• 1. Introduction to Qt

    Qt is a software development framework with ready-made libaries and tools. Value of Qt is the speed and ease of development regardless of underlying platform.

    Qt is dual-licensed under either commercial or open source licenses. Qt is developed by the Qt project with open governance model. The biggest contributor and IPR owner of the Qt is The Qt Company.

    In order to develop and distribute your product with Qt, you must adhere to obligations and definitions enforced by either the commercial or the open source licensing.

  • 1.1. Who actually owns and controls Qt?

    Qt trademarks and most of the copyrights are fully owned and controlled by The Qt Company. The development work for Qt toolkit is done through the open source governed Qt project by The Qt Company R&D and external Qt contributors. The Qt project is an open ecosystem and infrastructure for developers and companies to contribute to Qt. All external contributions are licensed to the Qt company allowing re-licensing under both open source and commercial terms.

    The Qt Company has a binding agreement with KDE Free Qt Foundation to ensure the availability of Qt under certain open source licenses for desktop and mobile platforms. The open source community and availability of Qt is an extremely important part of the whole value proposition of Qt, and something The Qt Company wants to commit to and drive forward.

  • 1.2. What are the licensing options for the Qt framework?

    The Qt development framework and tools are available either under commercial or open source license.  

    The commercial licenses of the Qt framework include additional features not available under open source license, technical support, and immediate access to all releases. The commercial license options for the Qt framework and development tools are:

    • Qt for Application Development (AD) license: a license for those creating Applications used in generic desktop and mobile environments. 
    • Qt for Device Creation (DC) license: a license targeted at developers creating Applications and/or Devices, for example dedicated or embedded devices, embedded systems, and other digital hardware products.   

    The Qt development framework and tools can also be used under open source licenses, mainly GPLv3 and LGPLv3. The open source licenses require you comply to the open source terms and conditions. Different parts of the Qt framework and development tools are available under a variety of open source license types including LGPLv2.1, GPLv3, LGPLv3, BSD, or MIT. Please check the documentation of the individual component for further information on its open source licensing terms.