I have a proyect in Delphi XE3 using VCL application, now I want to improve my application GUI and I want to use a Qt GUI Widget with stylesheets using my existing delphi source code (implemented classes,...) , it's this possible?. I has been search on Net but nothing founded about implementing Qt GUI for Delphi. Thx in advanced.
There are no Delphi bindings for Qt: http://en.wikipedia.org/wiki/List_of_language_bindings_for_Qt_4
Delphi is inextricably bound to either the VCL or Firemonkey. Without no bindings available, you can't directly use Qt in Delphi.
A possible workaround could be to abstract your application routines into a DLL and then create the GUI for your application in another language with Qt support and call your Delphi routines from that.
Also @ Mason:
Delphi tried going the Qt route several years ago, and it was a miserable failure
The failure of Kylix had nothing to do with Qt.