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About Trolltech QT OpenSource license.

Hi to all,

i am coming from the Microsoft (.net) world and at the quest of
finding the right GUI toolkit that i can use from Python, i have two
obvious choices to choose from: wxPython and Qt.

Both are looking very good. Qt has Qt designer, a tool that really
reminds me of the forms designers that we have in VS.Net.The
productivity someone can gain from tools like these can be really
astonished.
I saw at the forum here that a lot of debate is coming from the
"strange" interpretation of it's Open Source Edition lisence.
After a lot of reading i was under the impression (and many others
with me) that even a stand alone developer working in-house at company
cannot use Qt OS Edition and must buy the commercial lisence.

I sent an emai to them today and i think their response is
interesting, so i appose it here;

############### ############### ############### ########
Thank you for your inquiry regarding the Qt Open Source Edition.

The open source edition may be used for either your own private use or
for an application used only internally by your company if the
application is developed by you on company time. With internal
company use under the GPL it is absolutely imperative that the
application not be distributed outside of the legal entity. If this
happens then the GPL source distribution requirements (as well as all
other GPL
requirements) will take effect. The internal use by the company falls
under the "private modification" exception to the GPL.

Please note that if you begin your application development with the
GPL version, that application must be GPL licensed and Trolltech does
not permit developers to start with the Qt Open Source Edition and
later convert to a commercial license.

Good luck with your development and please contact sa***@trolltech .com
if your company wishes to purchase a commercial Qt license at some
point in the future.

Apr 10 '07 #1
21 1862
king kikapu napisa≥(a):
I saw at the forum here that a lot of debate is coming from the
"strange" interpretation of it's Open Source Edition lisence.
After a lot of reading i was under the impression (and many others
with me) that even a stand alone developer working in-house at company
cannot use Qt OS Edition and must buy the commercial lisence.
This is a bullsh*t. Qt is free (as in "free speech") on GPL. Nothing
stops you from using it in any commercial project if only it fits the
licensing terms (i.o.w. it's free software). This specially applies to
inhouse development, as in such case there's no "distributi on".
I sent an emai to them today and i think their response is
interesting, so i appose it here;

############### ############### ############### ########
Thank you for your inquiry regarding the Qt Open Source Edition.

The open source edition may be used for either your own private use or
for an application used only internally by your company if the
application is developed by you on company time. With internal
company use under the GPL it is absolutely imperative that the
application not be distributed outside of the legal entity. If this
happens then the GPL source distribution requirements (as well as all
other GPL
requirements) will take effect. The internal use by the company falls
under the "private modification" exception to the GPL.

Please note that if you begin your application development with the
GPL version, that application must be GPL licensed and Trolltech does
not permit developers to start with the Qt Open Source Edition and
later convert to a commercial license.

Good luck with your development and please contact sa***@trolltech .com
if your company wishes to purchase a commercial Qt license at some
point in the future.
Hey, there's no such statement here. Where did you get this "must buy
the commercial lisence"?

Plus, this (sales)person forgot to state clearly, that GPL covers only
distribution, not the cost of software. If you manage to get some hot
cash for selling sources of your GPL-ed program, the license would not
try to stop you from doing that. ;)

--
Jarek Zgoda
http://jpa.berlios.de/
Apr 10 '07 #2

Ō/« Jarek Zgoda ›„ŮŠÝŚ:
king kikapu napisa≥(a):

This is a bullsh*t. Qt is free (as in "free speech") on GPL. Nothing
stops you from using it in any commercial project if only it fits the
licensing terms (i.o.w. it's free software). This specially applies to
inhouse development, as in such case there's no "distributi on".
Hmmm...how a commercial software (that means i get paid for give it)
it will be consider "free software" ?
I ask because i surely do not understand correctly the GPL lisence and
all that stuff.
Hey, there's no such statement here. Where did you get this "must buy
the commercial lisence"?
Good point! I got it because at the last portion of my email, i asked
for it. I asked them that:
"And in the case i want to build something that i want to later sell
(as an individual)..."

so i got it back.

