The commercial qt license gives you the full rights to create and. On the qt website you can find obligations of the lgpl. Qt licensed under the gnu lesser general public license lgpl version 3 is. Moving to the issue of source publication, that is specifically, deliberately removed under lgpl lesser gpl, providing certain conditions are met. Do i have to buy a qt commercial license for developing an. Note for those looking for commercial pricing it is sort. In other words, if qt were lgpld, companies would not have to buy the professional edition in order to make commercial nonfree software, they could just. In such case, this license incorporates the limitation as if written in the body of this license.
Qt contains also thirdparty code that is licensed under specific opensource licenses from the original authors. Documentation contributions included herein are the s of their respective owners. The mobile phone giant is expected today to announce that qt 4. Qts lgpl license relates to qt and qt only, so you can package your code and license it however you like, but unless you plan on buying a qt commercial license, you have to dynamically link to qt. The third alternative is to go with the gpl license, which will require your product to meet the gpl2 or gpl3 terms. Qt to be available for free under lgpl successful software. It fails the debian free software guidelines, used by several linux distributions, though it qualifies for the free software foundations free software definition. The documentation provided herein is licensed under the terms of the gnu free documentation license version 1. As a special exception to the gnu lesser general public license version 2.
This license covers distribution of the software, use of thirdparty application programs based on the. Qt licensed under commercial licenses are appropriate for development of. For opensource licensed qt, some specific parts modules are not available under the gnu lgpl version 3, but under the gnu general public license gpl instead. The open source archive for the new model includes the lgpld qt 4.
The qt company gratefully acknowledges these and other contributions to qt. This license applies to any software containing a notice placed by the holder saying that it may be distributed under the terms of the qt noncommercial license version 1. The free software foundation may publish revised andor new versions of the gnu lesser general public license from time to time. Qt for application development is duallicensed under commercial and open source licenses. It was not published by the free software foundation, and does not legally state the distribution terms for documents that uses the gnu lgplonly the original english text of the gnu lgpl does that. The commercial qt license gives you the full rights to create and distribute software on your own terms without any open source license obligations. Qt tools and some libraries are only available under gpl. You can get a commercial license which allows you to do everything with qt with no concerns about opensource. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. Qt is available under lgplv3 so that half of the problem is solved. Qt licensed under commercial licenses is appropriate for development of. Most likely all developers were instructed to answer ianal, please contact our legal department.
In addition to the all os license terms supplied with the commercial release of qt 4. Is the version in the downloads section a lgpl version. Python examples of modern gui python programms grokbase. As qt for android uses the lgpl version of qt, and its perfectly possible and also recommended and supported to dynamically link in the qt libraries when creating an app there are no problems for app developers using qt for android. The lgpl is designed to permit developers of nonfree programs to use free libraries quote from the lgpl. So qtproject develops the open source version while digia develops the commercial one. The qt company ltd, valimotie 21, 00380 helsinki, finland. Why you shouldnt use the lesser gpl for your next library. The gnu lesser general public license lgpl is a freesoftware license published by the free software foundation fsf.
Development platforms and restrictions this certificate entitles a single developer to use the software for development on the following platforms. You can also make commercial apps using qt for free with the lgpl license. All other trademarks are property of their respective owners. Only users with topic management privileges can see it. See how to choose a license for your own work for general recommendations about choosing a license for your work the gnu project has two principal licenses to use for libraries. Why is qt not distributed under the gnu library general public license lgpl. However, we hope that this translation will help chinese.
The qt libraries are available under the gpl or lgpl license. In compliance with lgpl, this document collects the relevant information about downloading, installing, and building the. Qts commercial license is for when you wish to modify qts source code, and not release the changes you have made to the public. Gnu lesser general public license version 3 open source. Lgpl allows you to have a binary application, as long as it is dynamically in the sense of at runtime linked. Qt started off with a commercial license in 1995, adding gpl in 2000. Does still qt support lgpl license for future updates or is it commercial only now on. If you already started a project based on qt you need to be quick if. This is at least the stated goal of the qt company. The aim of this article is to clear up some of that uncertainty.
It is very dissapointing however to see absolutely no help from people who work in qt on the lgpl subject. But if you use some 3rdparty libraries which are not lgpl and instead gpl, then again there are some additional things you might need to do. Even modules like the virtual keyboard, the software renderer for qml without opengl and the unittest integration into qtcreator will become available under gpl. Qt licensed under our commercial license agreement is appropriate for development of proprietarycommercial software where you do not want. Also, theres nothing preventing you from selling an open source app on the microsoft app marketplace. You can use only those parts of qt that are under the lgpl and have no concerns about opensource. Qt for application development is also available under gpl and lgplv3 open source licenses. Gnu lesser general public license version 3, 29 june 2007 copyright c 2007 free software foundation, inc.
The older nontouchscreen model was apparently under 4. As long as you meet the requirements that gpl or lgpl impose on you, you have nothing to worry about. Lgpl which qt is released allows commercialclosed source applications as long as you do not modify the qt libraries or if you do making them available to the public. Revised versions of the gnu lesser general public license. Highend components and thermal solutions, made possible by our years of industry experience, provide better. Trolltech is perhaps the most successful free software company around and they have no shortage of commercial third party software companies that choose qt. Both licences allow the use of the library for commercial purpose. Qt licensed under the gnu lesser general public license lgpl version 3 is appropriate for the development of qt applications provided you can comply with the terms and conditions of the gnu lgpl version 3 or gnu gpl version 3. But the lack of an lgpl option is what arguably lead to the rise of gnomegtk when that project started in 1997, because its the lgpl that allows organizations to write closedsource proprietary software without paying a. The license allows developers and companies to use and integrate a software component released under the lgpl into their own even proprietary software without being required by the terms of a strong copyleft license to release the source code of their own components. The gpl makes sense for tools, as it ensures that anyone distributing a modified version gives the changes back to the community, but doesnt prevent using the tools to create nonfree software. Can i use qt lgpl license and sell my application without.
The desktop app i sell uses qt, against the lgpl license. The lgpl license allows an application that references the binaries to remain closedsource. Read the legal definition ofand proprietary, then go consult a lawyer. The lesser general public license lgpl is a software license that is based on the gpl, but is more permissive i have seen the gpl software license described as a cancer before, and this analogy does indeed hold, even though it misses the point. As i understand, you can buy a commercial license from qt and get commercial support, patches etc like we do in our company. The qt development tools and related applications like the qt creator ide will be released under the gplv3 as well as a commercial license. Since qt is being used under lgpl, they dont have to release code that calls it. Using the digia qt framework lgpl for commercial applications. Metallicow licensing pyside has been published as a response to the lack of suitably licensed qt bindings for python. The app developers can develop closed source code and publish the app. With the commercial license you also have access to the official qt support and close strategic relationship with the qt company to make sure your development goals are met. Such software is herein referred to as the software.
Thats not true of course, its lgpl licensed and so can be used for commercial software as long as the license obligations are adherred to. Can i use an lgpllicenced library in my commercial app. This is an unofficial translation of the lgpl free documentation license into chinese. Supply power to monstrous gaming rigs with our power supply units. Since your corporate application is for inhouse use only, you or more accurately, your company could license qt under the gpl for free. The free software foundation may publish revised andor new versions. As someone who works for a company that owns qt commercial for unix, id like to offer my point of view. Besides, it doesnt matter since kdelibs is lgpld, and therefore cant be linked with gpld qtx11. The legal department will tell you buy our commercial license, its the only option.