[erlang-questions] GNU GPL, MIT, BSD and compatibility
Thu Apr 10 16:43:41 CEST 2008
Just for reference:
But, mind you, I don't think that everyone agrees with this
interpretation and it this (as far as I know) has not been tested in
This is one of the problems I have with the GPL though - it is
complicated enough that I am not sure what it says exactly.
On Thu, Apr 10, 2008 at 6:37 AM, Alceste Scalas <> wrote:
> Il giorno gio, 10/04/2008 alle 13.39 +0200, Richard Carlsson ha scritto:
> > Yes, and they mean that *if* you distribute the work, *including* the GPL
> > parts, then *all* parts, including those that come under non-GPL (but
> > compatible) licenses, must be made available *under the GPL*. (Assuming
> > all involved licenses allow the combination to be made.)
> > Hence, the only way a license can be GPL-compatible is if it allows
> > redistribution under GPL.
> Yes. Maybe we were trying to say the same thing.
> There is one point that I wanted to clarify, though (based on the wrong
> GNU GPL assumptions that started this sub-thread): the GNU GPL does
> *not* require you to license (or re-license) your code under the GNU GPL
> itself. If your code is under a MIT-like license, it won't be
> > "What does it mean to say a license is "compatible with the GPL?"
> > - It means that the other license and the GNU GPL are compatible; you
> > can combine code released under the other license with code released
> > under the GNU GPL in one larger program.
> > All GNU GPL versions permit such combinations privately; they also
> > permit distribution of such combinations provided the combination is
> > released under the same GNU GPL version. The other license is compatible
> > with the GPL if it permits this too."
> > Note: "provided the combination is released under the same GNU GPL version".
> > *Not* just any "GNU GPL-compatible licenses" as you wrote.
> Yes, it refers to the combination "as a whole". But, as I wrote, its
> parts taken alone may be covered by different, GNU GPL-compatible
> licenses. If program "bar" is under MIT and depends on the GNU GPL'ed
> "libfoo", then "bar + libfoo" must be distributed complying with the
> terms of the GNU GPL. This fact, however, does not require to
> change/infect the license of "bar" taken alone.
> > The EPL is not GPL-compatible, and Erlang modules are dynamically linked,
> > so it is not possible to use GPL:ed Erlang modules if you want to distribute
> > the result. LGPL should be ok for Erlang code, however.
> But Erlang does *not* derive/depend on GNU GPL'ed modules: it just has
> the capability to load them and make them available to Erlang programs.
> The GNU GPL FAQ suggests a different conclusion about GNU GPL'ed Erlang
> If a programming language interpreter is released under the GPL,
> does that mean programs written to be interpreted by it must be
> under GPL-compatible licenses?
> [W]hen the interpreter is extended to provide "bindings"
> to other facilities (often, but not necessarily,
> libraries), the interpreted program is effectively
> linked to the facilities it uses through these bindings.
> So if these facilities are released under the GPL, the
> interpreted program that uses them must be released in a
> GPL-compatible way. The JNI or Java Native Interface is
> an example of such a binding mechanism; libraries that
> are accessed in this way are linked dynamically with the
> Java programs that call them. These libraries are also
> linked with the interpreter. If the interpreter is
> linked statically with these libraries, or if it is
> designed to link dynamically with these specific
> libraries, then it too needs to be released in a
> GPL-compatible way.
> Thus, you *can* develop GNU GPL'ed Erlang modules, or modules that link
> to GNU GPL libraries, and load them on the Erlang VM. But the Erlang
> programs that actually link/depend on them must be released under a GNU
> GPL-compatible license.
> > > Under the copyright law, a program that depends/links to a library
> > > *is* a derived work,
> > Which "the copyright law"? Quote, please.
> > > Unlike the GNU GPL, the GNU LGPL does *not* require that the derived
> > > product is released "as a whole" under compatible licensing terms
> > No, in fact the LGPL quite explicitly says what a derived work is: [...]
> D'oh, you're right. I did not check the license, and remembered it
> Alceste Scalas <>
> CRS4 - http://www.crs4.it/
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