Frequently Asked Questions

This documentation can be downloaded in full
This documentation can be downloaded in full

  1. Who is Troll Tech?

    Troll Tech is a company based in Oslo, the capital of Norway. Our business idea is to develop and market our multi-platform, superior quality, GUI toolkit: Qt.

    Troll Tech AS was founded in 1994. However, the core team of designers at Troll Tech started developing Qt already in 1992. Ever since then, Qt has steadily expanded and improved. Qt is currently used in hundreds of software development projects world wide.

    In addition to Qt development and support, Troll Tech engages on a consultancy basis in a large-scale software development project. The project, which naturally is based on Qt, is run by the Norwegian division of NCR (previously AT&T).

  2. Do you have any plans for a graphical designer/dialog builder?

    We are working on one now. There will be further announcements on qt-interest and, as appropriate, qt-announce.

    There is also a free dialog editor written by Jeff Harris and Klaus Ebner. See for more information.

  3. Is there a mailing list or something for Qt?

    There are two: and qt-announce.

    Qt-interest is a user forum. There can be as much as 20 messages per week. To join it, send a message containing the single word "subscribe" to

    Qt-announce is for announcements of new Qt versions and a few other announcements. We expect that there will be less than ten messages to the list each year. To join the list, send mail containing the single word "subscribe" to

    All messages to Qt-announce are also sent to Qt-interest, so you don't need to be on both lists.

  4. Can I use Qt's classes without writing a graphical user interface?

    Quite a few of the classes can be used independently of the user interface. See utility classes, for example. There are also a few classes that will work without the GUI only by chance.

  5. What kind of licenses exist for Qt?

    The Qt toolkit is available under two different licenses: The professional license for commercial use, and the free license for developing free software for the X platform.

  6. What are the differences between the professional and free licenses of Qt?

    You can write commercial software only if you have professional license(s). The library itself is the same. You also get one year of free support and upgrades when you buy professional license(s).

  7. Are you going to include so-and-so feature in Qt? If so, when?

    We try not to make public speculations about the whats and whens of the next Qt release too early, because we do not want to be known as a vaporware company.

  8. Why did you suddenly release version 1.30? Wasn't the previous release 1.2?

    Some platforms do not support three-level version numbering, therefore the bugfix release following version 1.2 was called 1.21. Version 1.30 is the first major release after 1.2, and the next major release will be 1.40.

  9. I don't want to give away my source code. What do I do?

    Then you need professional license(s).

  10. Can I charge for my application?

    If you have a professional license: Yes, of course. If you use the free license your software must be freely distributable and you must include the source.

    The free license is intended for free software. We realize that CD-ROMs cost money to produce, for example, so you can charge a copying fee.

  11. Where can I find Qt?

    The latest version of Qt can be downloaded from or from, and a whole range of ftp mirror sites around the world. Look for a mirror near you on the list available under

    We encourage all developers of free Qt software to upload their work to

  12. I want to port Qt to a new platform. What do I do?

    If the new platform is POSIX-like and runs the X Window System, it's simple. Read the file PORTING for details. If you succeed you can contact us at

  13. Will Qt be available for [OS/2, Mac, Amiga]?

    At present, Qt only works well on X11 and Win32 (Windows 95 and Windows NT). Porting to other platforms is a lower priority. Currently, we concentrate on the Windows and X versions.

  14. Can I make a Qt shared library and distribute it with my Linux distribution?

    Yes, if you do not make changes to Qt and include all the files present in our distribution of Qt. (That is, you must include the source code.)

  15. Can I distribute dynamically linked applications that use Qt? Can I distribute statically linked applications that use Qt?

    Yes and yes. If you are using the free software license, you may not modify Qt in either case.

  16. I found this obscure bug and I need it fixed, fast!

    We sell support and maintenance contracts. We try to support the developers using the free software license 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.

  17. The Qt demos I've seen only have one window. Can I have several windows in one application?

    Yes, easily.

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