[Qt-interest] LGPL and static linking

[David Ching]

"Stefan Josefsson" <stefan.josefsson at vsmgroup.com> wrote in message 
news:OF16D52AEF.9AD88251-ONC1257679.003237C1-C1257679.003252F9 at vsmgroup.com...
> Hi,
>
>  I am planning to develop a commercial closed source application on top of 
> Qt/E and
>  would like to use Qt statically linked to my application as this gives a 
> substantial
>  boost to the startup time and also reduces the RAM usage. The question is 
> whether
>  I am allowed to use the LGPL license of Qt. I have read a number of 
> discussions about
>  LGPL and static linking
> ....
>

If Qt/E is the embedded Qt, I believe, in addition to determining what kind 
of linking is allowed under LPGL, there is the additional question of 
whether you must pay a royalty (per copy) license to Nokia.  I believe you 
must pay the royalty if your device requires Qt to perform its main 
function.  You do not have to pay if your device would continue to function 
(but with degraded functionality) without Qt.


> What is Nokias view of static linking and LGPL?
>

At the Qt Developer Days in San Francisco earlier this month, there were two 
excellent presentations by a woman from the legal counsel of Nokia Qt 
Development Frameworks.  She said within Nokia they explicitly prohibit 
static linking of their LPGL applications due to vagueness of the terms in 
the LPGL 2.1 wording.  She said the wording could be interpreted differently 
based on the jurisdiction, and the jurisdiction might be the one of the end 
user, not the one where the app developer (i.e. you) lives.  So unless you 
want to open yourself to the interpretation of law in whatever jurisdiction 
your end user lives, it is wise to stay away from static linking.  She 
recommended consulting your own attorney and said all she could do was to 
explain what Nokia themselves do.

-- David