For a popular program licensed under GPL3, a system of plugins exists. The program and the plugins are closely interoperable and exchange large structures of data, so the plugins will necessarily be also under GPL3.
Situation
Someone is willing to pay me to develop a certain plugin because someone else is paying her for the development.
I will deliver the code to my client and in turn she to her client, and both my client and the final client are aware of the plugin being GPL3.
Although the license says that anybody requiring the source code, the source will be delivered, I think they are not planning to publish it initially (although they conform to give it if someone requires it).
Monetization
They are willing to pay me for developing this plugin because they plan some kind of monetization of this plugin (I'm not clear on how, though). But my client is a company and the client of my client also a commercial company.
I know I will be "the author" by the fact of being me the one that thinks, models, architectures and finally codes.
But... Question
Do they as payers retain any special right further than "getting it done"?
Do I retain the ability to "publish it to github"? Or as I'm being paid, the decission to publish is theirs and I can't do unless I request permission from them?
I'm not having any intention to break their business up. If they pay me, the most natural is I don't publish it. I just deliver the code to them and forget.
But maybe after some time, for any reason I feel it'd be valuable for the society to have it in github.
I wonder if
- I can just publish it, or
- I have to require permissions from them, or
- I can publish but I have to mention them as holders of any kind of right for the mere fact of having paid for the plugin to exist.
Pointers to specific paragraphs of the supporting documentation will be appreciated.