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diff --git a/doc/faq.doc b/doc/faq.doc new file mode 100644 index 000000000..c187ddbfb --- /dev/null +++ b/doc/faq.doc @@ -0,0 +1,427 @@ +/*! + +\page faq.html + +\title The Qt FAQ + +See also the \link commonproblems.html Technical FAQ\endlink. + +\tableofcontents + +<hr> +\section1 General Questions + +<hr width="30%"> +\section2 What is Qt? + +Qt is a multiplatform C++ GUI toolkit. It +provides application developers with all the functionality +needed to build applications with state-of-the-art graphical +user interfaces. Qt is fully object-oriented, easily +extensible, and allows true component programming. + +Qt is supported on the following platforms: + +\list + \i <b>MS/Windows</b> -- 95, 98, NT 4.0, ME, 2000, and XP + \i <b>Unix/X11</b> -- Linux, Sun Solaris, HP-UX, Compaq Tru64 UNIX, + IBM AIX, SGI IRIX and a wide range of others + \i <b>Macintosh</b> -- Mac OS X + \i <b>Embedded</b> -- Linux platforms with framebuffer support. +\endlist + +It has become the emerging standard development +environment for IT professionals who want to: + +\list + \i Write (and maintain) a single source-tree. + \i Port their applications to multiple platforms with a simple + recompilation. + \i Internationalize their applications. + \i Provide their applications with native look and feel. + \i Have their applications run at native speed. +\endlist + +<hr width="30%"> +\section2 What is Trolltech? + +Trolltech is an international software company with +headquarters in Oslo, the capital of Norway, and with offices +in Brisbane, Australia, and Redwood City, California. Our +flagship product is Qt, the multi-platform C++ GUI toolkit. + +Trolltech ASA was founded in 1994, although, the core team of designers +started Qt's development in 1992. + +More details can be found at \link troll.html Trolltech\endlink. + +<hr width="30%"> +\section2 How can I evaluate Qt? + +We offer 30 day evaluation versions of Qt on all our supported platforms. +Further details can be found here: \l http://www.trolltech.com/evaluate.html. + +<hr width="30%"> +\section2 What does Qt cost? + +This depends on your number of developers, on how many +different platforms you target, and on the edition of Qt you +choose. Currently we offer two different editions (Enterprise +Edition and Professional Edition) on four different +platforms (Microsoft Window, Unix/X11, Macintosh and Linux/embedded). + +We also offer discounts for academic and research institutions. + +Details on pricing can be found here: +\l http://www.trolltech.com/pricing.html. + +<hr width="30%"> +\section2 How can I buy Qt? + +To purchase, please visit the <a +href="https://webshop.trolltech.com/cgi-bin/index.cgi">Trolltech +webshop</a>. In the webshop, you can generate a Purchase Order, order +a Quote, or purchase directly using a credit card. + +For further information and assistance, please contact Trolltech sales: + +Email: \link mailto:sales@trolltech.com sales@trolltech.com\endlink +Phone, US office (for North America): <strong>(+1) 650-813-1676</strong> +Phone, Norway office (for others): <strong>+47 2160 4800</strong> + +<hr width="30%"> +\section2 What kind of technical support is available for Qt? + +Trolltech offers email support to commercial licensees. The first year +of Trolltech's Support and Maintenance Service is included with the +purchase of Qt Professional and Qt Enterprise Edition licenses. +Licenses can be kept up-to-date and fully supported by buying +the Support and Maintenance Service for the licenses held in each +subsequent year. + +For further information see here: +\l http://www.trolltech.com/support/. + +<hr width="30%"> +\section2 Who provides training for Qt? + +A number of companies provide Qt training, in Asia, Europe and the US. +Trolltech has agreements with a number of official training +partners, who offer Trolltech approved courses. In addition +there are a number of independently developed courses run by third +parties. You can find more information about the partners and the +courses here: \l http://www.trolltech.com/training/. + +<hr width="30%"> +\section2 Who provides consultancy for Qt? + +A number of companies provide consultancy services for Qt and +Qtopia. You can find a partial list here: +\l http://www.trolltech.com/company/servicepartners.html. + +<hr width="30%"> +\section2 Are there any books about Qt programming? + +Yes, there are tquite a few books on Qt, most of them +available from amazon.com. You can find a partial list at +\l http://www.trolltech.com/developer/books.html. + +The official Qt book is +<a href="http://www.amazon.com/exec/obidos/ASIN/0131240722/trolltech/">C++ GUI Programming with Qt 3</a>. + +<hr width="30%"> +\section2 What is the Open Source Edition? + +The Qt Open Source Edition is our non-commercial versions of +Qt. You can use this edition to create and run free +software, i.e. software that is licensed under the GNU GPL or +a similarly recognized open source license. + +Qt Open Source edition is available