Subject: readline & GPL
From: Stephen Turnbull <>
Date: Mon, 18 Oct 1999 01:13:46 +0900 (JST)

>>>>> "Peter" == L Peter Deutsch <> writes:

    Peter> Well, right now rms is saying that non-GPL'ed programs
    Peter> can't be linked with GNU readline even if the result isn't
    Peter> distributed

No, that's not what he is saying, AFAIK.  What he is saying, I
believe, is that if _you_ (or a third party) provide a mechanical
means (eg, a module using the GNU readline API and an appropriate
Makefile fragment) to "automatically" create a binary containing both
GNU readline capabilities and non-GPL'd code, _you_ (or a third party)
may only distribute that module and fragment along with a version of
Ghostscript that has been placed under the GPL.

However, I don't see any way the FSF can prevent you from organizing
the code in such a way that the module that needs to be replaced is of
minimal size.  From there, it's every user for herself, but of course
she cannot distribute the result.  So programmers willing to spend a
little effort can have it, but ordinary users can't.  In fact, as long
as the interpreter/whatever-readline interface remains frozen, there
will always be a reasonably up-to-date module available in GNU
Ghostscript, making it trivial for anyone who can edit the makefile
(although it's infringement for anyone to share their makefile-munging
scripts with anyone else :( ).

I've also toyed with the idea of converting GNU readline into an XIM
external input method.  For it to be really useful I'd have to create
an Xlib-less client XIM library, but once that was done, GNU readline
and Ghostscript would be separate processes, communicating via the XIM
protocol over Unix IPC or sockets or whatever.  The GNU readline XIM
server would have to be GPLed, of course, but that should put an LGPL-
like Chinese wall between "Clause 6" and your software.

University of Tsukuba                Tennodai 1-1-1 Tsukuba 305-8573 JAPAN
Institute of Policy and Planning Sciences       Tel/fax: +81 (298) 53-5091
What are those two straight lines for?  "Free software rules."