Re: Plugins, libraries, licenses and Debian

[bts@alum.mit.edu (Brian T. Sniffen)]

mru@kth.se (Måns Rullgård) writes:

> What I'm trying to find out is, whether or not it's allowed to write a
> plugin, using GPL,d libraries, for a program with MIT license, for
> which there also exists plugins using OpenSSL (or anything
> GPL-incompatible).

Write it?  Sure.  Distribute the whole thing as a package together?
Probably not.  For example, Microsoft shouldn't be able to package up
all the proprietary bits of Word as one plugin, package Emacs as
another plugin, and write an MIT-licensed framework which includes
them both, then sell this as Microsoft EmacsWord.

In other words, if you make plugins only as a dodge around the
licenses, to attempt to claim these are separate works, that's not OK:
you're still creating a whole work which derives from the GPL'd works
and the OpenSSL work, which the authors of the GPL'd work don't want
you to do.

> While on the subject of intent, was it ever the intention of anyone to
> disallow programs using both readline and OpenSSL?  Or did they just
> happen to formulate their licenses in incompatible ways?

Yes.  It was the intent of the original GPL to be incompatible with
the BSD Advertising Clause, which is essentially what OpenSSL has.
GNU Readline is intentionally under the GPL and not the LGPL as a
cookie to tempt authors to use the GPL "License under the GPL and you
can get this great functionality at no extra cost!".  The excellent
GNU math libraries, similarly, are under the GPL and not the LGPL for
this reason.

-Brian