LibreDWG: High Priority Projects List
Felipe Sanches
There is a brazilian guy who develops FreeCAD, a free software CAD, -
see its licensing page for the details please [1] - and we (Felipe
Sanches and Rodrigo Rodrigues, also from Brazil) are developers of a
GPLv3 library for handling DWG files (proprietary file format from
AutoCAD).
He contacted us to talk about usage of our library in his software.
I am emailing you for 3 reasons:
1) it is relevant for FSF since free software support for DWG file
format is one of the items in the high priority projects list
2) it is not clear to me whether FreeCAD convoluted licensing scheme
is OK with the GPLv3
3) it is not clear to me whether it is good in general for the free
software movement to have FreeCAD as a user of our library.
waiting for your comments,
Felipe Sanches
[1] http://sourceforge.net/apps/mediawiki/free-cad/index.php?title=Licence
(it will certainly annoy you since he insists in the "open source"
term and attitude. It annoys me too.)
PS: maybe you can understand the original message below (from Yorik
van Havre - the FreeCAD guy) since brazillian portuguese is similar to
spanish.
PS2: I'm sending a copy of this message to Alexandre Oliva from FSFLA
and to PoliGNU (our free software studies group at University of São
Paulo) because they might be also interested in this discussion.
---------- Forwarded message ----------
From: Yorik van Havre <yorik.v...@gmail.com>
Date: 2009/7/10
Subject: libredwg
To: rodrigo...@gmail.com, juca...@users.sourceforge.net
Olá pessoal,
Participo de um projeto chamado FreeCAD ( http://free-cad.sf.net )...
Estava dando uma olhada na libredwg, acabei de compilar, parece bem
interessante. Faz tempo que ando estudando possibilidades de suportar
arquivos dwg, como vocês sabem, não é nada simples...
Tentei falar com o cara da libdwg também, mas não consegui. Para falar
a verdade, achei um pouco difícil a história do esperanto.
A gente trabalha muito com python no freecad, assim que tiver um
tempinho vou tentar fazer um módulo para poder usar o libredwg a
partir de python, parece relativamente simples de fazer (sou meio
novato em c), mas bom, queria só fazer contato e agradecer/parabenizar
o esforço... Falei um pouco com o Matt Lee no FISL sobre a historia do
dwg, mas acabei de ler que vcs encontraram o Stallman (eu não consegui
chegar perto!)... Pena que não tinha ouvido falar do libredwg ainda!
Bom, abraços ai, mantenho vocês informados se consigo algo interessante.
Yorik
Yorik van Havre São Paulo Brazil http://yorik.orgfree.com +5511 3214
6330 +5511 9487 0628
Richard Stallman
It appears that parts of Freecad are under the GPL and parts under the LGPL.
But which versions of the GPL? It does not say.
If it is "GPL 2 only" then he can't link it with your library. If it
is "GPL 2 or later" then he can link with your library. It is that
simple.
He seems to say he believes that using the LGPL for some modules is
necessary so he can use the non-free nVidia driver. But that is
surely not true. That driver goes in X, not in his program. The
license of his program has no connection with whether he can use that
driver.
Maybe explaining this to him could help change his mind. Or maybe not.
Or maybe I misunderstood what he said about it.
3) it is not clear to me whether it is good in general for the free
software movement to have FreeCAD as a user of our library.
I see no reason to seek to prevent it. FreeCAD IS free software.
But you should not change the license of your library. Rather, it is
best to make it clear to him what the conditions are.
jriegel
since I'm the maintainer of FreeCAD and get cited here I take
change. :-)
1) Its nice you are a priority project.
2) FreeCAD is mainly under LGPL2 and portions under GPL2, so I think
you can
calm down.
3) If its not good for your library to be used in a OpenSource CAD
system for
what is it good for anyway?
To here it annoys you to here about my reasons for the licenses I
choose is
interesting, since it seems to be OK for you to bother Richard
Stallman with it.
What annoys me as an maintainer of a project ,which use 20+ OpenSource
libraries
each with an different license, is the constant hassle to get it work
together.
We have this endless discussions with the Debian guys, so if its good
for them
it shut be good for you.
Jürgen
Felipe Sanches
2) FreeCAD is mainly under LGPL2 and portions under GPL2, so I think
you can
calm down.
well... in order to use our lib, GPLv2 is not enough. To link with our code your program should be at least under GPLv3. I strongly suggest that you adopt "GPLv3 or later", but the "or later" part is optional and only useful for similar cases in the future to avoid trouble when we eventually get a GPLv4 license (if we ever need it).
Felipe
Yorik van Havre
Yorik
Rodrigo Rodrigues da Silva
Rodrigo
--
Rodrigo Rodrigues da Silva
Engenharia de Computação - Coop8
"Free software is defined as software that respects four fundamental freedoms: (0) freedom to run the software as you wish, (1) freedom to study the source code and modify it to do what you wish, (2) freedom to make and redistribute copies, and (3) freedom to publish modified versions." Richard Stallman
"Não importa como morre o home, importa como vive." Carijó, velho do rio.
jriegel
Yorik is right, if he make a python module it doesn't matters.
I never heard of that you can not use GPL2 and GPL3 together?
would be prevent all big projects to use your lib, because we
have always some GPL2 components (in case of FreeCAD Coin or
SketchFlat).
GPL3 is not widely adopted so far.
To use the GPL for a library is anyway a bit hard. There is
not much Libre left to use your software....
Anyway, its not on us to do that discussion. If FreeCAD use
your Lib and it comes to a Debian package, we meet again.
Jürgen
Richard Stallman
> you can
> calm down.
Since the library is under GPLv3 or later, the code people want to
combine with it needs to allow GPLv3 use also.
For instance, code under "GPLv2 or later" allows this. So does code
under LGPLv2. That code can be combined with your library.
However, "GPLv2 only" code cannot be combined with this library.
In another message you mentioned that Yorik was talking about using
the library "as a Python module". That would not change the issue.
Precisely how the library and the other code are combined into one
program is just a technical detail. The license issue is the same
either way.
I have cc'd Brett Smith of the FSF who can help explain these issues
further.
Rodrigo Rodrigues da Silva
>
> Since the library is under GPLv3 or later, the code people want to
> combine with it needs to allow GPLv3 use also.
>
> For instance, code under "GPLv2 or later" allows this. So does code
> under LGPLv2. That code can be combined with your library.
It is not clear to me what would be the resulting license of this program.
That is, once linked with a GPLv3 code, would the once "GPLv2 or later"
licensed code necessarily become GPLv3?
--
Rodrigo Rodrigues da Silva
PoliGNU
Richard Stallman
That is, once linked with a GPLv3 code, would the once "GPLv2 or later"
licensed code necessarily become GPLv3?
The licensse of the combination would be GPLv3 (or perhaps "GPLv3 or
later"). Each piece, considered separately, would continue to have
whatever license it says it has.
jriegel
then its clear. Since Coin3D is GPL2 only FreeCAD can not use
LibreDWG. Since I have no influence on Coins license we run out of
options. But that means also that a library licensed under GPL V3 is
very hard to use, at least in a bigger project like ours.
Sad!
Jürgen