Plus, this (sales)person forgot to state clearly, that GPL covers only
distribution, not the cost of software. If you manage to get some hot
cash for selling sources of your GPL-ed program, the license would not
try to stop you from doing that. ;)
As i said, i do not fully understand all this license stuff. All i
want to ask is, i can make GPL software and gain money from this ? And
if that so, then why they "force" you to buy the commercial lisence in
such case ?

Apr 10 '07 #3
king kikapu wrote:
As i said, i do not fully understand all this license stuff. All i
want to ask is, i can make GPL software and gain money from this ?
Yes. Nothing in the GPL prevents you from developing and marketing an
application for as high a price as you can get from it.

HOWEVER:

you will have to distribute the source code to your application to
anyone who purchases a binary from you.

AND:

they will be permitted under the GPL to redistribute your application,
source code and all. The GPL would allow them to buy your application
from you and then redistribute it at no cost to others.

Most commercial shrink-wrap software depends on enforcing restrictions
on end users to compel a revenue stream: withholding some of the
application's functionality prior to payment, hiding the locking
algorithm inside obfuscated source code, and prohibiting modification
and redistribution of the application and/or its code. If this is your
business model, then the GPL is probably not for you.

If you use the GPL, you would have to make your locking alogrithim as
plain as day; someone out there would likely have the knowledge to patch
your software to work without the locking algorithm, assuming they
obtained the binary and source code legally (either by purchasing it
from you or obtaining it from someone who purchased it from you); and
they would be legally free to redistribute the patched application, with
or without cost.

Of course, there's no guarantee this will happen; such patching also
happens with closed-source software. But many commercial developers look
at the GPL and decide that this is a risk they do not want to take.

--Kevin

--
Kevin Walzer
Code by Kevin
http://www.codebykevin.com
Apr 10 '07 #4
king kikapu napisa≥(a):
>This is a bullsh*t. Qt is free (as in "free speech") on GPL. Nothing
stops you from using it in any commercial project if only it fits the
licensing terms (i.o.w. it's free software). This specially applies to
inhouse development, as in such case there's no "distributi on".

Hmmm...how a commercial software (that means i get paid for give it)
it will be consider "free software" ?
I ask because i surely do not understand correctly the GPL lisence and
all that stuff.
The GPL is about distribution of software. If you provide your program
with sources and allow redistribution under provisions of GPL, it will
be free (as you provide some "freedoms" listed in the license
statement), even if you earn cash for it. It's "free as in freedom" (or
free speech), not as in "free beer". Please, contact your local FSF,
CreativeCommons or ISOC lawyer to get an advice if you feel you need a
lawyer's assistance. For the brief explanation of the problem, see
http://www.gnu.org/philosophy/selling.html. This document should cover
most cases. ;)
>Plus, this (sales)person forgot to state clearly, that GPL covers only
distribution , not the cost of software. If you manage to get some hot
cash for selling sources of your GPL-ed program, the license would not
try to stop you from doing that. ;)

As i said, i do not fully understand all this license stuff. All i
want to ask is, i can make GPL software and gain money from this ? And
if that so, then why they "force" you to buy the commercial lisence in
such case ?
They cann't and the don't. If you obey GPL rules, you're right. The
(sales)person you had a conversation with is, well, just a salesperson.
Trolltech makes money from selling commercial licenses, so these persons
will always try to persuade you to buying a license or two, "just in
case". ;)

--
Jarek Zgoda
http://jpa.berlios.de/
Apr 10 '07 #5
On 10 Apr 2007 12:29:36 -0700, king kikapu <ab********@pan afonet.grwrote:
Hi to all,

i am coming from the Microsoft (.net) world and at the quest of
finding the right GUI toolkit that i can use from Python, i have two
obvious choices to choose from: wxPython and Qt.

