Qt tightens open-source licenses

The Qt Company has changed the licenses it supports on the open-source versions of its user-interface software framework, putting a greater onus on users to feed the changes they make to the community.

The changes cover the software provided by the Qt Company and the KDE Free Qt Foundation and include new licensing options and covers the current mainstream desktop and mobile platforms.

Open-source versions of Qt will be licensed under a commercial license, GPLv2, GPLv3, and LGPLv3, but no longer under LGPLv2.1. The LGPLv3 license explicitly forbids the distribution of closed embedded devices – where providers forbid downstream users to use and adapt the source code. Distributing software under these terms includes a patent grant to all receivers of the software.

To support companies that want to protect IP they develop that involve changes and modifications to the framework code, Qt will continue it policy of offering commercial licenses that remove the free-software obligations. The commercial licenses includes professional technical support from company.

To support smaller companies earning revenues of less than $100,000 that want to keep modifications to themselves, Qt has introduced a new “start-up” license.

Juha Varelius, The Qt Company CEO, said: “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.”

Together 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. The features include charting, data visualization, virtual keyboard, and advanced profiling.