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Re: [Off-topic] Licenses (Was: How to reratify the DFSG ?)

Rev. Joseph Carter <knghtbrd@earthlink.net> wrote:
> > > Qt's license says the program must be GPL or similar to use Qt free.

> On Sat, May 30, 1998 at 09:42:18AM -0400, Raul Miller wrote:
> > That's not all it says.  If I were to use Qt to develop an enhanced
> > version of GTK, and distributed the result under the terms of the GPL,
> > Troll Tech (or whoever bought them) could sue my pants off.

Rev. Joseph Carter <knghtbrd@earthlink.net> wrote:
> You -COULD- write a GTK-compatible wrapper for Qt. You could even
> use the GTK source for it (this would not be worthwhile, but) and
> you could even distribute the results as GPL software. However, the
> Qt library must remain unchanged. Therefore the code is not freely
> modifyable. As I said, there was nothing in the GPL which requires
> that the code by modifyable, only that it be present. Nobody could sue
> you for this, and in fact the Troll people would prolly be happy to
> see that a Qt version of gimp is possible.

Even if that weren't a problem for the GPL it would be a problem for
Debian, because we couldn't fix bugs.  However, take a look at this
paragraph from the GPL:

    6. Each time you redistribute the Program (or any work based on
  the Program), the recipient automatically receives a license from
  the original licensor to copy, distribute or modify the Program
  subject to these terms and conditions. You may not impose any further
  restrictions on the recipients' exercise of the rights granted herein.
  You are not responsible for enforcing compliance by third parties to
  this License.

What are you going to do when you distribute GTk linked with Qt, and
someone modifies Qt?  You would have granted them the right to modify the
program, but you wouldn't have had the right to do so.

Another issue for GTk is that you couldn't ship working binaries,
because you can't ship Qt as an integral part of GTk.

> You can distribute Qt source/bin libs as long as you don't change them.

Not if it's a part of some other components you're building.

> KDE has not violated the Qt license and they have now afaict violated the
> GPL by releasing KDE as GPL software.  My question remains:  How can it be
> illegal for KDE to be GPL software because if its use of Qt?

KDE isn't GPL'd software, you can't distribute it under terms where
whoever you distribute it to can modify any part and redistribute the
resulting binaries. So you can't legally distribute it the terms of the
GPL. [But, of course, it can be distributed under other terms.]

> Are you saying then that the issue is one of clarity rather than of
> what the license means? If that is all that is the problem, there is
> a very simple fix to the matter and I am certain Troll Tech would
> be happy to clarify their license considering the impact it would
> have. I'm sure it's not good PR for them to have RMS saying that GPL
> software using Qt free is illegal.

It could be.

In the free world authors retain control of the interfaces they build by
offering superior systems, not by legal action.  But an essential concept
is that the user controls the interfaces they're using.  [Breaking the
interface has rather nasty consequences at upgrade time, and that's 
penalty enough.]

> Of course, changes to the license are not allowed directly by Troll Tech
> anymore--but that's fine considering the Free Qt group would undoubtedly
> support this bit of clarification.

Depending on whether they wanted Qt to be free software.

> Also, you pointed out lawsuit if someone buys Troll Tech.  Not gonna happen. 
> If anyone buys Troll Tech, the license to Qt free becomes BSD license so
> Troll Tech's new owners cannot try to Qt free and software based on it in
> this manner.

Well that's an interesting concept. It's not a part of the license,
however, so I doubt it's legally binding.


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