I corrected a couple of factual errors in the licensing of KDE and GNOME LGPL in fact does not allow any license as it restricts reverse engineering see section 6 of the LGPL Also the GPL does not impose restrictions on the KDE libs and apps as some are under licences allowed by the QPL and most are already GPL compatible The most important consequence is that you need to buy a license to develop proprietary software with Qt hence I added it Also Qt was already available under the QPL before being GPL d so I try to make that more clear