1. A vehicular information system developing apparatus comprising: an input section through which graphics-related data are externally input, said graphics-related data including graphics data relating to figures to be displayed on a screen and operation description data that are set for respective figures and describe operations of the figures on the screen; a storage section for storing control data to be used for controlling transition between display states in accordance with a prescribed command and display control data to be used for displaying figures on the screen in each state based on the operation description data; and a conversion section for incorporating the graphics-related data into the display control data and for generating an execution program resulting data and the control data.