Re: gnu readline / license

[Ethan M. <merritt@u.washington.edu>]

I do not believe that the GPL restricts gnuplot from being
linked against libreadline.  Debian apparently believes otherwise,
but that is their problem, not ours.  I don't think we should waste
any time over it.  Debian are waaaay out there on the extreme
of licensing paranoia.

1) gnuplot is clearly not a derived work of libreadline. I don't
think anyone is arguing this point.

2) It is my understanding that restrictions imposed by the
GPL do not cross a well-defined API boundary.  Therefore mere
linkage to  an independent (and optional) shared library does
not by itself contravene the GPL.  The most extensive discussion
on this issue that I have followed has been on the linux kernel
mailing list.  So far the broad (though not universal) consensus
is that non-GPL binaries can link against the GPL linux kernel.
This is a much tighter integration than our case of using 
libreadline as an optional adjunct to a software package (gnuplot)
that runs just fine even on platforms where libreadline does not
exist.

These arguments may well not sway Debian, who are (IMHO)
way over the top with regard to interpreting the GPL. But I do not
see that Debian's own policies, which are not widely shared even
by other linux distibutions, should control our actions for gnuplot.

Note that Fedora Core, Redhat, PLD, Mandrake, and SuSE
all seem perfectly happy distributing gnuplot+libreadline binary
packages.

On Wednesday 02 June 2004 01:34 am, Johannes Zellner wrote:
> Debian's gnuplot comes w/o gnu readline, which is very bad in my
> opinion. The reason is a license problem, which is documented by the
> package maintainer Thimo Neubauer <th...@de...> (in
> /usr/share/doc/gnuplot/README.Debian):
>
>     libreadline
>     -----------
>
>     Yes, the built in readline of gnuplot is bad. However, libreadline
>     cannot be used instead because it is licensed under the GPL, whereas
>     gnuplot has special licenses (patches only). Linking those programs
>     together is forbidden by the GPL. Please don't file bugs telling me
> to use libreadline in gnuplot...



-- 
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195