Qt is available under different licensing options designed to accommodate the needs of our various users:
- Qt licensed under commercial licenses is appropriate for development of proprietary/commercial software where you do not want to share any source code with third parties or otherwise cannot comply with the terms of the GNU LGPL version 3.
- Qt licensed under the GNU Lesser General Public License (LGPL) version 3 is appropriate for the development of Qt applications provided you can comply with the terms and conditions of the GNU LGPL version 3 (or GNU GPL version 3).
Qt contains also third-party code that is licensed under specific open-source licenses from the original authors.
Note: For open-source licensed Qt, some specific parts (modules) are not available under the GNU LGPL version 3, but under the GNU General Public License (GPL) instead. See the list of Qt modules for details. For commercial licensees, all modules are available under a single, commercial Qt license.
Qt documentation is licensed under the terms of the GNU Free Documentation License (FDL) version 1.3, as published by the Free Software Foundation. Alternatively, you may use the documentation in accordance with the terms contained in a written agreement between you and The Qt Company.
See http://qt.io/licensing/ for an overview of Qt licensing.
Purchasing and Sales Information
To purchase a Qt license, visit http://www.qt.io/download/.
For further information and assistance about Qt licensing, contact our sales; see http://www.qt.io/locations/ for contact details.
Licensed Code in Qt
The following page documents the open-source licenses used in different parts of Qt:
© 2018 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.