[erlang-questions] GNU GPL, MIT, BSD and compatibility
Thu Apr 10 11:11:07 CEST 2008
Il giorno gio, 10/04/2008 alle 10.45 +0200, Richard Carlsson ha scritto:
> Alceste Scalas wrote:
> > The GNU GPL does *not* require that the linked software is released (or
> > re-licensed) under the terms of the GNU GPL itself.
> Really? Here's what the GPL (v2) says:
> b) You must cause any work that you distribute or publish, that in
> whole or in part contains or is derived from the Program or any part
> thereof, to be licensed as a whole at no charge to all third parties
> under the terms of this License.
> As far as I can see, this is rather clear: *if* you distribute the derived
> work, then all of it *has* to be provided under the GPL ("this License"),
"As a whole" refers to the final product (as I called it in my previous
email) taken in its entirety. But it may be composed by parts (e.g.
code portions) that, taken alone, have different (albeit GNU
In fact, as you report, the GNU GPL v2 also says that:
> "These requirements apply to the modified work as a whole. If identifiable
> sections of that work are not derived from the Program, and can be
> reasonably considered independent and separate works in themselves, then
> this License, and its terms, do not apply to those sections when you
> distribute them as separate works. But when you distribute the same sections
> as part of a whole which is a work based on the Program, the distribution of
> the whole must be on the terms of this License, whose permissions for other
> licensees extend to the entire whole, and thus to each and every part
> regardless of who wrote it."
The GNU GPL v3 has the same conditions with different wording.
> The LGPL differs in that it does not consider code that merely links to
> your program to be a derived work.
Well, not exactly. Under the copyright law, a program that
depends/links to a library *is* a derived work, and thus it must observe
the licensing requirements of the library itself. Unlike the GNU GPL,
the GNU LGPL does *not* require that the derived product is released "as
a whole" under compatible licensing terms --- even if it *does* require
that modifications to the library itself are released under compatible
Alceste Scalas <>
CRS4 - http://www.crs4.it/
More information about the erlang-questions