[fpc-pascal] libQT4Pas - Why it is needed?

[Krzysztof]

Hi,

I am wondering. If I build application for linux using gtk2 widgetset
for GNOME (or XFCE etc.) and send this program to my friend, then he
can run it without any external librarys (of course if he have gnome
too), this same thing on windows. But why when I build application on
KDE interface I need some external libQT4Pas to run it and my friend
need it too (he have KDE so all QT librarys too)? There is no
libGTK4Pas so why exists layer libQT4Pas? What is difference between
GTK and QT librarys?

Regards