On Tuesday 18 February 2003 05:21, david wrote: > Dear all, > > I don't understand the licence for qt and pyqt. On X11, it's GPL and on > Microsoft Windows, it's what ? Commercial licenses and a > free-as-in-free-beer for older version. That's very disorder ! > I have not a good idea for the future... > which choice pyqt or pygtk ? >
My understanding is that Qt is free on X11 as long as you are writing free software. Qt is not free if you want to write non-free software on X11. If you want to use Qt for windows, you need to pay no matter what. The confusion about the Windows version is because they recently changed their licensing with Windows when they released Qt 3.0. Here's a page that spells that out in more detail: http://www.trolltech.com/products/licensing.html As far as PyQt is concerned, Phil has a similar licensing scheme. You can read about it on this page. http://riverbankcomputing.co.uk/pyqt/index.php The reason why there is a license duality is because of the GPL. The free software version of Qt is licensed under the GPL, so if you want to use it, you have to agree to writing free software. This makes all the people who use Linux, and all the companies who put together distributions of linux happy. But this is bad because you cannot then sell software using the Microsoft model. The GPL intentionally prevents this. So Trolltech and Phil say "If you pay me, I will license my software under a different license for you". This makes everyone else who doesn't want to work the Linux way happy. So now you have a choice if you want to write Qt software on X11. You can either write Free Software, or you can try to make a money and write not-free software. Qt's opinion on Windows is that as soon as they make the windows source code licensed under the GPL or BSD or something like that, they will not produce any more software for it for free. I think it is because it is so hard to maintain code for Windows systems, but that is my opinion. -- Jonathan Gardner [EMAIL PROTECTED] Python Qt perl apache and linux _______________________________________________ PyKDE mailing list [EMAIL PROTECTED] http://mats.gmd.de/mailman/listinfo/pykde