From bd0f3345a938b35ce6a12f6150373b0955b8dd12 Mon Sep 17 00:00:00 2001 From: Timothy Pearson Date: Sun, 10 Jul 2011 15:24:15 -0500 Subject: Add Qt3 development HEAD version --- doc/html/faq.html | 502 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 502 insertions(+) create mode 100644 doc/html/faq.html (limited to 'doc/html/faq.html') diff --git a/doc/html/faq.html b/doc/html/faq.html new file mode 100644 index 0000000..ff21fba --- /dev/null +++ b/doc/html/faq.html @@ -0,0 +1,502 @@ + + + + + +The Qt FAQ + + + + + + + +

The Qt FAQ

+ + +

General Questions +

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: +

MS/Windows -- 95, 98, NT 4.0, ME, 2000, and XP +
Unix/X11 -- Linux, Sun Solaris, HP-UX, Compaq Tru64 UNIX, +IBM AIX, SGI IRIX and a wide range of others +
Macintosh -- Mac OS X +
Embedded -- Linux platforms with framebuffer support. +

It has become the emerging standard development +environment for IT professionals who want to: +

Write (and maintain) a single source-tree. +
Port their applications to multiple platforms with a simple +recompilation. +
Internationalize their applications. +
Provide their applications with native look and feel. +
Have their applications run at native speed. +

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 Trolltech. +

How can I evaluate Qt? +

We offer 30 day evaluation versions of Qt on all our supported platforms. +Further details can be found here: http://www.trolltech.com/evaluate.html. +

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: +http://www.trolltech.com/pricing.html. +

How can I buy Qt? +

To purchase, please visit the Trolltech +webshop. 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: sales@trolltech.com +Phone, US office (for North America): (+1) 650-813-1676 +Phone, Norway office (for others): +47 2160 4800 +

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: +http://www.trolltech.com/support/. +

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: http://www.trolltech.com/training/. +

Who provides consultancy for Qt? +

A number of companies provide consultancy services for Qt and +Qtopia. You can find a partial list here: +http://www.trolltech.com/company/servicepartners.html. +

Are there any books about Qt programming? +

Yes, there are quite a few books on Qt, most of them +available from amazon.com. You can find a partial list at +http://www.trolltech.com/developer/books.html. +

The official Qt book is +C++ GUI Programming with Qt 3. +

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. +

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. +

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. +

Questions about Qt's Users +

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. +

Which major corporations use Qt? +

See our list of reference customers at +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. +

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 +http://www.trolltech.com/products/qt/apps-using-qt.html +

Questions about Developing Applications with Qt +

Is there a mailing list for Qt? +

Trolltech operates several mailing lists for Qt users including +qt-announce, qt-interest and snapshot-users. +

See Mailing lists. +

Is Qt's documentation available online? +

Yes, at http://doc.trolltech.com. +

Is there a technical newsletter for Qt? +

Yes, Qt +Quarterly. 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. +

I think I have found a bug in Qt. Where can I report it? +

Bugs should be reported to qt-bugs@trolltech.com. But please read (the very short) +How to Report a Bug page first. +

Questions about Professional Licensing +

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 require 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. +

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. +

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. +

Questions about Open Source Software Licensing +

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. +

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. +

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. +

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

You need to buy a commercial Qt license. +

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. +

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 +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. +

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 +requires 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. +

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. +

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. +

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. +

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. +

Questions about other programming languages +

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. +

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. +

+ +

Trademarks +

Qt 3.3.8

+ -- cgit v1.2.3