Non-Commercial Licenses Are Non-Free Licenses
I have had to explain this a couple of times on various forums, so I thought it would be good to write a post about it and explain why non-commercial licenses are non-free licenses. Some examples of non-commercial licenses are CC BY-NC, CC BY-NC-SA, and CC BY-NC-ND. These are all non-free licenses.
The fact that non-commercial licenses happen to be non-free licenses appear to be counterintuitive to some. Isn't prohibiting the usage of some artefacts for commercial purpose good for free artefacts? Maybe it is. May be it is not. That is irrelevant while deciding whether a license is considered free or not. What is relevant though is whether the license satisfies the principles laid out in some of the widely followed principles of freedom in creative work. Especially in the context of software, such as for licensing artefacts related to software development and usage, we have a few widely accepted guidelines that we can refer to:
Note that when we say "free" here, we mean free as in speech, not free as in beer. Prohibiting commercial usage of some work violates these principles of software freedom mentioned in the documents referenced above:
Freedom 0 of the Free Software Definition (FSD): The freedom to run the program as you wish, for any purpose (freedom 0).
Point 6 of the Debian Free Software Guidelines (DFSG): No Discrimination Against Fields of Endeavor: The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.
Point 6 of the Open Source Definition (OSD): No Discrimination Against Fields of Endeavor: The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.
By the way, the OSD was originally derived from the DFSG. That is why the OSD looks quite similar to the DFSG.
So what does this all mean and why should you care? The non-commercial licenses are good at doing what they are meant to do, that is, prevent commercial exploitation of your work. If that is what you want, the non-commercial licenses are perfect for you. But it is worth noting that restricting non-commercial usage does come at the cost of unhindered collaboration. For example, a work licensed under CC BY-NC, CC BY-NC-SA, or CC BY-NC-ND cannot be remixed, adapted, or relicensed with work licensed under the CC BY or CC BY-SA.
If you want unhindered collaboration, CC BY is one of the most permissive licenses available from Creative Commons. There is also CC0 which gets as close to public domain as possible. CC BY-SA is another good option if you want to ensure that one cannot remix your work into some proprietary work and redistribute it. But note that even CC BY-SA requires that you do not impose any additional restrictions to the license terms. That is, even CC BY-SA allows commercial usage and is incompatible with any non-commercial license.