Re: GNAT GPL 2005 Edition

[David Trudgett <wpower@zeta.org.au.nospamplease>]

Jeffrey Carter <spam@spam.com> writes:

> Santiago Urue�a wrote:
>> I've just seen this at AdaCore's Libre site, and it seems it will be
>> released very, very soon!:
>> http://libre.adacore.com/gpl_notice.html
>> In my opinion this is great news for the entire Ada community, and
>> not
>> only for Free-software developers.
>
> Interesting. In the past, AdaCore's public releases were suitable for
> producing non-GPL SW. I wonder if "This new Edition will provide Free
> Software developers, that is developers that distribute their work
> under the GPL" means the runtime and libraries will be GPL, rather
> than GMGPL, forcing the resulting executables to be GPL.

Even if it is the case (and I have no idea) that the modified GPL is
not used, it still does not mean that resulting executables are
"GPL". It would only mean (at most -- see below) that those
executables couldn't be formally distributed except under the
GPL. This means that in-house proprietary software is completely
unaffected by the GPL.

    "The GPL permits anyone to make a modified version and use it
    without ever distributing it to others."

    ...

    "It is essential for people to have the freedom to make
    modifications and use them privately, without ever publishing
    those modifications."

    -- http://www.gnu.org/licenses/gpl-faq.html


That said, I believe the spirit of the GPL (applied to compilers like
GNAT) is (or should be) to protect the software itself (compiler) from
being hijacked by proprietary interests. The GPL doesn't apply to the
output of programs, and an executable binary is just the output of the
compiler. Therefore, according to this logic, programs compiled by a
GPL'ed compiler are not themselves under the GPL (unless you make them
so).

In that regard, note:

    Can I use GPL-covered editors such as GNU Emacs to develop
    non-free programs? Can I use GPL-covered tools such as GCC to
    compile them?

        Yes, because the copyright on the editors and tools does not
        cover the code you write. Using them does not place any
        restrictions, legally, on the license you use for your code.

        Some programs copy parts of themselves into the output for
        technical reasons--for example, Bison copies a standard parser
        program into its output file. In such cases, the copied text
        in the output is covered by the same license that covers it in
        the source code. Meanwhile, the part of the output which is
        derived from the program's input inherits the copyright status
        of the input.

        As it happens, Bison can also be used to develop non-free
        programs. This is because we decided to explicitly permit the
        use of the Bison standard parser program in Bison output files
        without restriction. We made the decision because there were
        other tools comparable to Bison which already permitted use
        for non-free programs.

So, the only possible grey areas with GNAT would be (a) if it copies
parts of itself into its output; or (b) statically or dynamically
links to GPL'ed libraries. In regard to libraries, we note in the case
of GCC:

    Does the libstdc++ exception permit dynamic linking?

        Yes. The intent of the exception is to allow people to compile
        proprietary software using gcc.


So, can anyone comment on whether (a) or (b) actually applies to GNAT?
I have my doubts that (a) would apply, since it doesn't seem to apply
to GCC. As for (b), that would be a matter of library licensing, and
not of GNAT's licence itself.

David


-- 

David Trudgett
http://www.zeta.org.au/~wpower/

All these men who were going to murder or to torture the famishing and
defenseless creatures who provide them their sustenance had the air of
men who knew very well that they were doing their duty, and some were
even proud, were "glorying" in what they were doing.

    -- Leo Tolstoy