I'm looking for an open source license which grants me additional privileges.
- Anyone can freely modify, fork, use the code, as long as they make their source changes publicly available. They can use it in other open source projects, but not in closed-source projects. (similar to, say, GPL v3, with strong emphasis on contributing back)
- Only I and entities I specifically designate can use the code as part of a closed-source application. I am also exempt from the duty to publish the source code changes. (exemption from GPL duties).
- In return for my work, I do want the freedom to benefit from other's contributions (by using the project in my closed-source work), even if they fork the code.
I'm not trying to forbid the commercial use, just to allow myself more flexibility to use the code, while still contributing to open source. I don't want to burn myself by being legally forbidden from using the libraries I wrote in my commercial projects.
Large companies use such dual licenses to maintain an open source project, while also selling the premium version.
Which licenses of this type are available? What caveats or obstacles exist?
Is there any read-made license for this situation? Consulting lawyers is not an acceptable option at this point in development.