My python programs need a GUI, wxPython or PyQt4?

[Giovanni Bajo]

On 24/01/2007 1.45, Joshua J. Kugler wrote:

>> I've downloaded both the wxPython and the PyQt4 package, and by the
>> first impression I must say that the PyQt4 system had a very
>> compelling presentation. From what I can understand from the feedback
>> I've gotten so far is that the wxPython is a better choice when it
>> comes to compability (with linux), and it's free even if I want to
>> create applications and sell them.
>> So, from what I understand I will have to go with PyQt4 since (from
>> my understanding):
>> 1. I will not sell the applications I'm working with since they will
>> only be used by the internal QA at a computer game company.
> 
> Even that is getting on shaky ground, at least according to Troll Tech. 
> See: http://www.trolltech.com/developer/knowledgebase/190/  So, write it
> for internal use, and put up for distribution on your personal web site
> (pending company approval, of course).

That page is legal babble, trying to trick you into buying (or making your 
boss buy) a commercial license. The Qt Open Source edition *IS* GPL and thus 
it falls under all the normal GPL clauses and uses, irrespective of what 
Trolltech may or may not think.

For instance, see this FAQ:
http://www.gnu.org/licenses/gpl-faq.html#GPLRequireSourcePostedPublic

which makes pretty clear that a "company"/"organization" is basically the same 
of an "individual". "Releasing a software within a company for internal usage" 
is by no means the same of "releasing it to the public". Basically, for what 
the GPL is concerned, it is *not* a "release" or a "distribution" at all.

Thus, it is well possible to write internal GPL software, using the Qt Open 
Source library, and to release/distribute/use it *ONLY* internally. Also, it 
should be made clear that a company can of course relicense its own 
proprietary libraries as GPL for internal usage only, so that they can be 
linked to other GPL libraries "legally". For instance, in the case of Daniel 
and his game company, they can link their proprietary game code to PyQt4 (Open 
source edition) to produce an internal tool, like a level editor, which would 
then fall under the GPL. If and only if they were to release that tool to the 
public (either for free or for sale), they would have to either go GPL and 
release full source code (include the parts of their game code linked to it), 
or buy a Qt commercial license.

[[ Another page of similar babble is the one where they try to convince you 
that you cannot use the Qt Open Source edition to develop a software, and then 
buy the commercial edition only the day before you want to release it as non 
open-source. I can't even understand how they can even try to support such a 
nonsense position. You're free to develop your software for years as GPL 
without distributing it, and then relicense your own code whenever you want. 
They're obviously just trying to scare people. ]]
-- 
Giovanni Bajo