Re: [Gcl-devel] Re: [gnu.org #48656] Re: GCL compliance with GNU GPL

[Jong-Kyou Kim]

Hello Camm,

Regarding the following question, I'd like tell my experience when I tried to 
use clisp for developing a software system for a company.

> It appears we have several options:
> 
> 1) remove or replace readline in GCL and keep the LGPL
> 2) make use of the clause you cite below for a multiple license
>         strategy depending on whether readline is linked in.
> 3) make GCL GPL and add a note in the COPYING file allowing
>         proprietary images built with proprietary standard common lisp
>         code. 
> 
> My first question is concerning the difference in practice between the
> LGPL and the GPL with the clause as in 3).  Aren't they completely
> equivalent?  It would not appear that option 3) would pose a
> significant obstacle to anyone.
> 


Making proprietary image of CLisp is exempted only when it is independent work. 
Being an independent work, according to the licensing term, is that the work 
could run without referring any symbols except the ones in the package 
COMMON-LISP,
  COMMON-LISP-USER, KEYWORD, and EXT.

It means, as far as I understand, I cannot develop any system which uses socket 
connections since it uses socket package. I think this exception makes sense 
under GPL since CLisp, in this case, serves only as a substitute of any other 
common lisp platform and have little to do with the proprietary code.

To make industrial applications using GCL, threfore, I think it would be much 
better to license it under LGPL.

Best regards

Jong-Kyou

PS. After reading the e-mail between RMS and Sam, I think 2) could have some 
trouble. Even Sam proposed dual version of CLisp systems, one with readline and 
one without readline, RMS didn't agree that the one without readline could be 
released under LGPL.

Below is the part of the discussion (RMS> and SAM> are inserted to clarify who 
told what). For more details, you could refer 
http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/*checkout*/clisp/clisp/doc/Why-CLISP-is-under-GPL?rev=HEAD

--------- below ----------

    RMS> Readline's terms say that the whole program has to be under
    RMS> the GPL, and just having the user do the link doesn't change this.

    SAM> I don't agree. My lisp.a is not a "work based on libreadline.a". What I
    SAM> distribute is a "mere aggregation" of lisp.a and libreadline.a - the 
latter
    SAM> with source.

    SAM> I could provide a libnoreadline.a and let the user choose to link 
lisp.a
    SAM> with either GNU's libreadline.a or my libnoreadline.a . Would that 
convince
    SAM> you that lisp.a "can be reasonably considered independent and separate 
    SAM> work" ?

RMS> No, and I doubt it would convince a judge either.