THelloWorldView, defined in HelloWorldView.h and HelloWorldView.C, defines a subclass of TDocumentComponentView that displays the text, using TTextDisplay, in the model.
THelloWorldPresenter, defined in HelloWorldPresenter.h and HelloWorldPresenter.C, defines a subclass of TGUIPresenter that overrides HandleCreateMainView to get the root view out of the archive associated with its library, and return the view. Note that it sets the view's GUIBundle before returning it.
HelloWorldPresenter.C also defines a global static stationery instance,using the TGUIModelPresenterStationeryFor<> template. This object is used by RunDocument (in the script UIBHelloWorldApp) to launch the document.