There's a GPL implementation of Motif available. There isn't one of Qt
(yet)

On Wed, 15 Apr 1998, Matthew Asplund wrote:

> 
> On Tue, 14 Apr 1998, Richard Stallman wrote:
> 
> > After reading the distribution terms for "FreeQT", I can see that they
> > are the same as formerly used for Qt.  In other words, "FreeQT" is a
> > misleading name: it is not free software.
> > 
> > The main problem is in this restriction:
> > 
> >        Nobody but Troll Tech ( the makers of QT ) are allowed to distribute
> >       modified versions ( they will and incorporate modifications however )
> > 
> > This restriction means that "FreeQT" is not free software, because the
> > freedom to distribute a modified version is a crucial aspect of what
> > free software means.  As a result, linking "FreeQt" with GPL-covered
> > programs violates the GNU GPL.
> > 
> Maybe this has been said before, but I will say it again.  RMS's arguments
> are unchanged if we substitute Motif for Qt.  I can get the Motif sources,
> and change them, but I cannot redistribute them.  In spite of this there
> is plenty of Motif GPL software out there.  I think of Qt as being the
> same class of software as Motif and therefore a perfect replacement for
> what Motif does on other UNIX desktops.   Is RMS willing to say that no
> GPL code can be linked with Motif?  Now that TOG has changed the X11
> licensing, is he willing to say that no GPL code can be linked to X11R6.5
> (or whatever the next version is?)
> 
> Matthew Asplund
> matt@xenon.cchem.berkeley.edu
>