I'm about to create a new open-source project and I'm not sure about the licensing method I should choose.
Here is what I know:
The project will be built on the basis of an already existing open source. I will fork from the original project and will build a community around a new project that has a code base from the original project.
In case the new project becomes successful, I will want to, one day, fork to an extended version of it which I will earn from. I want the non-free version to be non open-source.
For now, I have 2 main projects that I can use as my base project. One has a GPL license and the second has MIT license. I'm wondering what would better suit my needs. Also I'm wondering which license should I use for my open-source in order to, maybe, someday fork for a paid version which will not be open-sourced?