Subject: Re: gpl backlash?
From: Ian Lance Taylor <ian@airs.com>
Date: 27 Jul 1999 17:38:10 -0400

   From: John Cowan <cowan@locke.ccil.org>
   Date: Tue, 27 Jul 1999 17:33:40 -0400 (EDT)

   > [T]he LGPL, the license under which the major libraries are
   > released, specifically allows non-free programs to link to binaries
   > under that license.

   The kernel, however (which is just another library), is under the GPL.
   I know that Linus explicitly states that the GPL's viral properties
   do not spread from the kernel to user-mode code, but I don't see how that
   can be made consistent with the GPL's claim that "changing it [the GPL]
   is not allowed."

Quite a bit of code is distributed with language like the following:

/* As a special exception, if you link this library with other files,
   some of which are compiled with GCC, to produce an executable,
   this library does not by itself cause the resulting executable
   to be covered by the GNU General Public License.
   This exception does not however invalidate any other reasons why
   the executable file might be covered by the GNU General Public License.  */

The FSF has approved this sort of exception.

The Linux kernel sources, unlike most FSF sources, do not appear to be
particularly rigorous in their use of copyright statements.  If they
were, they could simply add an exception along the lines of the above;
that is, the kernel would be covered by the GPL plus an exception for
user-mode programs calling into the kernel.

Ian