Window menu

Show/Hide Tool Palette
This only applies if you have chosen in the Tool Palette preferences to put the tool palette in its own window.
New Window on —
You can look at the same document in several different windows; Zoom and scroll each window however you like.
Close Window
Close the frontmost window you have open. If you have unsaved changes, you are prompted to save or discard them.
Minimize Window
Shrink the frontmost window into the Dock.
Zoom Window
Size the window to fit its contents, or return to the previous window size.
Bring All to Front
Put all of OmniGraffle's windows in front of other applications' windows.