[Freegis-list] Clearing up the terralib/terraview discussion.

Adrian Custer acuster at nature.berkeley.edu
Fri Oct 24 21:04:02 CEST 2003

Hey all,

We are all suffering from a language gap and from the past discussions
over this software. It seems to me that *everyone* means well. Everyone
who is reading this please note that the software being distributed as
TerraLib has changed since the eariler discussion and many of your
earlier notions no longer apply. The current software is distributed as
a single tarball with a note on the website that it is to be considered

This is an effort to clear this up once and for all. Plese, let's work
in as gentle a manner as possible. The group that created Terra*, and
Dr. Camara in particular, include people we really want to encourage to
participate in the FreeGIS effort. 

First of all, Dr. Camara has repeatedly claimed and suggested that
TerraView is also free software. We simply need to clear up why he
thinks it is, and why others think its not and come to a resolution.

Secondly, and from an outsider view, it looks like this group is moving
in the right direction. The group worked on SPRING which looks like it
must be a pretty cool piece of software. SPRING is not free, I suspect,
by historical accident more than philosphical persuasion. It's free in
free beer which, while a minor freedom in free software, shows that the
intent was not far from true free software. Note that SPRING was
released several years ago, long before, one suspects, the arguments for
free software would actually register in an institution like Brazil's
INPE. That Dr. Camara and his group have managed to move Terralib to the
lgpl is a *huge* step.

Could we in the FreeGIS community send an email to Dr. Camera and his
group laying out what our reservations are?  Here is my example email,
if suggestions could go to the list, I would appreciate it. Then perhaps
one of the core FreeGIS'ers can actually send it on our behalf. I have
cc'ed Dr. Camara to this email since I believe it will explain better
what is going on. 

Please, Dr. Camara note that others may want to add to this
explaination; in the current state this is merely my understanding.
Also, as an aside I am quite taken by you work on map algebras and hope
to think more about them in the future.

Dear TerraView team,

Congratulations on releasing TerraLib as free software, and thanks for
the great work. 

We at the FreeGIS project ( http://www.freegis.org ) are still slightly
confused by the license scheme of your software, partly because of how
terraview interacts with the Qt library which has its own set of legal
restrictions. If you would be willing to work with us to clear this up,
we would appreciate your effort and we would then better be able to
promote the part of your work that we truely felt was free software.

I. Applying the LGPL:

You clearly intend to release all of this software under the LGPL. You
state on your web site, under "Downloads" "Copyright":

"This library is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation - version 2.1."

While this should be sufficient to assume all your software is indeed
released under the LGPL, simply making this assumption is not a smart
legal strategy. To make things safer for everyone, the LGPL asks you to
do several things if you want to use it. (Please see:
http://www.gnu.org/copyleft/lesser.html#SEC4  ). Specifically, the LGPL
asks you to:

1) start each file with a statement that it's LGPL.

2) include the LGPL in your tarball. (At the bottom of the statement to
be included in every file are the words: "You should have received a
copy of the GNU Lesser General Public License along with this library".)

Looking at a few of the files in your tarball, none of them start with
the license statement, and your tarball as a whole does not contain the
LGPL. It will require some simple but boring work to change this but
it's actually important for various legal jurisdictions. For instance,
one of us, Adrian Custer, could not safely use your work because he
could not be sure that under california law he would be protected.

Once you have taken these two steps, we would all consider your software
*code* to be free and could use parts of it to develop other

II. Conflicts with Qt:

However, there is one additional problem which seems to several of us to
prevent the compiled result of your code (that is the functional
program) to be considered free. The problem is complicated but
sufficiently important that it currently prevents us from contributing
to and expanding on your work.

This arises, not because of your efforts, but because of Trolltech's
license and its interaction with your code. Trolltech gives you the
right to use Qt as a free software library *only* if you release your
software under the GPL (not the LGPL which you use). There would be
several ways to resolve this problem but each solution requires work and
you would have to decide what you intended to do.

1) you could simply release all your software under the GPL instead of
the LGPL. You would have to do steps (1) and (2) above using the GPL
instead of the LGPL.

2) you could split your software into two packages and relase TerraLib
as LGPL software and TerraView (all the pieces that use Qt) as GPL
software. Again you would have to do steps (1) and (2) above for each
piece. To make sure there was no confusion, it would be best then to
split the two projects.

3) you could switch from the Qt library to another library, like GTK+,
which is released under the LGPL and therefore does not lead to this

( To the freegis group: ANY OTHER SUGGESTIONS? )

We realize that we are asking you to do a fair amount of work but
believe that as a result of this work your software will become more
useful to a larger audience. We are all comitted to helping each other
build world class software for use in geographic information systems.
Please realize that free software is sometimes legally complicated but
that all projects must resolve these issues to be successful.

Thanks again for your contributions and we look forward to hearing from
you what you have chosen to do,

The FreeGIS Collaboration including:

Adrian Custer


P.S. So this took longer than I had hoped. Free Software can be work!

On the good side, I just got JUMP running correctly recently and am
*very* excited about the next year in the Free GIS world. I will soon be
able to teach GIS exclusively with free software and free data which is
a HUGE step forward. 

All the best,

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