I recently ran across two software products which claim and use Creative Commons licensing (one of them, RGraph: http://www.rgraph.net/). These products are used to create visualizations (graphs), which could be argued to be derivative products of the software used to create them. So while the code product may be CC, the question becomes, is the data as it embedded in the graphs then also CC’d and are the Images the graphs create then also CC’d as derivative products? It seems that the world would quickly become confusing, if a share-alike license is used.
I ended up writing to Creative Commons, and asked few questions, I felt it was worth the question as my previous understanding was the use of CC was that it was for non-code based works, but then where does “code” actually stop? At some level a text based, book like, PDF is both code and a book… It has also my understanding that CC licenses did/do not cover data sets and that is why the ODbL was formed (Check out this post by the CC for more on CC and Databases). It seems that for visualizations, especially dynamic interactive ones, that GPL v.s. CC v.s. ODbL each have something to say.
Fortunately, the creative commons people gave a great reply and pointed me to their website.
Can I apply a Creative Commons license to software?
We do not recommend it. Creative Commons licenses should not be used for software. We strongly encourage you to use one of the very good software licenses which are already available. We recommend considering licenses made available by the Free Software Foundation or listed at the Open Source Initiative. Unlike our licenses, which do not make mention of source or object code, these existing licenses were designed specifically for use with software. Furthermore, our licenses are not compatible with the GPL, the most frequently used free software license.