The Free GPL edition of QT has some restrictions on it, but I am somewhat confused as to what they mean. Trolltech say that software developed with the free version of QT must be 'Free/Open Source' software, but they do not specify their definition of 'free' in this sense (i.e. free as in free speech or as in no cost).

Secondly, I get the impression that software developed with the free QT edition cannot work under Windows, yet a main advantage of using QT in the first place is that it's cross-platform.

Finally, I am a bit confused about the first book in the list on this page: http://www.trolltech.com/developer/books.html called C++ GUI Programming with QT 3. Does it teach you how to program in C++ and QT?

Can anyone clarify any of these issues? Thanks.

I've found that the answer to the first question is that it demands your software is free as in free speech, but not necessarily at no cost.

And I've found that the answer to the last question about the book is that it only teaches you QT and not C++.

Does anybody know about the second question?

C++ GUI Programming in Qt3, is the latest book on Qt available nowadays, I've used it and it is very easy to follow, and I think it is one of the best books on Qt, I've used KDE programming bible before it has a chapter on Qt, but it is outdated.

But you would need to know C++ beforehand, inorder to use the book efficiently.

the only restriction I know in Qt GPL edition, is that every software created in it has to adhere to the GPL hence be 'free as in free speech, not as in free beer"

I think you need to install QT for Windows in order to run Qt programs

I see. Thank you.

Qt can run on any platform, but some tweaking and necessary libraries must be done. Qt is open-source free (and should already be installed if using KDE) for linux and mac. The windows version requires you to buy a license to use it. A trial version for windows is available at www.trolltech.com (the main site). Their C++ GUI book is very nice.