gconf-sharp Gtk# is thread aware, but not thread safe; See the Gtk# Thread Programming for details. System.Delegate To be added. To be added. NotifyEventHandler is a delegate object that can be used to notify your program whenever a key's value is changed, either in your program or externally (i.e. via gconf-editor). You only have to attach a GConf.NotifyEventHandler delegate to a key, this way: gconfClient.AddNotify (key, new GConf.NotifyEventHandler(function)); This is very important for graphic interfaces, as it is a good practice to make the application react instantly to preference changes. System.Void