Q Public License
The Q Public License is a software license for free software or open source. It was produced by company Trolltech and is known by the product Qt.
The license should grant the freedom of exchange of the software within the meaning of open source, similar to the familiar GNU General Public License ( GPL). She is certified by the Open Source Initiative, which one has more confidence that QPL - licensed software is open source.
The QPL is generally not compatible with the GPL, as you may spread clearly marked changes of QPL - licensed software only in the form of patches or similar. The GPL theoretically disallow the connection ( linking) of QPL software with GPL software, but some rights holders such as the Free Software Foundation grant special permits for this.
Rights
You may copy software that is released under the QPL, in unchanged form and pass it as long as you let untouched the package - that is, copyright notices, trade marks and disclaimers must be given, so as specified by the manufacturer. This ensures the integrity of the original version.
The software may be changed, and these changes may also be used, but only in a separate code from the original form, such as patches. However, other forms are not prohibited by the license, you can make your changes and otherwise clearly marked. Excluded from changes are a copyright notice. This strict separation of original and change is underlined.
Published developers the source code of its changes to QPL - licensed software, even under the QPL (which he does not have ), the author of the original version will have the right to involve these changes in a future version, as long as this future for this version again the QPL selected. This helps the developer of the original work of other developers, which was made possible by the openness of the source code for their personal benefit, but only if he re- releases it to the developer community.
In a publication of the changes in binary version of the developer must consider some points. On the one hand he must release the changes under the QPL license, on the other hand it must ensure that the users of their rights are clear have ( by enclose the license text ) and access to the source code. But he can not ask for more than the cost of the transfer, and it must clearly note the availability of the code in its changes. This is very similar to the GNU General Public License, which also ensures that binary code to the source code is always available. This passage also prevents changes to QPL - licensed software are simply placed under a different, perhaps paid license.
Like most Free Software licenses granted this right to the full use of the original or modified version together with other software and individually.
To connect with other programs ( "left" ) the QPL provides that the linked software must be free software. In this case, it means that the user of the linked software must obtain the source code more than the price of the transfer and the linked software changes are allowed, again with permission Redistributions in binary and source form to any person. If the linked programs or the source code is not open to the public, the developer of the original software may require that he be given a copy of the source code. In this way, the code can be released but then, as all who are in possession of a linked program may pass on this.
Disclaimer
The QPL excludes any liability of the developer for damages in any case completely, even if he was aware of deficiencies.
In addition, no warranty is given, the software and license are delivered "as is".
Jurisdiction of the QPL is Norway, the Oslo City Court as the court stated. So far, the license but has never had to be defended in court.
History
The Q Public License arose from the competition of the two Linux desktop environments K Desktop Environment and Gnome.
KDE uses Qt library for the graphical representation. Until 1998, Qt was a purely proprietary product, which in 1998 to the creation of the GNOME desktop led to not be dependent on one company.
However, with version 2.0 changed the license Trolltech Qt at the urging of the Free Software Foundation - Qt was released under the QPL. In order for the free development was ensured. For commercial products, there was an additional license. Only by this license change, it was possible for most Linux distributions, which include K Desktop Environment in their package list.
In April 1998, the responsibility of the QPL, and thus the right to change them to the KDE Free Qt Foundation was ceded. Thus, the freedom of Qt was ensured because the foundation may, Trolltech should not continue to exist as a company, or set the development of Qt and are the last version under the BSD license.
With version 4.5, Qt was made in March 2009 under the less restrictive LGPL.
Popular projects under the QPL
- Qt - Library and others for creating graphical user interfaces for various operating systems
- Cervisia - CVS frontend for KDE