> Oberon has a text user interface (TUI), which has to be differentiated from the terminal user interface. It combines the point-and-click convenience of a graphical user interface (GUI) with the linguistic strength of a command line interface (CLI) and is closely tied to the naming conventions of the Oberon language. Any text appearing (almost) anywhere on the screen can be edited and can therefore be used as command input. Commands are activated by a middle-mouse click on a text fragment of the form Module.Command (optionally followed by Parameters, which are terminated by ~). A command is defined by a procedure, which has an empty argument list. Parameters to the command have to be defined before executing the middle click and must be explicitly scanned and retrieved by the procedure. There are no checks nor any questions asked during command execution. This is sometimes called a "non-modal" user interface (UI). Nothing like a command prompt is required.