Licensing issues with dbus and dbus-glib

Christian F.K. Schaller uraeus at
Thu May 31 10:23:06 PDT 2007

On Thu, 2007-05-31 at 18:57 +0200, Thiago Macieira wrote:
> Christian F.K. Schaller wrote:
> >Of course the 'truth' in the context of contract interpretation is
> > defined by common perception and I guess a good litmus test to this
> > understanding would be if KDE for instance came out and said that now
> > that Qt is part of the LSB it is to be considered a system library and
> > thus there is no need anymore to pay TrollTech to develop closed source
> > Qt applications for Linux. If that ends up uncontested by TrollTech it
> > would set a mighty precedent.
> Sorry, but I do not think this example is valid.
> The GPL allows you to link to GPL-incompatible components if they are 
> considered part of the system. Even if we accept the hypothesis is Qt 
> part of the system, closed source applications are hardly so. So, a 
> GPL'ed Qt wouldn't be allowed to link to a closed-source application.
> The example would be valid if Qt were licensed under GPL-incompatible 
> licenses only (like the QPL or commercial licenses) and you wanted to 
> link a GPL application to it.
I stand corrected, I re-read the GPL2 (and 3) and I am not sure how I
had managed to conclude that GPL 'system libraries' could link to
non-GPL compatible apps, my bad.

> Disclaimer: I used to work for Trolltech.
> >Personally I prefer not to rely on system library clause for anything
> > not specifically listed in the GPL which for the GPL3 means glibc and
> > xlib as that is the only way currently to not get your lawyers into
> > panick mode.
> Same here. That was just a random thought.
> Even if we considered libdbus-1 a system library on Linux, I think it 
> would hardly be so in other systems, especially MacOS X and Windows. (The 
> other Unixes might be more accommodating).


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