Re: Octave FAQ update about GPL

[Felipe G. Nievinski]

On Thu, Feb 13, 2014 at 8:55 AM, John W. Eaton <address@hidden> wrote:

On 02/12/2014 05:23 PM, fgnievinski wrote:

Here it is.  Please don't get too annoyed by the verbosity -- there's some
redundancy, so that each usage case can be deemed true/false independently
from the others.  I'll wait for your okay, comments, changes before bugging
licensing at FSF.  I'll send in a separate message a discussion which I
think is too esoteric for the FSF folks.
-F.

[Label: using the Octave interpreter]
* Code written entirely in the scripting language of Octave (interpreted
code in .m files), that invokes only language keywords (such as "if",
"switch", etc): code may be released under the terms of whatever license you
choose.
- Source: <http://www.gnu.org/licenses/gpl-faq.html#IfInterpreterIsGPL>,
paragraph 1.

...
I suggest that you take a different approach here.  I know (at least some of) the people at the FSF who might help us with these issues.  I expect that it will be much easier for them to help us if we ask these questions in a different way.  Instead of writing FAQ entries and asking them to comment on or approve them, it would probably be better to look for two or three specific things that you want to clarify and ask specific questions about those cases using specific examples.  In
other words, a question like this:

  I have a program that works this way: ....  Does that mean it has to be released under the terms of the GPL?  I've looked at the FAQ and the answers to the questions A, B, and C seem to be related to this question, but don't seem to apply exactly.  My case seems different in this way: ..., and that's confusing me because of ....

OK, I'll start easy with only one question, and an extension:

- I have a program that works this way: it is written entirely in the scripting language of Octave (interpreted code in .m files), that invokes not only language keywords, but also calls library functions that are not part of the Octave interpreter itself, but are part of the core Octave runtime library and are distributed along with Octave, under the same terms as Octave (GPLv3+).  Does that mean that, if I choose to release my code publicly, it must be released under the terms of the GPL?  I've looked at the GPL FAQ and the answer to the following question seems to be exactly applicable, which I now quote -- please note specially the contrast between first and second paragraphs:

Q: If a programming language interpreter is released under the GPL, does that mean programs written to be interpreted by it must be under GPL-compatible licenses? 

A: When the interpreter just interprets a language, the answer is no. The interpreted program, to the interpreter, is just data; a free software license like the GPL, based on copyright law, cannot limit what data you use the interpreter on. You can run it on any data (interpreted program), any way you like, and there are no requirements about licensing that data to anyone.

...

Another similar and very common case is to provide libraries with the interpreter which are themselves interpreted. For instance, Perl comes with many Perl modules, and a Java implementation comes with many Java classes. These libraries and the programs that call them are always dynamically linked together. A consequence is that if you choose to use GPL'd Perl modules or Java classes in your program, you must release the program in a GPL-compatible way, regardless of the license used in the Perl or Java interpreter that the combined Perl or Java program will run on.

<http://www.gnu.org/licenses/gpl-faq.html#IfInterpreterIsGPL>

That's confusing me because of the current GNU FAQ states:

Q: If I write code using Octave do I have to release it under the GPL?

A: (...) Code written entirely in the scripting language of Octave (interpreted code in .m files) may be released under the terms of whatever license you choose. (...)

<http://wiki.octave.org/FAQ#If_I_write_code_using_Octave_do_I_have_to_release_it_under_the_GPL.3F>

A related case is if the called function library is not are part of the core Octave runtime library that is distributed with Octave. These third-party library functions are licensed under the GPL without any copyleft exception clauses (such as those adopted in the GCC Runtime Library or the GNU Classpath for Java).  Again, does that mean that, if I choose to release my code publicly, it must be released under the terms of the GPL?  The portion of the GPL FAQ quoted above seems to remain exactly applicable.