[SciPy-user] Re[2]: ANN: Veusz 0.5 - a scientific plotting package

[Gerard Vermeulen]

On Mon, 18 Apr 2005 21:53:45 -0700
Robert Kern <rkern at ucsd.edu> wrote:

> Robert Kern wrote:
> > Gerard Vermeulen wrote:
> 
> >> If you do not use commercial licensed releases of PyQt and Qt, you
> >> are using the GPL versions.  This implies that you have to release
> >> your software based on PyQt also under the GPL license.
> >>
> >> The modified BSD being compatible with the GPL does not mean that
> >> you can release GPL derived works under the BSD license.
> > 
> > 
> > The work as a whole must be distributed under the terms of the GPL. 
> > However, Jeremy's code can be under whatever license he wishes as long 
> > as it is compatible with the GPL. If he chose the modified BSD license, 
> > one could take pieces of that code, inasmuch as they are separable from 
> > PyQt, and incorporate them into matplotlib. Just because the 
> > BSD-licensed code is combined with GPL-licensed code doesn't mean that 
> > the BSD-licensed code is not BSD-licensed.
>  >
>  > Or if he feels like avoiding this silliness, Jeremy could, if he
>  > wanted to, just separately license the bits that other people want to
>  > use in BSDish-licensed, non-PyQt projects.
> 
> C.f. http://www.opensource.org/licenses/gpl-license.php
> Section 2
> 
> """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. But when you 
> distribute the same sections as part of a whole which is a work based on 
> the Program, the distribution of the whole must be on the terms of this 
> License, whose permissions for other licensees extend to the entire 
> whole, and thus to each and every part regardless of who wrote it.
> """
>

If you write a Python script for PyQt you do not modify PyQt or Qt,
but you use it.

The intent of the GPL is clarified in the GPL-FAQ. Here
http://www.gnu.org/licenses/gpl-faq.html#IfLibraryIsGPL
applies:

"""If a library is released under the GPL (not the LGPL), does that
mean that any program which uses it has to be under the GPL?

Yes, because the program as it is actually run includes the library.
"""

The business model of Trolltech which also sells commercial licenses
for Qt is based on this answer.

Gerard