Is the Eclipse RCP "Window > Show View" menu predefined somewhere

Question

I am trying to understand Eclipse RCP to maintain an Eclipse application. I created a template example with the "RCP 3.x application with a view" wizard. It opens a bare window with a single view, no toolbar, no nothing. A tutorial showed me how to add a basic "File" > "Exit" action like so:

plugin.xml

<extension
      point="org.eclipse.ui.menus">
   <menuContribution
         locationURI="menu:org.eclipse.ui.main.menu">
      <menu
            label="File">
         <command
               commandId="org.eclipse.ui.file.exit"
               label="Exit">
         </command>
      </menu>
   </menuContribution>      
</extension>

The mechanism is clear enough. Now I want to add the "Window" > "Show View" action that all other Eclipse products I know of (Java, PDE, J2EE) have. The application that I'm trying to get into also has it, and it doesn't seem to define it anywhere in any of its' components' plugin.xmls. So, is there some native Eclipse plugin that defines the "Window" menu and this action? Where would I find it? I'm pretty baffled by how hard it has been to find any information on this. I've found a few things from which I could piece together how to manually create this action, but that isn't what I want.