Previously the pages, layout spaces, etc. were only opened via the popup menu item Open in new window in a docked editor. Now you have the possibility to also define undocked editors as main working windows. The popup menu item Main working window is available to this purpose in the title bar of the respective editor. An editor activated as a main window is highlighted by a blue frame.
By default a page, a layout space, etc. is opened in an active, docked editor in the main widow or in an active, undocked editor. If an editor is defined as the main working window, pages, layout spaces, etc. are always opened in this undocked editor via the popup menu item Open in new window. If no page, layout space, etc. is opened, the undocked editor defined as a main window is first filled with contents when opening (e.g. via a double click).
See also