Author Publisher Trolltech AS DFSG compatible No | Latest version 1.0 Published 1999–2000 FSF approved Yes | |
The Q Public License (QPL) is a non-copyleft license, created by Trolltech for its free edition of the Qt. It was used until Qt 3.0, as Trolltech toolkit version 4.0 was released under GPL version 2.
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It fails the Debian Free Software Guidelines, used by several Linux distributions, though it qualifies for the Free Software Foundation's Free Software Definition; however, it is not compatible with the FSF's GNU General Public License, meaning that products derived from code under both the GPL and the QPL cannot be redistributed.
History
KDE, a desktop environment for Linux, is based on Qt. Only the personal edition of Qt was covered by the QPL; the commercial edition, which is functionally equal, is under a pay-per-use license and could not be freely distributed. Meanwhile, the Free Software Foundation and authors of the GPL objected to the QPL as it was a non-copyleft license incompatible with the GPL. As KDE grew in popularity, the free software community urged Trolltech to put Qt under a license (the QPL) that would assure that it would remain free software forever and could be used and developed by commercial third parties. Eventually, under pressure, Trolltech dual-licensed Qt for use under the terms of the GPL or the QPL.
Adoption
Other projects that have adopted the Q Public License, sometimes with a change in the choice of jurisdiction clause, include:
Previous projects using the Q Public License include:
The Debian project rejects software covered by solely QPL (and not dual licensed with something else like the GPL) because of:
Compliance
All legal disputes about the license are settled in Oslo, Norway, but it has never been legally contested.