Subject: Re: LGPL... variations on a theme
From: Ian Lance Taylor <ian@airs.com>
Date: 05 Jul 2001 11:05:34 -0700

Bernard Lang <Bernard.Lang@inria.fr> writes:

> On Wed, Jul 04, 2001 at 11:31:56PM -0700, Ian Lance Taylor wrote:
> > Bernard Lang <Bernard.Lang@inria.fr> writes:
> > 
> > > 2- Another organization is producing a free compiler, and an associated
> > > run-time library. The run-time library is LGPLed.
> > >    They are concerned that potential users will not like the
> > > constraint of the LGPL on "work that uses the Library" as described in
> > > section 6 of the LGPL, namely that one must provide a relinkable
> > > version of the program (so as to allow free modification of the
> > > library components used).
> > >    The problem is not so much that people do not want to give that
> > > freedom, but that the hassle of being contrained to do it for ever may
> > > discourage potential users at the onset of their project.
> > >    So the idea is to remove that constraint (possibly while
> > > encouraging people to do it anyway).
> > >    The idea is that a free system that is a bit more lax on GPLing is
> > > better than a dead system (they want, need their system to live).
> > >    I am not too keen on this, but I would welcome comments.
> > 
> > If you remove that constraint, then they can pretty much do anything.
> > They can modify the library, add all sorts of proprietary goop, and
> > then release a fully linked program without providing the source to
> > the modified library.  I'm not sure how this is different from the
> > libgcc exception license, which is the GPL plus this paragraph:
> > 
> >     In addition to the permissions in the GNU General Public License, the
> >     Free Software Foundation gives you unlimited permission to link the
> >     compiled version of this file into combinations with other programs,
> >     and to distribute those combinations without any restriction coming
> >     from the use of this file.  (The General Public License restrictions
> >     do apply in other respects; for example, they cover modification of
> >     the file, and distribution when not linked into a combine
> >     executable.)
> 
> Sorry, misunderstanding
> 
> The only constraint I consider for removal is the obligation to
> provide relinkable object code for the "work that uses the Library".
> 
> The constraint to release source code for everything in LGPL would of
> course stay.

Sorry, my misunderstanding.  They can modify the library, and release
an executable linked against the modified library, but they still have
to provide the sources to the modified library.  It doesn't help the
person with the executable, but it may help improve the library for
others.  This prohibits a proprietary fork, but it does permit people
to ship proprietary executables which use the library.  Off the top of
my head I can't think of another license like that.

Compare this to the libgcc license (the GPL with exception I mention
above).  The libgcc license prohibits using a modified version of the
library in a fully linked executable without sources.  It does permit
using the unmodified library in a fully linked executable without
sources.

I guess my question would be: what is the goal?  Do they want code
contributions?  Or do they just want their code to be out there?  If
they want contributions, the LGPL plus exception might be better than
the GPL plus exception.

Is it possible for them to release the library as a shared library?
That would let them use the unmodified LGPL.

Ian