[Commons-l] [cc-licenses] [Foundation-l] Requirements for a strong copyleft license

[Gregory Maxwell]

On Dec 3, 2007 3:32 PM, Terry Hancock <hancock at anansispaceworks.com> wrote:
> Of course, courts have in the past invalidated contracts on the basis
> that they make "unreasonable" or "unexpected" demands that were not
> understood by the party agreeing to the contract, and so invalidated
> contracts. So, there's probably *some* limit on copyleft. But I'm
> reasonably certain that "what could be considered a derivative under
> copyright law" is not it.

Without delving into the weeds of licenses vs contracts ... In the
absence of a license you have no right to distribute the covered work
at all.    It is the all-rights-reserved default nature of copyright
that largely gives copyleft its teeth.

In the US at least, with the enormous dependence  the software
industry has on EULAs, you can bet that any court verdict which allows
terms to be removed would be quickly 'solved' with the introduction of
new law from the lobbied^Wlegislative branch of government.

[snip]
> While I do find there are times when publishing free-licensed images
> alongside non-free text is desirable, this is not my main concern. For
> such functionality, the CC-By license is nearly as good as CC-By-SA
> anyway, so I agree with that point.

This has been my position.  I've not yet figured out the gaps which
are preventing agreement from some others.

> For me, the main fear is a collision between various copyleft
> free-licenses, who all have essentially the same intent, but necessarily
> have different implementations, because they are designed for different
> creative domains.
[snip]
> So, we want to keep copyleft from crossing certain domain barriers and
> binding works in unreasonably restrictive ways. We risk making the
> "commons" as difficult to navigate as the fenced-in world of
> conventional copyright.
[snip]

The *ideal*, I think, is that copylefed works should be usable as
components in copylefted works, as well as in works which are licensed
in a manner which is strictly less restrictive (such as X11 licensed,
or CC-By) which results in the whole being effectively copylefted,
even if some of the parts are not when used separately.

Fully achieving that ideal may well be impossible because, as you
pointed out .. different types of work differ.   What might be an
acceptable restriction on a piece of pure art might be considered an
unacceptable restriction from the perspective of purely functional
works (like we sometimes find in software).

That said, It would be useful if we could say with confidence we at
least know what the ideal is...