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

[Gerard Vermeulen]

On Tue, 19 Apr 2005 15:28:44 -0400
Joe Harrington <jh at oobleck.astro.cornell.edu> wrote:

> > Can I legally distribute sqw.py separately under the BSD (or
> > some GPL compatible license)? 
> > So why should sqw.py be
> > > distributed as GPL code in the first place? 
> 
> > Some interpretations of copyright law (e.g. Larry Rosen's) say that no, 
> > it doesn't have to. The FSF's, Trolltech's, and Riverbank's say 
> > otherwise.
> 
> If FSF et al. really say this, they're dreaming.
> 
> Who says that the "Qt" library that it is going to be run with will be
> the one they know about?  There are numerous clone products that
> provide API-compatible functionality under different licenses, and in
> fact this is the main business of the FSF.  GNU really is Not Unix, in
> an IP sense, even though many of their program can be and frequently
> are compiled, linked, and run on UnixTM systems using native
> compilers and libraries.
> 
> There is a distinction to be drawn between two types of "modified
> code".  In the first instance, you take some source code from someone
> else and modify those actual lines of text.  In the second, your
> subclass *asks the compiler, linker, or interpreter* to modify or
> extend something that the compiler defined due to instructions from
> elsewhere.  The first case is certainly a derived work, and falls
> under the terms of the parent document.  You used someone else's IP to
> make something new.  GPL demands that you use GPL to license the
> derived work.
> 
> As I understand it, the second is not a derived work *in its source
> form*, because you didn't start with or include substantial sections
> of prose or code someone else wrote.

Let me point out that if you write
#include <qt.h>
you are including 2 MByte of code (those headers are copyrighted, so
they must be IP, isn't it?).
To me that is equivalent to telling your book printer to include a
chapter of a book written by somebody else in your book.  Now, if your
program falls in shatters by removing this single line, you cannot claim
that your program is no derived work.

PyQt hides this include statement for you and passes Qt's functionality
on to Python.  But does this really make a difference?

Gerard