Re: libxml? (was: Re: XML and GNOME community)

[Gleef <gleef capital net>]

On Sun, 7 Jun 1998 nuke@bayside.net wrote:
> On Sat, 6 Jun 1998, robert havoc pennington wrote:
> > On Sat, 6 Jun 1998 nuke@bayside.net wrote:
> > > well, there are quite a few GPL programs that use Qt and Motif, and the
> > > FSF hasn't sued yet. 
> > 
> > That's because they don't own the copyright. AFAIK so far all the GPL
> > programs using Qt were written by the same people that decided to use Qt,
> > and they can't sue themselves. Try linking a FSF-owned program with Qt and
> > you're taking a risk.
> 
> well then, shouldn't GPL programs linked to a NPL library be ok for the
> same reason? they wouldn't be owned by the FSF. (at least, that could be
> avoided)

On one hand, playing games like linking to Qt dilutes the license, and
makes it harder for the FSF or the independant GPL developers to use
lawsuits to defend their code.  On the other hand, I don't think that
this applies here.

Looking over GPL v2.0 (the one GNOME is using), and NPL v1.0, the only
problem I see with including NPL code in GNOME is the annoyance of having
to distribute both licenses, and the confusion of a developer trying
to figure out which pieces fall under which licenses.

GPL, in section 3 (3a is where I'm quoting, but 3b and 3c are analagous)
provides that:

	"You may copy and distribute the Program ... in object or
	 executable form ... provided that you also ... accompany it with
	 the complete corresponding machine readable source code, which
	 must be distributed under the terms of Sections 1 and 2 above."

Which means that, rather than requiring that all the source code to a GPL
program be distributed under GPL, it merely requires that the terms of
software redistribution match those in sections 1 and 2 in the GPL.  Qt
clearly violates section 2.  NPL, on the other hand, looks like it works 
with both of these these, but it might be worth a call to Netscape's
lawyers to get a real legal opinion.

NPL, in section 3.7, states that:
	"You may create a Larger Work by combining Covered Code with other
	 code not governed by the terms of this License and distribute the
	 Larger Work as a single product. In such a case, You must make
	 sure the requirements of this License are fulfilled for the
	 Covered Code."

This tells me that, provided that you drag along a copy of the NPL, all
the relevant copyright notices and Exhibit A, it doesn't mind being mixed
with other licenses.

So, basically, it looks to me that, as long as the Program is GPL, and the
included source is NPL, the two licenses are compatible as long as all
the required files are included. The other way around, of course, doesn't
work, since NPL requires contributions to be NPL licensed, and GPL doesn't
allow license switches without explicit written permission from the
author.

-Gleef