Before you begin, make the right license choice.
Qt for Application Development is dual-licensed under commercial and open source licenses. The commercial Qt license gives you the full rights to create and distribute software on your own terms without any open source license obligations. With the commercial license you also have access to the official Qt Support and close strategic relationship with The Qt Company to make sure your development goals are met.
Qt for Application Development is also available under GPL and LGPLv3 open source licenses. Qt tools and some libraries are only available under GPL. See the comparison chart for details. The Qt open source licensing is ideal for use cases such as open source projects with open source distribution, student/academic purposes, hobby projects, internal research projects without external distribution, or other projects where all (L)GPL obligations can be met.
For more information, please see the FAQ.
With Qt for Device Creation, you can create embedded devices with modern UIs with maximum performance. In addition to Qt APIs, it comes with a full embedded tooling suite built around the Qt Creator IDE, and additional embedded solutions that help you reduce your time-to-market dramatically.
Qt for Device Creation is a product available only under a commercial license. This allows you to, for example, control your device’s user experience, and build proprietary functionality on top of Qt and to lock down your device. A commercial license from The Qt Company keeps your code proprietary where only you can control and monetize on your end product’s development, user experience and distribution.
In addition to creating individual applications or devices, Qt can also be used to create full software platforms and the Qt developer offering can be extended for a custom distributable SDK. In this case, the Qt licensee is not just using Qt libraries and tools for their own software/distribution but actually distributing a Qt-based SDK to a number of software developers that then become users of Qt libraries/tools themselves. For this purpose, we provide a custom SDK licensing option.
In order to preserve the true meaning of open development and uphold the spirit of free software, it is imperative that the rules and regulations of open source licenses required by the Free Software Foundation are followed. Learn more: http://www.gnu.org/licenses.
When deciding which license to use, please check your corporate open source policy or consult a SW licensing legal expert.