Re: What if Guile changed its license to be LGPL?

[Per Bothner]

Marius Vollmer wrote:
> The special license of Guile means that we can't use other LGPLed
> software for it without putting the whole of Guile under the LGPL,
> effectively.

I don't believe that is the case.  There is no conflict between
the LGPL and the Guile GPL+exception license.

The real problem is that it makes it difficult to distribute a
a proprietary executable that includes a statically linked
copy of GMP.  In contrast, the existing Guile license allows
you to distribute a proprietary executable that includes a statically
linked copy of Guile.

For most people this is not an issue:  They can link against
a shared library version of libgmp.  (I see that Red Hat 7.3
comes with such a shared library.)  The main problem is for
people on embedded systems.  They are unlikely to be using
Guile, or if they use Guile, they are unlikely to want bignums.

So I don't think it's a real problem.  My suggestion:
(1) Keep the Guile license as is.
(2) Add a --with-gmp configure option.  It defaults to true if
it finds a shared library version of libgmp; false otherwise.
(3) If --with-gmp is "no", use floating-point numbers instead
of bignums.  (Actually, embedded systems might not want floating
point either, but that is a separate issue.)

You might (if you haven't already) ask RMS about modifying the GMP
license to GPL+exception, at least in the context of Guile.  (I would
also love to be able to use GMP for libgcj, the GCJ Java urn-time
library, when implementing java.lang.math.)
--
        --Per Bothner
address@hidden   http://www.bothner.com/per/