License Compatibility: CC-BY-NC 3.0 with GPL2 (for Wordpress)?

Question

I'm trying to figure out if I can use code licensed under Creative Commons Attribution-NonCommercial 3.0 (CC-BY-NC 3.0) in a Wordpress plugin (which must be released under GPL). I think the answer is "no," based on here (https://www.gnu.org/licenses/license-list.en.html#CC-BY-NC), but I find the whole licensing mess to be just incomprehensible.

Basically, I already have a plugin that uses Fancybox (http://fancybox.net/). Prior to v2.0 this was licensed under GPL; unfortunately, the author decided to release v2.0+ under CC-BY-NC (http://fancyapps.com/fancybox/#license). 1.x is now extremely outdated and is having some problems with newer releases of WP.

So what I'm trying to figure out is, can I update the copy of Fancybox that I'm bundling with my plugin to 2.0? I think the answer is "no," because the author changed its license to CC-BY-NC. But I just want to make sure, before I start spinning my wheels and looking for a totally new solution...

Answer 1

CC-BY-NC is not a free or open source license, because it lacks one fundamental freedom: to use the work for any purpose (See the OSI Open Source Definition under “No Discrimination Against Fields of Endeavor” and the FSF Free Software Definition). The restriction to only use the work for non-commertial purposes is incompatible with free software. Also, the CC licenses aren't really suited for licensing source code, and even the non-NC variants (e.g. CC-BY-SA) might be incompatible with the GPL.

So, you're out of luck. Of course, the original Fancybox will still be GPL-licensed, as are any third-party modifications – only the original author can re-license their work. You could therefore try to fix the issues yourself, or look around for a fork someone else started.