Re: ReRegarding iraf

[Glenn Maynard <glenn@zewt.org>]

On Mon, Jan 10, 2005 at 11:21:24AM -0500, Justin Pryzby wrote:
> IRAF has a kind of custom government license which was previously
> decided [0] to be free.  IRAF wants to link with NCAR which is (now)
> available under the GPL.  Is that allowed, even though IRAF is not
> GPL?  IRAF is not a "derivitive" of NCAR, although the resulting
> executable binaries would be, I guess.  GPL seems to say so:

You can always link GPL material with non-GPL material, so long as that
other work is GPL-compatible.  The question is whether IRAF's license is
GPL-compatible.  You'd be better off asking the FSF about that.  I believe
it is.  The only clause that gives me any pause is:

  "that references to the Association of Universities for Research in Astronomy
  Inc. (AURA), the National Optical Astronomy Observatories (NOAO), or the Image
  Reduction and Analysis Facility (IRAF) not be used in advertising or publicity
  pertaining to distribution of the software without specific, written prior
  permission from NOAO"

This is similar to the BSD license's "name of the author may not be used
to endorse or promote products derived from this software", but is more
broad (you can't use the name at all, even in ways that don't endorse or
promote the product; for example, you can't even acknowledge their
contributions), and it applies to organizations, not people.  I doubt
it's a problem.

>   These requirements apply to the modified work as a whole.  If
>   identifiable sections of that work are not derived from the Program,
>   and can be reasonably considered independent and separate works in
>   themselves, then this License, and its terms, do not apply to those
>   sections when you distribute them as separate works.
>   [...]

This only means that combining (eg. via shared or static linking) GPL
code with other code does not render that other code GPL-licensed.  (I
think this clause is really a no-op: if sections aren't derived from the
Program, then the GPL has no say over it, anyway--this just makes that
fact explicit).  Binaries are subject to the GPL's terms, but the separable
code remains under its own license, which is still available if that code
is excised.

> If that is the case, then it seems that I should consider creating a
> complementary NCAR package ("when you distribute them as separate
> works"), on which IRAF would have build and runtime dependencies (I
> don't know if the upstream NCAR build intends for the libraries to be
> shared .so files, or if they even intend for the libraries to be
> installed on a runtime-only system, but no matter).

There's no need to split them up if you wouldn't otherwise.  That's not
what the above clause is talking about.

-- 
Glenn Maynard