Re: guile+readline

[Andrew Archibald <aarchiba@undergrad.math.uwaterloo.ca>]

; > From: Andrew Archibald <aarchiba@undergrad.math.uwaterloo.ca>
; > - Is the Guile GPL similar enough to the GPL that it is legal to
; > construct a program that is a derived work of both? And still under
; > the GGPL?
; 
; There is no GGPL.  There is the GNU GPL and the GNU Library GPL.
; Guile has the Library GPL, which is the same as GPL with this
; special exception:

Actually, the Library GPL is a different beast entirely.  It is much
more detailed, and rather different (for example, you have to
distribute object code for your application).  It is also deprecated by the
FSF.  The recommended method is now to use the GPL with specific
exceptions for special use.  Guile uses such a license, called the
Guile General Public License, at least in release 1.2.

; I would say definitely, changing one procedure in a large program
; is making a derived work.  I do not know what you mean by
; the "any-license-you-like" part of GGPL.  Cite the GPL paragraph
; you are talking about.

Oh, I just meant that you can write a program that uses guile and has
any license you like.  You actually cited the paragraph... sorry I was
unclear. 

; > - Is a guile interpreter that uses readline a derived program of
; > readline?  
; 
; I'm not sure, but check the licence on readline.  If it is also under
; LGPL then the point is moot.

Unfortunately, it's not up to individual licenses to decide what is a
derived work.  It's up to copyright lawyers.  

The difficulty here is the readline is not under the LGPL, and there
are no exceptions in its license.  It is under the GPL, and the FSF
has been strict about it.  There have been proprietary programs
written to use readline; when the FSF found out, they warned the
author that they were in violation of the FSF's copyright.  In at
least one case, this resulted in the program being rereleased as
free.  (See www.gnu.org for no more details). 

<SOAPBOX> I think the FSF is making life more difficult for users in
exchange for slightly increasing the available free software base.  So
do they.  I think it's wrong, that the real reason for free software
is to make life better for software users.  But it's up to them. </SOAPBOX>

Hence the problem: people use guile in proprietary applications.  If
readline is standarldy linked in, can they legally do this?  If
readline is distributed alongside, in a convenient (easy to dynamically-link)
version, can they do this?  If readline is distributed separately, as
a dynamically loadable module, can they do this?  What if they write a
guile script which calls (make-readline-port)? Does this script have
to be GPLed?

These questions are a spectrum;  the basic question is, in the
presence of dynamic linking, especially at runtime, what constitutes a
dervied work?

In answer to another question:  many applications that use guile
require significant modifications to use guile.  In fact, once you've
got guile installed, there are a whole host of things that are easier
done in guile.  So applications that use guile tend to be very
dependent on guile, making it impractical to package them separately.

; Anybody can sue anybody, but I can't see the user suing for something
; ey did emself.  The FSF might sue for distributing copyrighted code in
; in violation of the licence.  Read the licence.  Consult a lawyer
; if you have a guilty conscience.  I am not one.

I just play with guile for fun...  no proprietary applications on my
conscience.  But it seems like red-bean.com may be distributing code
with incompatible licenses, hence illegally.  I'd like to clear this
up...

Thanks,
Andrew