Another tool I use has a similar dual licensing scenario. Cincom
VisualWorks Smalltalk has a free non-commercial version. It is intended
to be used to personal/educational development and not for creating
commercial applications. It is fully functional as is the case with Qt.
OTOH if you intend to use the product for commercial purposes you must
purchase the commercial version of the software. You can't learn how to
use, develop some test projects, etc.in the non-commercial version and
then turn around and purchase the commercial version if you are
satisfied and want to sell and distribute the final product. They are
totally separate and can't be combined.
Amos King wrote:
···
On 9/27/06, Tom Pollard <tomp@earthlink.net> wrote:
>
> On Sep 27, 2006, at 12:25 PM, Paul Lutus wrote:
> >> Well, let's put it this way: Qt is dual licensed, one is
> >> commercial,
> >> one is GPL. So it *is* free/open source software.
> >
> > I read this earlier and wondered about it. Can a company really
> > release
> > software under the GPL, but place restrictions on its use like "no
> > commercial applications"? Do they have that right? I thought the
> > entire
> > point of GPL was to make the source available to anyone, for any
> > purpose,
> > and the recipients would have the same rights and obligations as the
> > originator (like publishing their own source).
>
> Someone using your software under the GPL does not have the right to
> use it for any purpose.
>
> Releasing your software under the GPL does not impose any further
> obligations on you.
>
> As the author (or, copyright holder) of a piece of software, you can
> choose to release it under different licenses to different people.
> Choosing to release your software to someone under the GPL in no way
> restricts your right to release it under a more limited license to
> someone else, or to stop releasing later versions under the GPL at
> all. The GPL just restricts what someone using your software can
> legally do with it. It's still your software.
>
> (Waiting for someone to correct my overly broad assertions....)
>
> TomP
>
>I think Tom is entirely correct. I took an Intellectual Property Law
for Computer Science class and that is the same conclusion the
instructor(a patent lawyer and comp sci.) came to.Although QT has gone a little further. The libraries that are used
under the commercial license are slightly different. Really what
makes your product compiled with QT different is the libraries used to
compile(commercial or GPL). You can develop under the free version as
long as it never leaves your development enviroment in that fashion.
This includes demos of the software. Everything beyond the
development phase must be done with the commercial versions of the
libraries.I had first hand experience with this. A friend wanted to develop on
MAC, but wanted to deploy on Windows. I helped him do a lot of
calling and research with this. After talking to a lawyer and the
people at TrollTech, we found that as long as we didn't compile the
production versions on the MAC and as long as we didn't use the
non-production versions to demo to potential buyers we had not
violated any Licensing.Sorry about the tangent, but I thought it might help.
--
Amos King
USPS
Programmer/Analyst
St. Louis, MO