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Qt General Faq
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| What is Trolltech? | |
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Trolltech is an international software company with headquarters in Oslo, the capital of Norway, and with offices in Brisbane, Australia, and Santa Clara, California. Our flagship product is Qt, the multi-platform C++ GUI toolkit. Trolltech AS was founded in 1994. However, the core team of designers at Trolltech started developing Qt already in 1992. Ever since then, Qt has steadily expanded and improved. Qt is currently used in thousands of software development projects world wide. | |
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| Is there a graphical designer/dialog builder for Qt? | |
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Yes, we offer the Qt Designer. | |
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| Is there a mailing list or something for Qt? | |
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There are several: You can find descriptions and instructions for joining them, and an archive of messages here. | |
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| I think I have found a bug in Qt. Where can I report it? | |
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Please report to qt-bugs@trolltech.com. Remember to include the version number of Qt, and the make and version of your compiler and your operating system. | |
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| Is the Reference Documentation available in printed form? | |
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No. | |
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| Is the Reference Documentation available in PDF format? | |
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No, we prefer HTML for online-browsing. The HTML format documentation is included in the Qt source archive, so you can browse it off your local disk, you don't need to access www.trolltech.com. Open the file qt/doc/html/index.html with your favorite web browser. | |
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| What kind of licenses exist for Qt? | |
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The Qt toolkit is available under two different licenses: The Professional and Enterprise Editions for commercial use on all platforms, and the Free Edition for developing free/open source software for the X11 platform. | |
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| What are the differences between the Professional/Enterprise Editions and Free Edition of Qt? | |
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You may write commercial/proprietary/non-free software only if you have purchased the Professional or Enterprise Edition. The library itself is the same. With the commercial editions, you also get technical support and upgrades. Qt for Microsoft Windows and Qt for Mac OS X are only available as Professional and Enterprise Editions. | |
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| Can we use the Free Edition while developing our non-free application and then purchase commercial licenses when we start to sell it? | |
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No. The Free Edition license applies to the development phase - anything developed without Professional or Enterprise Edition licenses must be released as free/open source software. | |
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| When will version x.y be released? Will it include so-and-so feature? | |
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We try not to make public speculations about the whats and whens of the next Qt release, because we do not want to be known as a vaporware company. | |
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| Are there any books about Qt programming? | |
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Yes, several. They are listed here. | |
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| Is there an evaluation version of Qt for Windows so I can try it out before purchasing? | |
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Yes, see details here. | |
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| I don't want to give away my source code. What do I do? | |
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Then you need a Professional or Enterprise Edition license. | |
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| What tool do you use to create the Reference Documentation? Where can I get it? | |
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The documentation generator we use is an internal tool. We recommend that you investigate the Doxygen program, a free tool specifically designed to be used for projects that make use of the Qt toolkit. Doxygen offers functionality very similar to our internal tool, and can link to the Qt documentation. For more information about Doxygen, visit the Doxygen home page. Note that Doxygen is an independent project not supported by Trolltech. | |
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| Can I charge for my application? | |
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If you have a Professional or Enterprise Edition license: Yes, of course. If you use the Free Edition your software must be freely redistributable and you must include the source. The Free Edition is intended for free software. We realize that CD-ROMs cost money to produce, for example, so you may charge a copying fee. | |
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| Where can I find Qt Free Edition? | |
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The latest version of Qt Free Edition can be downloaded from http://www.trolltech.com or from ftp.trolltech.com, and a whole range of ftp mirror sites around the world. Look for a mirror near you on the list available under http://www.trolltech.com/download/ We encourage all developers of free Qt software to upload their work to ftp.trolltech.com. | |
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| I want to port Qt to a new platform. What do I do? | |
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If the new platform is POSIX-like and runs the X Window System, it's simple. Read the file PORTING for details. | |
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| Can I make a Qt shared library and distribute it with my Linux distribution? | |
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Yes. | |
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| I found this obscure bug and I need it fixed, fast! | |
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Qt Professional and Enterprise Editions includes technical support service. We try to support the developers using the Qt Free Edition as well, and we take all bug reports seriously, no matter who they come from. But, of course, when there's too much to do, our customers have higher priority. | |
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| How would you compare Qt with Java? | |
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We believe Qt to be the superiour solution for most development tasks, not least for performance and portability reasons. Ref:
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Can I develop commercial applications with PerlQt or PyQt or other Qt wrappers? | |
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Yes, if you have purchased a Qt Professional or Enterprise license. The licensing conditions are the same whether you use the Qt API directly in C++, or you use it through some API wrapper in another programming language. This means that all developers that write code containing calls to the Qt API (directly or through a wrapper) require Qt licenses. | |
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We have purchased a license, but the developer is leaving the company / project. Can we transfer the license to another developer? | |
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Yes. Qt licences are for individual use to named developers. If the original developer using a licence leaves the organization, or moves on to another project not involving Qt, another developer can take over the licence. You can change the name of the developer using a licence at any time, but after a change you must wait at least six (6) months before changing again. You can only have one designated user for a licence at any given time. It is important that you notify Trolltech about changes in designated licence users at sales@trolltech.comWe need this information in order to give licence holders the best possible support. | |
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Can I purchase floating licenses for Qt Professional or Enterprise Edition? | |
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No, we do not offer floating licenses. The reason is this: Floating licenses are based on the concept of defining a maximum number of concurrent users. For example, for a word processor, this means the maximum number of instances of that application that can be running at any time. However, for a library product like Qt, there is no main application that is always running when the product is being used. Hence, it is not possible to count the number of concurrent users, and therefore floating licenses does not make sense. | |