for Unix/X11, Macintosh and +Linux/embedded. + +<hr width="30%"> +\section2 What is the idea behind having a free version of Qt? + +With the Open Source Edition, Trolltech has found a way to support +the free software concept. Part of our commitment is to enable +those who contribute to the free software pool to do so +without paying license fees. + +<hr width="30%"> +\section2 Is there a low-cost version of Qt for writing shareware? + +No, but Qt's commercial licenses permit you to write and sell +shareware written with Qt. + + +<hr> +\section1 Questions about Qt's Users + +<hr width="30%"> +\section2 How many developers use Qt? + +We don't know! We can count our many thousands of commercial +licensees, but the number of free software developers +using Qt can only be guessed based on download figures, book +sales, the number of open source Qt applications available on +the web, Universities teaching with Qt, and other factors. A +conservative estimate would put the figure at around 100,000 to +150,000 developers world-wide. + +<hr width="30%"> +\section2 Which major corporations use Qt? + +See our list of reference customers at +\l http://www.trolltech.com/company/customers.html. Note that many +commercial customers do not disclose their use of Qt because they see +Qt as a competitive advantage. + +<hr width="30%"> +\section2 Are there any well-known applications that use Qt? + +There are many, e.g. Adobe Photoshop Album from Abobe +Corporation and the KDE desktop. A partial list can be found at +\l http://www.trolltech.com/products/qt/apps-using-qt.html + + +<hr> +\section1 Questions about Developing Applications with Qt + +<hr width="30%"> +\section2 Is there a mailing list for Qt? + +Trolltech operates several mailing lists for Qt users including +\c qt-announce, \c qt-interest and \c snapshot-users. + +See \link http://lists.trolltech.com Mailing lists\endlink. + +<hr width="30%"> +\section2 Is Qt's documentation available online? + +Yes, at \l http://doc.trolltech.com. + +<hr width="30%"> +\section2 Is there a technical newsletter for Qt? + +Yes, \link http://doc.trolltech.com/qq/index.html Qt +Quarterly\endlink. It is a paper-based newsletter exclusively +available to Qt licensees. + +As a courtesy and convenience to all our users, a selection of +articles is also published online about one month after publication. + + +<hr width="30%"> +\section2 I think I have found a bug in Qt. Where can I report it? + +Bugs should be reported to \link mailto:qt-bugs@trolltech.com +qt-bugs@trolltech.com\endlink. But \e please read (the very short) +\link bughowto.html How to Report a Bug\endlink page \e first. + + +<hr> +\section1 Questions about Professional Licensing + +<hr width="30%"> +\section2 We have purchased a license, but the developer is leaving the company +project. Can we transfer the license to another developer? + +Yes. Qt licences are for the individual use of named developers. If +the developer associated with a licence leaves the organization, or +moves on to another project that does not retquire a Qt license, +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. + + +<hr width="30%"> +\section2 Can I purchase floating licenses for Qt? + +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 do not +make sense. + + +\omit +#if 0 // ##### Just an idea, no clue if this is policy today +While we want to develop our software for multiple platforms, some +of our developers will only need to work on a single platform. Can +we purchase single packs for those? + +No, you can only purchase single packs as long as you target +one platform only. +#endif +\endomit + +<hr width="30%"> +\section2 Can we use the Open Source Edition while developing our non-free +application and then purchase commercial licenses when we start to +sell it? + +No: our commercial license agreements only apply to software +that was developed with Qt under the agreement. They do not +apply to code that was developed with the Qt Open Source Edition +prior to the agreement. Any software developed with Qt +without a commercial license agreement must be released as +free/open source software. + +<hr> +\section1 Questions about Open Source Software Licensing + +<hr width="30%"> +\section2 I just want to run KDE and other Qt-based software on my +machine. Can I do that with the Open Source Edition? + +Yes. You may use the Qt Open Source Edition for running applications, +both at home and at work, without restrictions. + +<hr width="30%"> +\section2 I want to put Qt, and applications that use it, on a CD-ROM or on +a web site. Can I do that with the Open Source Edition? + +Yes. You may copy and redistribute the Qt Open Source Edition, both +at home and at work, without restrictions. + +<hr width="30%"> +\section2 Can I make software with the Qt Open Source Edition and release it under +the GNU GPL, BSD, or Artistic license? + +Yes. The GNU GPL, GPL-compatible licenses, or any other +approved open source license will do. The FSF.org and +OpenSource.org web sites list approved