Re: GPLv3

[John W. Eaton]

On 14-Sep-2007, Shai Ayal wrote:

| Do we need all the libraries we link to to be GPLv3 compatible?
| Isn't it just the libraries we distribute that need to be compatible?

I think the libraries we link to need to have compatible licenses,
whether we distribute them or not.

Others have brought up the interface issues of things like the BLAS
and LAPACK, and in that case I think it doesn't matter so much except
that there must be some library that implements the interface (most
likely in a serious way, not just a bunch of stubs that say "sorry,
not implemented!) that can be used and has a compatible license.  But
even then, if you were to distribute a binary of Octave such that it
could only be used with MKL (statically linked, for example) then I
think that would not meet the requirements of the GPL, even though MKL
is just one of many libraries that implements the interface.

| In the graphics section I will be adding:
| freetype which has a BSD like license which shouldn't be a problem,
| fltk which is LGPLv2 with some restrictions lifted -- this could be a problem.
| FTGL - BSD like or LGPLv2
| gl2ps - GPLv2 or later

LGPLv2, even without the "any later version" clause is OK if all we
are doing is using a library and not borrowing portions of the code.
See the compatibility chart on the GPL FAQ page.  Note that there are
two sections to the chart, and upgrading to LGPLv3 is only needed in
the "borrowing code" section of the chart, not in the "using a
library" section.

| URW fonts - GPLv2 for whatever that means for fonts

OK, I'm not sure about fonts, so we will probably have to ask about
that.  Does the statement for the font files include the "any later
version" clause?

Thanks,

jwe