[FYI] QT4 licensing looks very bad for *BSD
cswiger at mac.com
Thu Jun 30 16:51:21 GMT 2005
Ted Mittelstaedt wrote:
[ ... ]
> The copyright laws govern this sort of thing not the GPL, and
> the courts have consistently held that a Copyright holder can
> pretty much do what they want, and can put any kind of licensing
> terms they want on something. In short a Copyright holders
> right to control how his work is used trumps anything else.
This generalization is correct, within certain important limits: a copyright
right holder can put pretty much any license terms they want onto something.
This generalization is also wrong: lots of licenses contain terms which are not
enforcable, and there exist considerations which trump copyright law. For
exmaple, if you write a program and distribute it under a license which says
that anyone who uses your software must kill Ted's mother-in-law, one would
discover that your mother-in-law's "right to life" trumps this license.
Plenty of licenses claim that the user "may only make one archival or backup
copy of the software". Fair use (here in the US) and data retention
requirements (here and elsewhere) permit people to take as many backups as they
need to. This sort of thing happens often enough that non-trivial software
licenses expect that some of their terms may be found to be unenforcable,
leading to clauses such as:
"If any portion of this section is held invalid or unenforceable under
any particular circumstance, the balance of the section is intended to
apply and the section as a whole is intended to apply in other
circumstances." (GPL clause #7)
[ ... ]
> Now, there IS one loophole in the Qt modified GPL license.
> That is, you could use a program like emacs to write a C++
> program that calls Qt classes. You could then distribute this
> program in source form, with a commercial or restrictive
> license, despite the fact that Trolltech's wording is:
> "By using this version of Qt/QSA, you agree to"
> and legally you would not be infringing.
Of course you could. In fact, you could even release a binary version of the
program which dynamicly loaded the Qt library if present, and still not be
infringing, so long as your code is seperate and independent of Qt.
This is precisely what the proprietary video drivers from ATI and nVidia for
Linux do. ATI and nVidia cannot redistribute a Linux kernel plus their
drivers, since that combination would violate GPL #7, but so long as they do
not redistribute GPL'ed code, they are not subject to the terms of the GPL.
> Any user that compiled your program with Qt would be infringing.
If the user compiled the program *and* redistributed a binary containing both
that software and Qt, it would be infringing. But if the end-user simply uses
the combination without redistributing it, then there is no infringement.
See GPL clause #0 just below (qv).
> However, if you used QtDesigner or any of that to write your C++ program,
> your source would be subject to the Qt license restrictions.
The output of a tool like an editor is generally not covered by the license
which applies to the tool itself:
"Activities other than copying, distribution and modification are not
covered by this License; they are outside its scope. The act of
running the Program is not restricted, and the output from the Program
is covered only if its contents constitute a work based on the
Program (independent of having been made by running the Program).
Whether that is true depends on what the Program does." (GPL #0)
Microsoft doesn't own the Word or Excel documents you might create using
Office, and TrollTech doesn't own the software you might create using QtDesigner.
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