Re: [Off-topic] Licenses (Was: How to reratify the DFSG ?)
Rev. Joseph Carter <knghtbrd@earthlink.net> wrote:
> > It's not because Qt is not GPL -- BSD is not GPL, and you can link GPL'd
> > code with BSD code. The problem is that if you linked GPL'd code with
> > Qt code then distributed the result as the GPL specifies Troll-Tech (or
> > whoever owns the license at the time) could sue you, and would probably
> > win.
>
> Qt's license says the program must be GPL or similar to use Qt free.
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.
> This is where the restriction is made that source code be available for
> everything. It says that source code need not be provided for that which is
> normally distributed with the OS. Some use the argument that Qt is a
> standard library and therefore meets this exception. Most don't buy that.
Certainly, Debian doesn't include Qt in the stuff that's supposed to be
installed for a "standard" system.
> If distribution of executable or object code is made by offering access
> to copy from a designated place, then offering equivalent access to
> copy the source code from the same place counts as distribution of the
> source code, even though third parties are not compelled to copy the
> source along with the object code.
>
> I don't know about you, but I read this paragraph as "if you don't package
> all source code used in the program, out can have the source code available
> in a designated place and we'll call it good enough." You can get source to
> Qt free, but there are restrictions to using it that are different from
> those of the GPL.
This isn't the central issue, but it is relevant.
If you send your binaries out on cdrom, then you'd have to offer to
send out the qt sources on cdrom too.
But, if you're using qt, you can't even send out the binaries on cdrom
in some cases.
> This is not clear. It does not say that the separate package need be
> GPL as well. The above paragraph doesn't even say that included source
> code must all be freely modifyable, only that it must be included. I
> would say it is inferred from other paragraphs that the software must
> also be GPLed.
You're inferring wrong. You must be able to distribute the other sources
with the gpl'd source, but it's perfectly permissible to have your own
license on those sources, and nowhere does it require you to use a
modified version of the GPL. The X license is an example of a license
which is not the GPL which allows the sources to be distributed with
the GPL'd sources.
> So, once again: Mozilla is not GPL, neither is Qt. Both have source
> available to the requirement of this license. So, why is GPL code
> using Qt bad, but GPL code using Mozilla not? I say the problem is
> clearly a political one, not a legal one.
Because Qt has restrictions on distribution of binaries.
> His license doesn't back him up. (Please point out the relevant part if I
> am wrong, it's not a simple 2 screen document after all)
It's not his license that's the issue, it's Qt's. Here's an excerpt
from the Qt license:
You may also use the Qt toolkit to create reusable components (such as
libraries) provided that you accept the terms above, and in addition that:
- Your components' documentation includes the following text:
[Your package] requires the Qt library, which is copyright
Troll Tech AS. Freely distributable programs may generally
use Qt for free, see [README.QT] for details.
- README.QT is distributed along with your components.
- Qt is not distributed as an integral part of your components.
Also, note that nothing permits you do distribute code based on Qt
where someone else wrote the code. For example, nothing in Qt's license
permits you to link emacs with Qt and distribute that. For you to
distribute an application linked with Qt, you have to have written it,
or the program's author must have written it for use with Qt -- I can
spell out the terms in Qt's license which specify this, if you like.
[There's some silly reporting requirements, but in my opinion that's
all they are: silly. At least in the US they're not enforceable because
copyright affects distribution, not application. Also, you can't force
someone to become a free software distributor.]
--
Raul
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