The topbar menu is, as the name suggests, located at the top of a screen and provides access to important submenues. It is visible most of the time except when a relatively small screen is in use where it may be obscured by certain windows. The keyboard shortcut Alt-U may be used to activate this menu. After activating an item, the menu stays opened and pushes itself behind other windows.
On the keyboard, the Left and Right cursor keys can be used to select a particular menu item, which may then be activated by the Down cursor key or the Return key. With the mouse, a single click on the desired menu item is sufficient to activate it.
The topbar menu provides access to the following submenues: