I did some research about the popular open source software licenses and none of them explicitly solve a particular point I'd like to have:

  • I don't mind at all to allow for free use and distribution of the source, nor do

  • I want to force people to contribute with their mods nor anything containing their IP.

The following 2 things I'd like to have:

  • A notice which states clearly that I develop the original source(the apache license has this in the form of a NOTICE file as far as I know).

  • If a person ends up distributing a commercial or open source project based partially or entirely on mine, he/she lets me know about the existence of such product/project, nothing more, nothing less.

Do you happen to know if something that specific happens to exist out there or maybe I can just make a small mod to a popular license?

  • 1
    Have you considered Open Source Stack Exchange?
    – HDE 226868
    Commented Sep 5, 2015 at 23:25
  • 2
    As a software developer I'd caution you about coming up with restrictions like this. Your library better be pretty spectacular if you're going to start enforcing uncommon things like this. Take for example openSSL. I have to show Eric Young's name any time I advertise my product. That's uncommon and pushing it for me, but since I'm not a world class cryptographer and can't roll my own, I'm willing to comply. However that still hasn't kept me from investigating using alternative libraries.
    – user900
    Commented Sep 5, 2015 at 23:27
  • Most licenses already do the former, but I have never seen one that does the later?
    – user2425
    Commented Sep 8, 2015 at 10:10
  • 1
    This is an absolutely terrible idea. When you change email addresses, or sell the copyright and then get hit by a bus, it suddenly becomes impossible for people to comply with the license. Your software, which was previously free, is no longer free.
    – user3392
    Commented Nov 10, 2015 at 0:31
  • Commercial is not the opposite of Open Source. E.G. the GNU licence and many others are Free Software, Open Source, and commercial licences. ““Free software” does not mean “noncommercial”. A free program must be available for commercial use” Commented Jan 9, 2016 at 11:16

2 Answers 2


There's a couple open source licenses that I currently think of, that resemble your requirements. The Reciprocal Public License, and the General Public License.

These licenses have a bit of a "giving-back" requirement, in other words, they've got a copyleft clause. Anyone who uses software licensed under the RPL or the GPL need to provide the source code back to their community. However, the two licenses differ, albeit minimally.

The RPL forces you to distribute any modification that you make, even if you do not deploy it publicly. The GPL forces you to distribute any modification that you make, when you deploy it publicly. Distribution is defined as making the source code available.

These are just about the closest you can get. These licenses can't force them to notify you of any changes, but they do force them to make available any changes that they make. If they host their code on GitHub or something like that, it should be relatively easy to search for such projects.

  • 1
    The free-software-foundation that wrote the GPL state that, software that has a licence that requires you to tell the original author (or any one else) of changes, is not free-software. The GPL does not ask you to tell the original author. In addition, if you modify GPL code, you do not have to give anyone a copy, but if you do distribute a copy then, you must distribute it under the same licence, and make your source code available. Yes you explain this in paragraph 3 and 4, but paragraph 1 and 2 suggests otherwise. Commented Feb 1, 2016 at 20:49
  • @richard Yes, but they do require you to make that available. Which is a fairly good compromise.
    – Zizouz212
    Commented Feb 1, 2016 at 20:51
  • I would go with GPL, as what is asked for is a legal mine-field. Many including my self would not use software with a clause that demands redistribution. Commented Feb 1, 2016 at 20:54
  • @richard Yes, definitely. The idea of having a source license like that would simply be dreadful. And the GPL is already bad as it is.
    – Zizouz212
    Commented Feb 1, 2016 at 20:55
  • If you tell us what you do not like about GPL, them may be we can help. Commented Feb 15, 2016 at 23:16

Clause one is fine, but clause two “If a person ends up distributing a commercial or open source project based partially or entirely on mine, he/she lets me know about the existence of such product/project, nothing more, nothing less.” is not:

Putting this clause in will stop the software being Free Software or Open Source, but with a little modification to conditions it can be both.

from https://opensource.org/osd-annotated

The license may restrict source-code from being distributed in modified form only if the license allows the distribution of "patch files" with the source code for the purpose of modifying the program at build time. The license must explicitly permit distribution of software built from modified source code. The license may require derived works to carry a different name or version number from the original software.

Free Software definition says, you can not restrict modification, but can in a limited way restrict distribution (make them change name, informs previous developers) http://www.gnu.org/philosophy/free-sw.en.html

Whether a change constitutes an improvement is a subjective matter. If your right to modify a program is limited, in substance, to changes that someone else considers an improvement, that program is not free.

However, rules about how to package a modified version are acceptable, if they don't substantively limit your freedom to release modified versions, or your freedom to make and use modified versions privately. Thus, it is acceptable for the license to require that you change the name of the modified version, remove a logo, or identify your modifications as yours. As long as these requirements are not so burdensome that they effectively hamper you from releasing your changes, they are acceptable; you're already making other changes to the program, so you won't have trouble making a few more.

Rules that “if you make your version available in this way, you must make it available in that way also” can be acceptable too, on the same condition. An example of such an acceptable rule is one saying that if you have distributed a modified version and a previous developer asks for a copy of it, you must send one. (Note that such a rule still leaves you the choice of whether to distribute your version at all.) Rules that require release of source code to the users for versions that you put into public use are also acceptable.

Irrevocable, even on death (how do we contact you if you are dead, and 1000 other circumstances, that I can not thing of all of them).

In order for these freedoms to be real, they must be permanent and irrevocable as long as you do nothing wrong; if the developer of the software has the power to revoke the license, or retroactively add restrictions to its terms, without your doing anything wrong to give cause, the software is not free.

Hope you find a licence you like, do not make up your own (we have enough, and they are hard to do well). One of the best things to do, is make it easy for them. Put the project somewhere like github (though I don't like git: it is too difficult for me). Then people will contribute because it is easy to.

I remember part of the rational of the Free Software rules is: imagine some people being persecuted my a corrupt government. They are using you software to fight for their freedom, and need to change it. If they transmit there changes to you, they will be arrested and shot.


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