I'd like them to release Qt under the GPL (GNU's General Public Licence), possibly with additional permission to dynamically link with software produced under the Qt Professional Edition licences, Artistic Licence or whatever.
Here is the petition [ http://www.rustcorp.com/petition/petition.html ], which has been delayed due to a flurry of new entries in the last couple of days. Current target is between Christmas and New Year.
The GPL is not compatible with the QPL (see FAQ). This means that the KDE project [ http://www.kde.org ] still have to get additional permission from all their authors to link with the Qt library. It also means that they can't KDE-ize entire apps without doing the same thing, or reuse existing code (eg. GNU Ghostscript, GNU Plot, Electric Eyes, etc.). Debian and RedHat are becoming increasingly strict about licences, and they wouldn't distribute such problematic binaries.
The greatest benefit of releasing Qt under the GPL is that it reduces the barriers for code sharing between KDE and Gnome [ http://www.gnome.org ] apps (see FAQ). Having two or more open-source desktops compete on merit is a Good Thing, but stealing each others code in large or small lubricates the evolution of both.
The GPL is also my personal preferred licence, and I don't want to create problems for someone wanting to create a Qt GUI for something I write.
I've found the Trolls to be enlightened people; it's the details which bit them in the past. I wouldn't want that to happen again if I can help.
Name (1 line, eg. Paul `Rusty' Russell) EMail (1 line,eg. firstname.lastname@example.org, Rusty.Russell@rustcorp.com.au) Bio (1 line, eg. Linux Kernel IP Firewall Maintainer) Comment (multi line; I may include some, none or all in the final petition)
Plus, noone else was doing it.
KDE apps cannot reuse Gnome code in other ways, nor can an existing Gnome app be KDE-ized, since these apps are generally GPL (not LGPL).
Thanks to David for this clarification, and I apologize if people found my previous misleading statement, er.... misleading.
A number of people have asked me why the QPL licence is incompatible with the GPL, when the X11 and zlib licences apparently are compatible (as far as linking with these libraries goes). The X11 distribution terms are so permissive that they let you add just about any license you prefer, when you make a derivative or combined work. In particular, you could add the GPL. Thus, when you combine Xlib and some GPL-covered program, the combination can be distributed as a whole under the GPL. The QPL doesn't allow this; you cannot include Qt in a combination which is covered by the GPL.Thanks RMS.
Rick Macdonald suggested I clarify as follows:
TrollTech makes money by charging for the right to use the Qt Professional
Edition in proprietary products, and for support. The QPL is designed to
protect their sales of the Professional Edition. The GPL also disallows
such use, and therefore offers the same protection. It is a feasible
option for TrollTech to use the GPL.
My proposal is "GPL, possibly with additional permission to dynamically link with software produced under the Qt Professional Edition licences". The second part is important for Troll.