I've been playing around with various ways of creating simple linux applications, and so far have had no easy way of creating a GUI application with a KDE look. I then found Qt Designer, but then realised it was the commercial version and now I've got the opensource edition. Qt Opensource uses widgets and and pretty fundamental C++ classes (although other languages can be used) to create nice looking GUI programs for X window system. The only thing required for you to do is license your program under the GPL (or some other free software license) if you release it. It requires programming experience, but gives the feel of visual c++ with more control. [google]Qt Opensource[/google] and [google]The Independent Qt Tutorial[/google].