Tool for examining the internals of Qt application

 GammaRay is a tool for examining the internals of a Qt application and
 to some extent also manipulate it. GammaRay uses injection methods to
 hook into an application at runtime and provide access to a wide variety
 of interesting information. It provides easy ways of navigating through
 the complex internal structures you find in some Qt frameworks, such as
 QGraphicsView, model/view, QTextDocument, state machines and more.