Subject talk:CK-12 books

Licensing Terms?
The CK-12 web site now provides their books under a non-commercial CC-BY-NC-SA license. I have read a claim that they previously used the CC-BY-SA license and that our books are derived from the earlier materials, but do we have the supporting evidence for this claim? Perhaps we should be collecting together our copies of the older books and storing them somewhere safe. Recent Runes (talk) 19:35, 1 December 2010 (UTC)


 * The "wayback machine" has the site archived from July 2008. On this version the license is described as "share alike" and linked to the Creative Commons Attribution-ShareAlike 3.0 US license. On the 31 July 2008 version the license has changed to Attribution -Share Alike 3.0 Unported. It isn't proof, but it would be reasonable to assume that if our books were begun before 31 July 2008 then they used content under an acceptable license. The 31 July 2008 archive is the last one captured, so I can't see when the license changed to a non-commercial one. QU  TalkQu 20:29, 1 December 2010 (UTC)


 * Actually, it looks like Adrignola has already uploaded useable PDF files to Commons for the books we have here at the moment, so the only issue could be to ensure that no more new material is taken from the CK-12 web site. Recent Runes (talk) 21:17, 1 December 2010 (UTC)


 * Indeed, as you can see the CC-BY-SA logo in those PDFs. It was around the middle of 2010 that they changed the license.  They also went back through and regenerated all their PDFs with the NC logo in them.  It was a bit like pulling a rug out and made me very disappointed, but fortunately I had the foresight to download them all to work from.  Some of them I had to break into pieces because they were larger than the 100MB upload limit, but doing so allowed me to link to PDFs at Commons rather than at the CK-12 site.  I'm sure they regret the fact that they can't change licenses retroactively on already-released material, but that's our gain. – Adrignola talk 00:27, 2 December 2010 (UTC)