Please add info on non GPL copyleft licenses

[Richard Fontana]

On Fri, Nov 14, 2014 at 05:29:58PM -0500, Bradley M. Kuhn wrote:
> Teg,
> 
> Teg Skywalker wrote:
> > Most of your content focuses on the GPL licences, but are you going to add
> > other copyleft licenses like the Mozilla Public License to your docs? It
> > may be good to have so people can compare the copyleft licenses outside the
> > GPL ecosystem with the GPL ones. Definitely something to consider.
> 
> I absolutely agree.  Did you happen to happen to see the announcement of
> copyleft.org on FSF's and Conservancy's site:
>    https://sfconservancy.org/news/2014/nov/07/copyleft-org/
>    http://www.fsf.org/news/software-freedom-conservancy-and-free-software-foundation-announce-copyleft.org
> 
> To quote from it:
> 
>    copyleft.org welcomes all contributors. The editors have already
>    incorporated other freely licensed documents about GPL and compliance with
>    copyleft licenses -- thus providing a central location for all such
>    works. Furthermore, the project continues to recruit contributors who have
>    knowledge about other copyleft licenses besides FSF's GPL family of
>    licenses.
> 
> We've gotten a number of volunteers, Mike Linksvayer being one who is
> mentioned in the press release itself, willing to contribute on CC BY SA.
> We'd definitely welcome patches from experts on other copylefts, such as
> MPL.

The reality is that most interest in copyleft wrt software focuses on
the GPL family, and in the aggregate non-GPL-family copyleft usage is
relatively small, though significant enough to be notable (and
conspicuously missing if absent) in a text on copyleft. I wonder then
whether there should be an explicit focus on the GPL family,
particularly GPLv2 and GPLv3 and LGPLvn.m, along with a special
chapter on well-known (and maybe some non-so-well-known)
non-GPL-family copylefts. It's also worth noting that the known
history of enforcement of non-GPL-family copyleft licenses is
essentially nonexistent, as it were.

Maybe there's enough for a separate chapter on non-GPL-family
non-software-oriented copyleft licenses (principally the various
versions of CC BY-SA).

bkuhn and I had some discussion of the general issue here, in advance
of Teg's message, during the past two days (I was in New York at an
event at which bkuhn was also present). Such discussions would be
covered under HBR were copyleft.org to adopt HBR. :)

RF