Qt open source licensing changed

A new 'start-up' license has also been announced that will help small businesses that want to utilise Qt in commercial desktop and mobile applications.

The Qt ecosystem -- consisting of around one million software developers creating cross-platform applications, UIs, and devices in over 70 industries -- is built upon a dual licensing model. This model has now been updated to support the needs of modern application development and ensure the continued growth of Qt. In turn, Qt users will be able to better determine the need for commercial licensing and have clear understanding of open source obligations.

Qt open source licensing is based on the principles of the Free Software movement. To ensure the existence of open source Qt, The Qt Company and KDE Free Qt Foundation have updated the existing licensing agreement that guarantees the availability of Qt under open source licenses. The agreement with KDE Free Qt Foundation, which was established in 1998, now includes new licensing options and covers all of today’s ubiquitous desktop and mobile platforms.

Juha Varelius, CEO, The Qt Company, commented: “The open source community has been fundamental to the development of Qt and we want to ensure that developers who choose this route can continue to fully benefit from, and contribute to, advances in Qt. In order to achieve this, it is important to preserve investment in development with contributions from those using the framework commercially.”

Lydia Pintscher, President of KDE e.V., said, “Today Qt is an essential part of many products. With the updated agreement, we continue to ensure that Qt remains available for a long time to come on a wide variety of platforms. Today’s announcement not only safeguards the open source Qt community but also provides access to new functionality that has been developed within the commercial space."

New versions of Qt will be licensed under a commercial license, GPLv2, GPLv3, and LGPLv3, but no longer under LGPLv2.1. The updated open source licenses better ensure end user freedom when using open source licensed versions of Qt. LGPLv3 explicitly forbids the distribution of closed embedded devices. Distributing software under these terms includes a patent grant to all receivers of the software. Commercial Qt licensing removes these requirements and includes professional technical support from The Qt Company.

Along with the updated licensing scheme, The Qt Company will streamline the Qt product structure (starting with Qt 5.7) by providing many formerly closed Qt APIs and tools in the Open Source offering, as well. This will also open up these parts of Qt for contributions by the active open source Qt community. Consequently, all Qt users will enjoy improved quality and faster innovation of the Qt framework and tools. Existing commercial licensees will benefit from these improvements without changes to their product or licensing terms. Users who comply with open source obligations now have new features, such as charting, data visualisation, virtual keyboard and advanced profiling, available to them.

In addition to these product structure and licensing changes, The Qt Company will be providing a commercial licensing solution for small businesses with annual revenue less than $100K, which will make commercial Qt application development on desktop and mobile platforms more feasible. This “start-up” license, for full use of Qt for Application Development, will be introduced during Q1 2016.