Re: Autoconf Archive Licensing

[Francesco Salvestrini]

Hi all,

On Saturday 25 July 2009, Peter Simons wrote:
> Hi guys,
>
> Karl Berry is currently evaluating the archive for acceptance into the
> GNU project. He and Richard Stallman have brought up an issue with the
> licensing and I would appreciate your opinion on the matter.
>
> Macros that are licensed all-permissively put no limitation whatsoever
> on the licensing of the generated configure script. This is also true
> for the BSD license and for GPL+Autoconf-Exception. The LGPL, however,
> doesn't have that property. If a macro is licensed LGPL, then the
> generated configure script cannot be licensed, for instance, under the
> GPL, because GPL and LGPL are incompatible.
>
> Now, there are numerous macros in the archive that are licensed LGPL:
> <http://www.nongnu.org/autoconf-archive/macros-by-license.html>.
>
> RMS is worried because we distribute macros with a permissive license
> and LGPL macros all mixed up in one tarball. This creates a situation
> where it's easy for our users to rely on an LPGL macro without realizing
> what exactly that means, because they assume that all those macros are
> "free".

We could (maybe) soften the edges of the problem in one of the following ways:

1) Using an _AX_MACRO_LICENSE into each macro, e.g.:

  AC_DEFUN([AX_SOME_MACRO],[
    _AX_MACRO_LICENSE([LGPL2])
    ...

And a AX_PACKAGE_LICENSE macro into the user configure.ac:

  AX_PACKAGE_LICENSE([GPL3])

The AX_PACKAGE_LICENSE could do license checking for the user (AC_MSG_ERROR 
for a bad mix).

Those checks are going to be performed each time configure runs but they could 
be so easy to be irrilevant compared to all the operations performed into an 
usual configure script.

2) Enhancing the LICENSE tag as 'LICENSE <LICENSE>' into each file, e.g:

#
# LICENSE LGPL3
#

Since the distribution is autoconfiscated, we could have an --enable-lgpl that 
selectively installs macros into the user system (using the tag to perform 
the task).

> To remedy the situation, we could distribute LGPL macros in a separate
> tarball.

I would prefer to not have different tarballs but I've no strong points 
against that at the moment than the personal preference.

My 2nd point could avoid those different tarballs, maybe.

> We could also try to avoid that by convincing the respective macro
> authors to re-license their work under A-P, GPL+AC, or BSD.

I would do that anyway.

Have a good day,
Francesco

-- 
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the earliest class.