Re: proposed FAQ entries about licensing

[Judd Storrs]

On Thu, Apr 9, 2009 at 2:44 AM, Jaroslav Hajek <address@hidden> wrote:
> Suppose I write an m-script that uses Octave's unique features (like
> specific block ends), which, according to a general agreement, will
> then be a derivative work, and then later Matlab (or Scilab or
> whatever) is updated so that the script can be run in Matlab, will it
> cease to be Octave's derivative work?

Do you also consider a bash script to be a derivative of bash?

> No, not the interface. I think that it is the internal link to
> Octave's libraries that makes it a derivative work. Maybe it's a
> nonsense, but I don't really understand how the situation is
> different, say, from dynamic linking to GNU libc (assuming a program
> does not use glibc-specific features). If such a link is not relevant,
> then why is GNU libc under LGPL?

Exactly. I think you're 100% correct here. The reason the LGPL was
created was to allow dynamic linking of proprietary software with
libc. It is a GPL violation to distribute software that dynamically
links GPL-incompatible software into a GPL library or executable.

I think the classic example of this is GNU readline which is GPL and
has tripped up some people in the past. Sometimes they remove readline
support, sometimes they relicense their code under GPL.

http://clisp.cvs.sourceforge.net/*checkout*/clisp/clisp/doc/Why-CLISP-is-under-GPL
http://www.fsf.org/licensing/licenses/why-not-lgpl.html

>> Yes, but maybe we should consider changing that.  Since someone else
>> could just create their own file containing all the same mx* and mex*
>> prototypes and place it in the public domain, I don't see that keeping
>> Octave's mex.h file under the GPL has much of an effect.
>
> But can it be done, when we distribute it along with GPLed sources?
> Doesn't that make it automatically GPL-covered?

I'm not really up to speed with GPLv3, but it would be a major change
from 2.0 if the GPL now requires that all parts distributed with
octave must be GPL. I think the requirement is that the code is
GPL-compatible, but it could well be less restrictive than the GPL. As
far as examples go, GNU bison and flex have some files with exceptions
that allow bison and flex to be used to build proprietary code.

I can investigate Matlab's license terms if anyone is interested.

--judd