[cc-licenses] Share-alike != Copyleft ?
gmaxwell at gmail.com
Wed Feb 14 21:29:34 EST 2007
On 2/12/07, Roger Chrisman <roger at rogerchrisman.com> wrote:
> Gregory Maxwell wrote:
> > I'm looking for a little clarification: Is share-alike actually the
> > same as copyleft?
> Devil's in the details
> Copyleft has lesser and stronger licenses associated with it, e.g. LGPL
> and PGL.
> Is CC-by-sa a lesser copyleft license rather than a stronger copyleft
> license? I don't know.
The notion of "weak copyleft" isn't at all new to me, but I and a
number of other people consider it to be a pretty ridiculous notion.
A totally uncited Wikipedia article is seldom a great reference. :)
The fundamental purpose of a copyleft license as opposed to
non-copyleft licenses is to encourage the expansion of the public pool
of free materials. They achieve this by using reciprocal licensing to
allow the use of a copylefted work in derived works if and only if
those works are as free as the copylefted work.
It's pretty straightforward to see how this applies to images.
Someone is writing an article on bassoons. They need a high resolution
image of a bassoon to illustrate their article. They can pay several
hundred dollars for one from Getty Images, or... they can use a
copyleft one but they have to make their article free content if they
If they are just writing the article for their students, or otherwise
have a motivation or business model which does not preclude freely
licensing their works, then making their work free would obviously be
the less costly solution.
In these cases content creators would use a free license for their
work when otherwise they might have stayed "all rights reserved" or
selected the trendy Creative Commons "cc-by-nc-nd-only-in-africa"
license of the week.
By this process copyleft works create an incentive for producers to
produce free works. This incentive is material and lasting, unlike
depending on license branding and trendiness to encourage people to
use a particular license.
So to whatever extent a "weak copyleft" exists, it simply isn't
interesting as a form of copyleft: it won't have the property of
leveraging the pool of free works to encourage new works to be freely
licensed as well. I think this is especially relevant for images,
because copylefted images can be an attractive alternative to the
expensive stock photography which is so widely used. (And an
attractive alternative to the 'creative commons' content which is,
more often than not, under a license which discriminates against
commercial use except, apparently, the exploitation of user-created
content by Web 2.0 darlings, but that's another rant...)
I would also argue that a "weak copyleft" license is a bad deal all
around... Copyleft imposes additional annoying terms on downstream
users. We can justify doing this because copyleft increases the pool
of free works, benefiting everyone. A "weak copyleft" would not have
this property.. so the additional terms are an unneeded friction which
do not benefit the copyright holder or the public.
So... in light of your reply, please allow me to restate my question
in a way which can not be confused:
"Are the share-alike Creative Commons licenses intended to increase
the pool of similarly licensed works by utilizing the pool of
share-alike work as an incentive for the creators of new content to
release their work under a free license?"
This is not a hard question... It's one that I'm sure the Free
Software Foundation would have no problem answering for any of their
own licenses. Nor would I expect it to be a problem for most other
groups who have produced publicly available licenses.
I think this is a question that the Creative Commons side must answer
before anyone who currently distributes a copyleft license can
consider the sort of bidirectional compatibility that the draft
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