Using PyQT under the MIT license?

[Jim Tilander]

Hi all,

So after a little bit of digging I saw that Qt itself allows for some
other open source licenses
(http://doc.trolltech.com/4.4/license-gpl-exceptions.html) including
MIT License, which is my favourite no nonsense license. I'm
maintaining a couple of open source python scripts under the MIT
license and was toying with the idea of adding a user friendly GUI to
them, Qt and PyQT are looking pretty good since Tkinter is ugly and
almost all the other toolkits just fails abysmally under Win64
environments. Now I ran into a little bit of a snag, I can not find a
similar exception list to the GPL license for PyQT as for Qt itself.
The only thing I did find was
http://www.riverbankcomputing.co.uk/static/Docs/PyQt4/pyqt4ref.html#license
... except the wording "If you use the GPL versions then your own code
must also use a compatible license." could be interpreted either way,
compatible with GPL, or compatible with the license for Qt itself,
which *does* allow for MIT license. Oh how I hate licenses...

Could anyone clarify what that last sentence refers to? I want to
interpret it as it's free for the MIT license, but of course I'm
slightly biased.

Cheers,
/j

[Phil Thompson]

Post by Jim Tilander
Hi all,
So after a little bit of digging I saw that Qt itself allows for some
other open source licenses
(http://doc.trolltech.com/4.4/license-gpl-exceptions.html) including
MIT License, which is my favourite no nonsense license. I'm
maintaining a couple of open source python scripts under the MIT
license and was toying with the idea of adding a user friendly GUI to
them, Qt and PyQT are looking pretty good since Tkinter is ugly and
almost all the other toolkits just fails abysmally under Win64
environments. Now I ran into a little bit of a snag, I can not find a
similar exception list to the GPL license for PyQT as for Qt itself.
The only thing I did find was

http://www.riverbankcomputing.co.uk/static/Docs/PyQt4/pyqt4ref.html#license

Post by Jim Tilander
... except the wording "If you use the GPL versions then your own code
must also use a compatible license." could be interpreted either way,
compatible with GPL, or compatible with the license for Qt itself,
which *does* allow for MIT license. Oh how I hate licenses...
Could anyone clarify what that last sentence refers to? I want to
interpret it as it's free for the MIT license, but of course I'm
slightly biased.

PyQt has the same GPL exceptions as Qt does. Note that even if you use a
license covered by those exceptions you have to accept additional GPL-style
restrictions.

Phil

[Simon Hibbs]

Hi all, I just joined the mailing list although I've been browsing the
archives occasionally for quite some time.

I already hold a PyQT3 license through owning a copy of Blackadder, the now
basically defunct Python/QT IDE from TheKompany. There's no way i could
conceivably afford a full commercial QT3 license for my extremely modest
purposes, but Blackadder gave a cheap way to get a QT3/PyQT3 license for
only a little more than a PyQT3 license on it's own. Blackadder itself is
old, clunky and largely non-functional but I only bought it for the
licenses.

I am in negotiations for a small programming job, it's a spare-time project
for me and I only expect to make one or two thousand pounds out of it at
most. I will very happily cough up for a commercial PyQT4 license if the
project goes ahead because I'm doing it for the fun of it not realy the
money and PyQT will make the job easier and more fun to do.

Having said all that, there are still a number of reasons why I would love
to see PyQT4 go the LGPL route. One of the main ones is that I would like to
be able to offer the option of user-written scripts for this project. That's
not possible for a commercial PyQT project because that makes all the users
developers. In this specific case I can work around it by offering some
customization through config files, but it's still a significant limitation
and it's unusual to be in a situation where a free application can actualy
have a significant feature that a commercial version couldn't have - paying
money to get less, in a way.

Simon Hibbs