[Qt-interest] Help understanding the move to LGPL

[Scott Aron Bloom]

> -----Original Message-----
> From: qt-interest-bounces at trolltech.com [mailto:qt-interest-
> bounces at trolltech.com] On Behalf Of Justin Noel
> Sent: Thursday, January 15, 2009 8:49 AM
> To: qt-interest at trolltech.com
> Subject: Re: [Qt-interest] Help understanding the move to LGPL
> 
> 
> IANAL (I Am Not A Lawyer), but here are the generalities:
> 
> > Please redirect me if this is off topic.
> >
> > Given : an application written using the open source distro of Qt
4.5
> >
> > Question: Do I have to release the source ?   I have seen info that
says I
> do not.
> >
> 
> You do not have to distribute the source for you applications given
that your
> application is compatible for use with LGPL libraries. You have to
make sure
> that the end user can replace your version of the LGPL library with
their own
> and your app will still work. Compliance can simply be to dynamically
link
> against Qt.
> 
> You can read the entire LGPL 2.1 licence here:
> http://www.gnu.org/licenses/lgpl-2.1.txt Also, ICS has a new
whitepaper
> detailing the simple steps to making sure your application (or
> libraries) are compatible with LGPL libraries. The whitepaper is
located
> here: http://www.ics.com/files/docs/Qt_LGPL.pdf on http://www.ics.com.
> > Question: Am I permitted to charge for it ?  I have seen info that
leads me
> to believe that I am allowed to.
> >
> 
> You can charge as much as you like for your application. The LGPL
states that
> you can have whatever license you want for your application as long as
you
> make available the version of the LGPL'd libraries to your customers
including
> any changes you make to the LGPL'd library itself.
> If you are using a stock Qt version from Trolltech's website you could
provide
> something like a mycompany.com/opensource which links to Qt Software's
site
> and list your opensource page in your application's documentation.
> 
> Good Luck!
> --Justin

I think the best way to look at what Nokia is doing, is putting the QT
libraries in the same league as the Lib C system.

There are copyright requirements, as in you must say Portions of the
Application are copyright Nokia etc etc...  but as long as you are not
modifying the QT system, its free to use.

Again, until QT releases the final license doc, we don't know all the
details... But this is a MAJOR MAJOR gain for QT

Scott