Python programs always open source?

[Chris Lambacher]

On Tue, Sep 19, 2006 at 09:46:13PM +1000, Ben Finney wrote:
> "Diez B. Roggisch" <deets at nospam.web.de> writes:
> 
> > Ben Finney schrieb:
> > > My claim (and IANAL) is that it doesn't matter *what* license
> > > Python is distributed under; unless you do something with Python
> > > that is a right of the copyright holder, such as distributing part
> > > or all of Python, the copyright license terms of Python have no
> > > legal effect on what license you choose for your own work.
> >
> > Not true for the GPL. Part of python is the library, which you
> > either use explicit (I can't imagine a program that doesn't, beyond
> > print "hello world"), or implicit (sys and os are AFAIX used
> > internally to bootstrap the interpreter)
> 
> And just about every program on a GNU/Linux system uses the libc
> library, which is distributed under the GPL. That license *only*
> affects works that are *derivative* of the libc library.
Hmmm... The copyright file I have for GNU C Library looks to be LGPL:
"""
    Copyright (C) 1991,92,93,94,95,96,97,98,99,2000,2001,2002,2003 Free Software
    Foundation, Inc.

       The GNU C Library is free software; you can redistribute it and/or
       modify it under the terms of the GNU Lesser General Public
       License as published by the Free Software Foundation; either
       version 2.1 of the License, or (at your option) any later version.

       The GNU C Library is distributed in the hope that it will be useful,
       but WITHOUT ANY WARRANTY; without even the implied warranty of
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
       Lesser General Public License for more details.
"""

The difference between the GPL and the LGPL is the linking thing.  Whether or
not it would hold up in court the FSF believes that GPL libraries mean only
GPL or GPL compatible licences are allowed to link, while anything can link
(dynamically not statically) to LGPL libraries.
http://www.gnu.org/licenses/why-not-lgpl.html:
"""
    Proprietary software developers have the advantage of money; free software
    developers need to make advantages for each other. Using the ordinary GPL for
    a library gives free software developers an advantage over proprietary
    developers: a library that they can use, while proprietary developers cannot
    use it.

    Using the ordinary GPL is not advantageous for every library. There are
    reasons that can make it better to use the Library GPL in certain cases. The
    most common case is when a free library's features are readily available for
    proprietary software through other alternative libraries. In that case, the
    library cannot give free software any particular advantage, so it is better to
    use the Library GPL for that library.
"""

> 
> > And the GPL exactly requires that when a library licensed under it
> > is used, that makes the using program GPL-licensed, too.
> 
> No, only when a new work *derives from* the existing work does
> copyright on the existing work take effect.
> 
> You may be thinking of the "linking" clause, which depends on the
> *inclusion of* existing header files from the library code, supplied
> under the GPL. There's no such concept in an interpreted language like
> Python: you write your program in the Python language without
> including a single piece of the original in your work.
> 
> The GPL itself is clear on the fact that its terms cannot claim
> anything that is not granted to the copyright holder -- and
> *execution* of a library is not a right over which the library author
> has any rights.
> 
> Even if execution (or "use") of a program library, without including
> *any* of its code in your own work, were a right the library author
> could restrict, no free software program can place any restriction on
> execution (otherwise it's trivially non-free). If Python's license
> were ever to have such a restrictive term, it would likely be
> unenforcible, but would certainly disqualify it from inclusion in any
> free operating system.
> 
> Copyright is currently weighted greatly in favour of copyright
> holders, but please don't buy into the absolute-power rhetoric more
> than necessary.
> 
> -- 
>  \       "Yesterday I told a chicken to cross the road. It said, 'What |
>   `\                                          for?'"  -- Steven Wright |
> _o__)                                                                  |
> Ben Finney
> 
> -- 
> http://mail.python.org/mailman/listinfo/python-list