iCalamus can use multiple views of a document at once. All views are updated immediately, and you can basically edit a document in all views at the same time.
Use this menu item if you want to add more views to the active document in separate document windows. Choose if you want to add a master page view or a layout page view. Other document types than the default one can offer other page view options.
The difference between master pages and layout pages is described
in the section Document view
of the manual chapter
Document windows
.
