The legal page has two references to "the Creative Commons Attribution Share Alike license," and both of them link to cc-by-sa version 3.0.

However, the bottom of every page links to version 2.5. So does the blog.

EDIT: There are some noteworthy differences between the two. 3.0 has a no endorsements clause, and it introduces the concept of a "Creative Commons Compatible License", a third-party license approved by CC as "essentially equivalent" (none are approved yet). The generic license was renamed to be the US license, and they made a new "unported" license (linked above) to fulfill a similar role. 3.0 is also approved as free by Debian. CC has a article and blog entry with more info.

  • Good catch, not sure what the differences are between 2.5 and 3.0. Summary looks the same. Aug 22, 2010 at 15:01
  • So, uh, here's a thing. The edited legal page says "the Creative Commons Attribution Share Alike license" with no version. It happens to link to the version 2.5 license, but does not explicitly say so. This creates ambiguity.
    – mattdm
    Feb 2, 2011 at 6:51
  • @matt the link is explicit and this should suffice Apr 8, 2011 at 23:43
  • @Jeff — you're the one with the legal team, so I'll take your word for it. :)
    – mattdm
    Apr 10, 2011 at 11:51

1 Answer 1


Good catch, I updated it to refer to 2.5 for consistency if nothing else. Not sure if the minor tweaks of 3.0 over 2.5 are particularly relevant to us, or not.

edit: as of yesterday, we re-licensed under cc-by-sa-3.0.

  • 4
    There's an important way in which they are relevant: content with newer versions of the license isn't backwards-compatible and so cannot be incorporated into stack exchange questions or answers. I know we want new, original content, but sometimes it's helpful to be able to incorporate other CC-licensed material.
    – mattdm
    Jan 14, 2011 at 4:23
  • @matt we just re-licensed under 3.0 Apr 8, 2011 at 23:42
  • outstanding issue: meta.stackexchange.com/questions/214633
    – lofidevops
    Sep 9, 2014 at 10:25

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .