[Mono-dev] C bindings VS C++ bindings (Gtk# vs. Kimono?)

Jonathan Pryor jonpryor at vt.edu
Wed Sep 26 16:35:09 EDT 2007

On Wed, 2007-09-26 at 20:37 +0100, James Mansion wrote:
> The use of GPL is very unfortunate - Qt does at least allow for MPL and 
> an extending range of other
> open source licences.  

Uh, Qt is NOT compatible with MPL and an extended range of other open
source licenses.  From [0], you have an effective choice between a
commercial license (which would permit any license for your code that
you care for, permitted you pay for a Qt license *before* you begin
development) and the open source licensing [1] which requires you to use

Oddly, it appears that [1] doesn't even require GPL-*compatible*
licensing, but the GPL by name:

        The Open Source Edition is freely available for the development
        of Open Source software governed by the GNU General Public
        License (GPL version 2)
        If you wish to use the Qt Open Source Edition, you must
        contribute all your source code to the open source community in
        accordance with the GPL when your application is distributed.

This could be interpreted to mean no MIT-X11/BSD/LGPL programs...

(Or you could use Qt under the QPL license -- I'm not sure what it can
be linked against -- but the QPL isn't used for the Win32 or OS X ports
of Qt, which would decimate any "platform portability" arguments you may

In short, Qyoto *is* the same license as Qt, unless you want Qyoto to be
dual-licensed in the same manner that Qt is (which would be odd as afaik
Qyoto is NOT developed by TrollTech).  So the best you could hope for is
for Qyoto to use LGPL, but apps still wouldn't have a choice of licenses
unless they paid TrollTech $$$.

(Though really, the Qyoto site [2] should spell this out; I can't find
any mention of licensing on their web site.)

In short, if you don't want to GPL your apps you should stick to Gtk# or

 - Jon

[0] http://trolltech.com/products/qt/licenses/licensing
[1] http://trolltech.com/products/qt/licenses/licensing/opensource
[2] http://cougarpc.net/qyoto/

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