPL-ness or prevent others from continuing to make new versions of it.

All of this of course is ignoring trademarks, gory details, etc. Obviously you'll want to do your own research and make your own decisions before doing something that could be legally questionable.

Answer 4

Open source software is compatible with being sold commercially. The GPL doesn't prohibit programs from being sold for money.

To your questions:

1. Yes. You can work on GPL versions of a program.

2. No. You can't revoke a program's GPL licence.