The FrigoSim user interface presents a look and feel like most Microsoft Windows programs.
It is first of all based on a number of menu commands.
The most frequently used commands are also activated by tool buttons placed
in a tool bar just below the menu bar. Alternatively
a set of mouse operations can be used for speed-up.
The right mouse-button activates a pop-up menu with commands relevant for the focused Window.
Commands not relevant for the selected item (if any) will be disabled (greyed).
The interface can be dressed up in a number of languages, see Languages.
The FrigoSim window by default fills the entire screen.
For quick transfer of data to and from other programs the normalize button (mid-button at upper right)
can be pressed. This produces a smaller FrigoSim window for resolutions above VGA (640 x 480).
A fourth window can be evoked for studying the impact of instant changes,
see Instant change mechanism.