Marijn is the creator of a number of pieces of software, including [[CodeMirror]] and [[ProseMirror]], for which he has a number of different sponsors. He keeps his code under an [[MIT License]]. His funding page says this:
Building and maintaining software is skilled, specialized work. I prefer to allow the whole world to use my software, but I do need some kind of income.
Thus, I ask people and companies who use my software to make profit to fund the production of that software. This is a social expectation, not a legal requirement.
Above, where “prefer” is linked, he has a blog post that explains in more detail what this social expectation is:
But along with this legal licensing situation, I am going to emphasize, in the docs, the license file, and the communication surrounding the project, that free-loading is not socially acceptable. Along with this, I will provide convenient mechanisms to donate. The code of financial conduct would be something like this:
- If you are a non-commercial user, don’t worry about it.
- If I fix a bug you reported or add a feature you wanted and you have the financial means, a one-time tip is much appreciated. Even if this is unlikely to add up to serious money, it takes the one-sidedness out of the process of responding to user requests.
- If you are extracting value from your use of my software, set up a proportional monthly donation.