Qt Everywhere: 4.5 To Be Relicensed As LGPL

Nokia has announced that starting with version 4.5, Qt will be available under the LGPL 2.1. From the announcement,

The move to LGPL licensing will provide open source and commercial developers with more permissive licensing than GPL and so increase flexibility for developers. In addition, Qt source code repositories will be made publicly available and will encourage contributions from desktop and embedded developer communities. With these changes, developers will be able to actively drive the evolution of the Qt framework.

This exciting change, made with consultation of the KDE Free Qt Foundation, should encourage KDE and Qt use among commercial and proprietary developers and makes the philosophy of "Qt Everywhere" complete.Kai ?ist?m?, Executive Vice President of Devices at Nokia expands,

"By opening Qt’s licensing model and encouraging more contributions, Qt users will have more of a stake in the development of Qt, which will in turn encourage wider adoption."

The change in licensing for Qt is happening under the mantra "Qt Everywhere" and is a step to remove any and all possible blocking objections for not using Qt. Nokia explains further,

Qt will be available under the LGPL version 2.1 with the upcoming Qt 4.5 release. Qt will also continue to be licensed under commercial license terms, as well as the GPL, version 3.0.

Nokia will also be opening up the development of Qt. A clear path for the extension of external contributions is currently being built, including publicly available source code repositories and access to the same level of support, independent of the license.

The simple fact behind this is that Nokia is less reliant on the income from Qt licensing than Trolltech (now Qt Software) was, and this has given Qt Software more room to approach the market with more permissive licensing strategies in order to increase adoption of the Qt toolkit. This is part of the 10x growth target announced at last year's Akademy to achieve ten times as many developers and ten times as many free software community users. Or as KDE and Qt developer Thiago Maciera put it "we want KDE to be ten times as big".

While kdelibs has always been available under the LGPL, this marks the first time that both Qt and kdelibs will both be available under the LGPL. This will help make the licensing of KDE's libraries more permissive, flexible and coherent. KDE's licensing is summarised on TechBase, and can be described as "LGPL or equivalent for libraries, GPL otherwise".

Meanwhile, Nokia reiterates their commitment to a commercially viable and, technology-wise, best-of-breed toolkit. In fact, the performance and functionality improvements that can be seen in the upcoming Qt 4.5 release are impressive. Running KDE 4.2 with Qt 4.5 is already being tested by several engineers inside Qt software, which has resulted in a number of bug fixes in both KDE and Qt. Independent of the licensing changes, the KDE release team plans to update the version of Qt in KDE's development tree (qt-copy) shortly to snapshots of Qt 4.5 which is due to be released in March.

All-in-all today's news means tremendous things for Free and Open Source software. The possibility of extending the reach of all of our work is exciting in and of itself, and this announcement could lead to a veritable explosion of Qt and KDE adoption.

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