[svlug] Linux GUI license question

[Brian J. Tarricone]

On 09/19/04 12:49, Wang Xiangzhou wrote:
> Hi,
> 
> I am developing a home entertainment appliances on Linux. When I come
> to select GUI tool, I am confused with som many choice and their
> license.
> 
> I can open source the project, but when distribute as commercial
> software, will it cause license issue if I use GPL software? (Qt for
> example)

if you are linking with a GPLed GUI toolkit, your code must be GPL (and thus
open source) as well.  you won't be able to release a proprietary version.

> So would someone recommend which Linux GUI tool is good, no licensing
> fee for commercial distribution.

disclaimer:  i'm not a lawyer.  you should probably talk to one if you're
unsure about this type of stuff.  having said that...

qt is released under a dual license.  for free/non-commercial/opensource
projects, qt is licensed under the GPL.  however, if you want to create a
proprietary app that uses qt, you need to buy the "commerical edition" from
trolltech.  i suggest you look at their FAQ:
http://www.trolltech.com/developer/faqs/license_gpl.html

gtk (http://gtk.org/) is licensed under the LGPL, which, simply put, means
that you can write a proprietary closed source app using it, as long as you
dynamically link with gtk (or provide object files for your application so it
can be relinked, but that's much less common).

if you're interested in portability, you might consider wxwidgets
(http://wxwidgets.org/, formerly called wxwindows).  it uses native widgets
on windows, unix/linux (using gtk2), and i believe mac os x as well.  it
has a license similar to the LGPL, which again means that you can
distribute closed source apps linked to it if you so desire.  gtk2 works on
windows as well, but, from my experience, it's often unstable and tends to
eat resources.

hope tihs helps.

	-brian