KDevelop/ QT Designer are for KDE/QT development
I am having problems with designing in GTK.
If I click on text box object it fill up the entire window.
You need to add some kinda container such as a GtkTable , or GTKFixed, if your used to a VisualBasic style design, its prolly best to use GTKFixed since you can just plop your butttons/listboxes/whatever anywhere
In glade you can use libglade with your c/c++/ada95 projects Using libglade