My personal idea is that you shouldn't open source anything you plan to make money from. Technologies that you build along the way (like React out of Facebook a

My personal idea is that you shouldn't open source anything you plan to make money from. Technologies that you build along the way (like React out of Facebook and a million other examples) are good candidates for open source. Open source db software is suitable for these dual licenses - using it is free, but if you are going to sell products and services that are repackaged versions of the tool, you should pay the creator (like mysql).