[cc-licenses] derivatives and source

P. J. McDermott pjm at nac.net
Fri Apr 6 17:23:18 EDT 2012

Hi Chris and all,

On 04/06/2012 03:29 PM, Christopher Allan Webber wrote:
> Hi Adam,
> I agree that in many ways source requirements in CC licenses would be
> great (at least in CC BY-SA).  However, I think it's also very complex,
> and thus unlikely to be implementable in 4.0, or maybe really ever
> appropriate in the legalcode of CC licenses.
> In software we have a clear definition for what is and isn't source
> code, and modifiability of software isn't really possible without
> source.  It's not as true with content, which is more of a gradient.

My rule of thumb regarding computer programs is that whatever one edits
is what one should release.  For a program written in assembly, one
would release the assembly source code.  For a program written in C, one
would release the C source code, not assembly source generated by a
compiler.  And to comply with the GNU GPL when distributing a work that
is difficult to build and/or install, one could simply describe what
he/she has done while using it.

Though I agree that the line is much more fuzzy regarding other works, I
feel that a similar rule could be applied.  Whatever one edits – be it
an image source file, a generated PNG image, video project files, a
rendered video, etc. – is what one should release.

> Your example of open textbooks is a good example of when not providing
> the "source" files is problematic.  However, I can't imagine ways to
> make all the following situations equal:
>  - So, the Blender Foundation releases Elephants Dream, and let's assume
>    it's under a CC licenses that does include a source requirement.
>    They do release all the source files.
>    - Someone makes a remix from the .blend files.  Are they obligated to
>      release the source files?

I would think they'd have to release their modified Blender source
files, yes.

>    - Someone makes a remix from the fully rendered film, a music video
>      or something.  In this case, they never even touched the original
>      .blend files at all, may have not even encountered them.  Are they
>      obligated to release gigabytes of source materials that they never
>      even touched in making their remix?

I think they should only have to release the file(s) with which they've
worked – in this case the rendered video or video project file(s).

>  - If I release a PNG, should I have to release my accompanying GIMP or
>    Photoshop files?  Those are the optimal verisons, but what if I
>    didn't keep them?  What also if someone makes a remix... do they also
>    have to distribute my original .xcf files?

If you modified a simple PNG file directly without saving any source
(e.g. XCF) files, then I'd say that's all you should have to release.
If you worked in GIMP with an XCF file and generated a PNG file at the
end, I'd say you should release the XCF file.

> I agree that it's unfortunate that we can have something where someone
> can claim to be an open publshing org and etc and actually not release
> things in a way that's actually easy for people to make derivatives
> from.  But as far as I can tell it's simply too hard to draft legalcode
> that's not incredibly hard to comply with for many cases of users, or
> which ends up being so vague that it ends up being basically useless or
> completely ignored.
> Thoughts?
>  - Chris

I'm not sure how one would effectively codify this rule in a copyright
license, but it would be nice to at least try.

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