[erlang-questions] GNU GPL, MIT, BSD and compatibility

[Alceste Scalas]

Il giorno gio, 10/04/2008 alle 10.05 +0100, Alpár Jüttner ha scritto:
> > The GNU GPL does *not* require that the linked software is released (or
> > re-licensed) under the terms of the GNU GPL itself.
> 
> In fact, there there is a paragraph in GNU GPL that seems to define when
> it is not necessary to use GPL in your work using a GPL software:

>         A compilation of a covered work with other separate and
>         independent works, which are not by their nature extensions of
>         the covered work, and which are not combined with it such as to
>         form a larger program, in or on a volume of a storage or
>         distribution medium, is called an “aggregate” if the compilation
>         and its resulting copyright are not used to limit the access or
>         legal rights of the compilation's users beyond what the
>         individual works permit. Inclusion of a covered work in an
>         aggregate does not cause this License to apply to the other
>         parts of the aggregate.

It's a different matter: it refers to programs that do *not* depend/link
with GNU GPL'ed software.  I.e. if you want to distribute a GNU GPL'ed
program in a compilation of programs with incompatible licenses, then
you are allowed to (as long as you respect the GNU GPL, of course).


> Assume that Erlang is linked against a GPL lib. Is that an aggregation?
> (Then no GPL is necessary) Or it "is combined with it such as to form a
> larger program" (Then Erlang seems to be requested to use GPL)? It is
> far too fuzzy for me.

If it was not fuzzy, we would not have lawyers around :-)

If the Erlang functionality depends on some GNU GPL'ed library (example:
GNU Readline), then the resulting program is a derived work that must
respect the terms of all the licenses involved --- including the GNU
GPL.  Thus, *all* of its parts must be covered by GNU GPL-compatible
licenses.

I know (but I've not verified) that the Erlang Public License is *not*
GNU GPL-compatible, because it includes some restriction that the GNU
GPL does not impose.  If this is true, then you are not legally allowed
to create a "whole" by linking EPL'ed code and GNU Readline, because you
would not be able to distribute that "whole" under the terms of the GNU
GPL.

(NOTE: "distributing under the terms of the GNU GPL" does *not* mean
"relicense all the components under the GNU GPL").

Regards,

alceste
-- 
Alceste Scalas <alceste@REDACTED>
CRS4 - http://www.crs4.it/