Well, but using your needs as the defining criteria for freedom is not particularly universal, is it? If a customer of mine requires that I provide them with th

Well, but using your needs as the defining criteria for freedom is not particularly universal, is it? If a customer of mine requires that I provide them with the ability to use and modify the system I build for them in any way they want, proprietary licenses are quite "tyrannical" (though I wouldn't really use that word), whereas GPL gives me the freedom to do what I want/need to do. Which also seems to highlight a possible confusion on your part, that somehow "paid for software" is the opposite of "GPL software". When I sell software, customers tend to want to be able to modify it, or to have the ability to have others implement modifications for them. And that works both with proprietary code as well as with GPLed code: It's no problem at all to sell code under a proprietary license that allows modifications for own use, but it's also no problem at all to sell code under the GPL, which also allows modifications, and at the same time allows me to build on GPLed code. Also, I don't think terms such as "GPL developer" make much sense. There just is code out there that you can use under different licenses, some of which are incompatible, and for a given project, you have to take care to select components that are compatible technically as well as legally, both between them and with the requirements of the project--and in particular, there isn't really anything all _that_ special about the GPL, as you cannot include proprietary code in a project when the license is not compatible with the customer's requirements either.