On 4/20/10 3:49 PM, Brendan Miller wrote:
On Tue, Apr 20, 2010 at 11:38 AM, Robert Kern<robert.k...@gmail.com> wrote:
On 4/20/10 1:09 PM, Brendan Miller wrote:
Python provides a GNU readline interface... since readline is a GPLv3
library, doesn't that make python subject to the GPL? I'm confused
because I thought python had a more BSD style license.
The PSF License is more BSD-styled, yes. The readline module can also be
built against the API-compatible, BSD-licensed libedit library. Python's
source distribution (even the readline module source) does not have to be
subject to the GPL, though it should be (and is) GPL-compatible.
Also, I presume programs written with the readline interface would
still be subject to GPL... might want to put a warning about that in
the python library docs.
*When* someone builds a binary of the Python readline module against the GNU
readline library, then that binary module is subject to the terms of the
GPL. Any programs that distribute with and use that binary are also subject
to the terms of the GPL (though it can have a non-GPL, GPL-compatible
license like the PSF License). This only applies when they are combined with
the GNU readline library, not before. The program must have a GPL-compatible
license in order to be distributed that way. It can also be distributed
independently of GNU readline under any license.
Hmm... So if I ship python to a customer with proprietary software
that runs on top of it, then I need to be careful to disable
libreadline? Is there a configure flag for this or something?
Just don't ship the readline.so module. That's the only thing that links to
libreadline.
Since libreadline is the default for Linux systems, and Python's
license advertises itself as not being copyleft, and being embeddable
and shippable... It would be nice if this were made clear. Maybe a
note here about libreadline: http://python.org/psf/license/
http://bugs.python.org
It seems to me that the whole of the python distribution would be GPL
after being built with libreadline, so this would be an easy trap to
fall into if you didn't realize that python used libreadline.
No, the whole Python distribution does not magically become GPLed because one
optional module that you may or may not load is compiled against a GPLed library.
--
Robert Kern
"I have come to believe that the whole world is an enigma, a harmless enigma
that is made terrible by our own mad attempt to interpret it as though it had
an underlying truth."
-- Umberto Eco
--
http://mail.python.org/mailman/listinfo/python-list
