GPL, BSD, commercial

Michele Bosi michele.bosi at
Wed Apr 1 08:34:30 UTC 2009


thanks for your kind reply,

section 5 or the LGPLv21 states:

"A program that contains no derivative of any portion of the
Library, but is designed to work with the Library by being compiled or
linked with it, is called a "work that uses the Library".  Such a
work, in isolation, is not a derivative work of the Library, and
therefore falls outside the scope of this License."
" When a "work that uses the Library" uses material from a header file
that is part of the Library, the object code for the work may be a
derivative work of the Library even though the source code is not."

So, based on the lines above: let's say I accept the LGPL version of
the license for library B to develop file F of my program A, since I
want to distribute/sell only the sources of my program A, not the
binary, and since I don't even need to redistribute the Library B (it
is optional to make my program work) it looks like the sources of file
F fall outside of the LGPL license, so I can license them with
whatever license I want, right? then if my customer decides to use
library B in combination with my program A and generates a binary
he/she has the responsibility to comply with whatever license of B
he/she is using I think, is it correct?



On Wed, Apr 1, 2009 at 9:55 AM, Matthew Flaschen
<matthew.flaschen at> wrote:
> Michele Bosi wrote:
>> Hello everyone,
>> I developed an opensource program A which uses a library B distributed
>> with 3 licenses, GPL3, LGPLv2.1 and a "commercial" one for
>> closed-source development. For the development a file F of my program
>> A I used the GPL3 version of library B. I was wondering if I can
>> distribute (and maybe even sell) the sources of my program A
>> (including F) using just any license like for example the BSD or if I
>> *have to* distribute F separately with the GPL3 license sice I used
>> the GPL3 version of the library B to develop it.
> Well, before distributing you first need to decide which license to
> accept, GPLv3, LGPLv2.1, or the proprietary license.  All three drive a
> different "bargain".  Probably, you'll be best off with the LGPLv2.1.  I
> believe that in that case, you could take advantage of LGPL sections 4,
> 5, 6.  This should let use the license of your choice for A as long as
> it permits private modification and reverse engineering.
> Don't worry about the fact that you've been working with the GPL
> download.  You don't have to abide by the terms of the GPL unless you
> modify or distribute the GPL code.  More practically, no one is going to
> sue you unless you distribute without complying with /any/ of the licenses.
>> The second question is: if for example I sell my program A (including F) to a customer
>> with a commercial license written by me, will he/she be able to
>> develop closed-source produtcs?
> That depends on which of B's licenses you accept, as well as the terms
> of your own proprietary license.
>  My answer to this last question is "yes" as long as my customer has
> also a "commercial license" of
>> library B and as long as the sources of my file F are available for
>> the others under the GPL3 (to fulfill the GPL3 requirements induced by
>> the use of library B)
> If you and your customer both have proprietary licenses for B, GPL is
> not in the picture.  In that case, it depends solely on the terms of B's
> proprietary license.  If you accept and distribute B under the LGPL, you
> can probably license A under a proprietary license, again as long as
> private modification and reverse-engineering are allowed.
>> Another way to reformulate this last question might be: if I develop a
>> program which uses a GPL3 library and I release the source code of my
>> program under the GPL3 license, can I also release/sell closed-source
>> commercial licenses for the same program to the customers that request
>> for it in order to develop closed-source programs?
> Probably not.  If you accept the library under the GPLv3, you can not
> distribute proprietary derivatives.  That is not the same question. :)
> I am not a lawyer and this is not legal advice.
> Matt Flaschen

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