Both are looking very good. Qt has Qt designer, a tool that really
reminds me of the forms designers that we have in VS.Net.The
productivity someone can gain from tools like these can be really
astonished.
There is another alternative: Dabo, which wraps the wxPython toolkit.
It has a GUI designer, although not as polished as the Qt Designer.
Check out some of their screencasts to see their tools in action. You
can find them at http://dabodev.com/documentation

--

# p.d.
Apr 10 '07 #6

Ō/« Peter Decker ›„ŮŠÝŚ:
There is another alternative: Dabo, which wraps the wxPython toolkit.
It has a GUI designer, although not as polished as the Qt Designer.
Check out some of their screencasts to see their tools in action. You
can find them at http://dabodev.com/documentation
I am aware but i prefer to use PythonCard if i choose wxPython over
Qt. I think Dadbo has a lot of work to be done, it is surely very
promising, thanks!
@ Kevin and Jarek :
thanks for the enlightening of that GPL thing. So, if i understand, i
create my Python software using Qt as my GUI, i earn the money for it
with the obligation to release my source code and somewhere in my
files i explicilty write that this software is under the GPL lisence,
is that correct ?? And i am legal all the way out ??

So why these people at Trolltech have the word "Commercial " at their
mouth all the time ?? I can understand of course that money is all
about but becauce they released Qt under GPL they simply cannot
prevent anyone from gaining money using it.

Apr 10 '07 #7
king kikapu wrote:
>

@ Kevin and Jarek :
thanks for the enlightening of that GPL thing. So, if i understand, i
create my Python software using Qt as my GUI, i earn the money for it
with the obligation to release my source code and somewhere in my
files i explicilty write that this software is under the GPL lisence,
is that correct ?? And i am legal all the way out ??
That's correct, as far as I know. (IANAL)
>
So why these people at Trolltech have the word "Commercial " at their
mouth all the time ?? I can understand of course that money is all
about but becauce they released Qt under GPL they simply cannot
prevent anyone from gaining money using it.
In this case, "commercial " == "proprietar y" == "closed-source." If your
source is released in complicance with the GPL, you don't have to buy a
license from Trolltech.

--
Kevin Walzer
Code by Kevin
http://www.codebykevin.com
Apr 10 '07 #8
@ Kevin and Jarek :
thanks for the enlightening of that GPL thing. So, if i understand, i
create my Python software using Qt as my GUI, i earn the money for it
with the obligation to release my source code and somewhere in my
files i explicilty write that this software is under the GPL lisence,
is that correct ?? And i am legal all the way out ??
This is correct... but you should also understand the GPL license aswell.
So why these people at Trolltech have the word "Commercial " at their
mouth all the time ?? I can understand of course that money is all
about but becauce they released Qt under GPL they simply cannot
prevent anyone from gaining money using it.
That is a mistake, the oposite of libre software is non-libre or
proprietary.
--
damjan
Apr 10 '07 #9
king kikapu wrote:
As i said, i do not fully understand all this license stuff. All i
want to ask is, i can make GPL software and gain money from this ? And
if that so, then why they "force" you to buy the commercial lisence in
such case ?
Others have given good answers. I would only like to clarify what I think is the
source of confusion here. While the FSF and many open source advocates make a
distinction between the words "commercial " (meaning that someone derives money
from distributing the software, whether it is GPLed or not) and "proprietar y"
(meaning that the software is not being distributed under an open source license
but one that restricts user's rights), Trolltech abuses the term "commercial " to
mean "proprietar y" in this case.

If you obey the terms of the GPL and still manage to derive money from it, you
don't need Trolltech's "commercial " license. Just be sure that you do obey the
terms of the GPL; it's not entirely trivial to build a business model around it.
Such a business will be somewhat different from one that uses proprietary licenses.

--
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
that is made terrible by our own mad attempt to interpret it as though it had
an underlying truth."
-- Umberto Eco

Apr 11 '07 #10

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