Re: Ada 95 - the interpretation of the Gnu 'copy left'

[dewar@merv.cs.nyu.edu (Robert Dewar)]

John Lindsay said

<<Well, this is good; thanks to Robert and one other who
corrected my understanding.  But I read a copy of the
'copy left' some time ago with exactly this question and
a related question - can the Gnu compilers &c. be used to
create software to be distributed at all without also
distributing the whole particular Gnu package used to
create it - in mind.  My understanding (incorrect - separate
arrangements needed to use for profit, correct - no need to
redistribute the whole thing) came from that reading.
The copy left is verbose, perhaps necessarily so, and
perhaps it has been reworked since I read it.  I wonder if
a short 1-paragraph plain English explanation is needed to
accompany it, not in any way replacing or modifying the
full 'legal' text.
>>


I don't think a one paragraph summary would be likely to be helpful. I 
think most people understand quite clearly that the issue arises with
runtime routines only (to think that the GPL somehow covers the *output*
of the compiler makes no sense at all. Think by analogy, suppose I gave
you a GPL'ed financial program, comparable to Quicken, do you think the
fact that it was under the GPL means that you have to distribute your
checking records to the world, certainly not. The fact that the output
of a compiler is object code rather than checks makes no difference!

The only issue is the runtime, but the runtime is not under the GPL, due
to the special exception paragraph:

-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 2,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
-- for  more details.  You should have  received  a copy of the GNU General --
-- Public License  distributed with GNAT;  see file COPYING.  If not, write --
-- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
-- MA 02111-1307, USA.                                                      --
--                                                                          --
-- As a special exception,  if other files  instantiate  generics from this --
-- unit, or you link  this unit with other files  to produce an executable, --
-- this  unit  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 Public License.                                      --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --

Robert Dewar
Ada Core Technologies