software licenses. + +<hr width="30%"> +\section2 I don't want to give away my source code. What do I do? + +You need to buy a commercial Qt license. + +<hr width="30%"> +\section2 Is software based on the Qt Open Source Edition really free? Does it +carry any Trolltech-specific license restrictions? + +Yes, it really is free. This is because the Qt Open Source Edition +uses the GNU GPL, which forbids the imposition of any license +restrictions on software based on the Open Source Edition that would +make it non-free. And no, there are no Trolltech-specific +license restrictions on software produced using the Open Source +Edition. + +<hr width="30%"> +\section2 What if Trolltech stops releasing Open Source Editions of Qt? + +We have absolutely no intention of doing that. Together with +the K Desktop Environment project, we have set up the KDE Free +Qt Foundation (see +\l http://www.kde.org/whatiskde/kdefreeqtfoundation.php) to +legally guarantee the availability of Qt for free software +development now and forever - even if circumstances beyound +our control prevent us from producing new free editions. + +<hr width="30%"> +\section2 Using the Open Source Edition, can I make non-free software for internal +use in my company/organization? + +No. Software developed with the Open Source Edition is always free +software, i.e. it can only be distributed under a free +software license. In particular, all the source code for all +the modules your software is based on, regardless of whether +they have been written by you or by others, must be free +software. This is part of our commitment to the free software +community, and enables those who contribute to the free +software pool to do so without paying license fees. + +Although it is possible to write free software for internal +use, it is difficult to ensure that such software is used and +distributed legally. For example, if your free software +retquires any modules that impose conditions on you that +contradict the conditions of the GNU GPL, including, but not +limited to, software patents, commercial license agreements, +copyrighted interface definitions or any sort of +non-disclosure agreement, then you cannot distribute it at +all; hence it cannot be given to consultants, employees for +their personal computers, subsidiaries, other divisions, or +even to new owners. + +Consequently we recommend using commercial licenses for all +internal software development. + + +<hr width="30%"> +\section2 Is Qt Open Source Edition really free software in the GNU meaning of the +word? + +Yes - it is free software both as in "no cost" and as in +"free speech". Even more, it is actually available under the +terms of the GNU GPL. This means you can link GPL'ed software +to it, and you can take code from Qt and put it into other +GPL'ed software. + +<hr width="30%"> +\section2 If the Open Source Edition is GNU GPL, aren't there license conflicts +with incompatible open source licenses? How come people can even +run commercial software like the Opera web browser with it? + +If the Open Source Edition was licensed purely under the GNU GPL, +there would be problems. However, as long as Qt-based +software is either open source or was developed under a +commercial license agreement with Trolltech, we grant +permission to compile, link and run those programs with the +Open Source Edition. This is written down in our second free software +license, the QPL. + +<hr width="30%"> +\section2 Doesn't such an en extra license in addition to the GNU GPL +violate the terms of the GPL or at least make the whole package +GPL-incompatible? + +No, because those extra license terms give you rights in +addition to those of the GNU GPL, including the right to +remove those extra terms. + +<hr width="30%"> +\section2 Why is Qt Open Source Edition not distributed under the GNU Lesser +General Public License (LGPL)? + +The LGPL is designed to "permit developers of non-free +programs to use free libraries" (quote from the LGPL). In +other words, if Qt Open Source Edition were LGPL'd, companies would +not have to purchase our commercial editions in order to make +commercial/proprietary software, they could just use the Open Source +Edition, free of charge. That would mean Trolltech would not +get the revenue necessary for improving and extending Qt. + +Note also that the Free Software Foundation discourages the +use of the LGPL. + + +<hr> +\section1 Questions about other programming languages + +<hr width="30%"> +\section2 Are there bindings to languages other than C++? + +Yes there are, e.g. bindings to Perl (PerlQt) and Python +(PyQt). These bindings were written by the open source +community and are not supported by Trolltech. + +<hr width="30%"> +\section2 Can I develop commercial applications with PerlQt or PyQt or other +Qt wrappers? + +Yes, if you have purchased a commercial 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. All developers that write code +containing calls to the Qt API (directly or through a wrapper) +need Qt licenses. + +*/ |