[squires]

I think it might be an interesting approach to run a kickstarter-style campaign for each major software release, and once the goal is reached, release the software with a normal open source license. Nothing would stop other developers from forking the software, but if the author was providing enough value, I believe people would contribute.

[qznc]

Example: Krita https://krita.org/item/weve-done-it/