The set of routines in the drawing package allows the visualisation of the volumes of the detector. These routines can be called from the user program or interactively via the command interface. The output can be directed onto the screen or to a file. The graphics of GEANT is based on the HIGZ [] package. HIGZ is a high-level interface between the user program (in this case GEANT), ZEBRA and a basic graphics library. At the moment of writing, HIGZ can use various flavours of the GKS [,,]
graphics system or the X11[] system. A version based on the PHIGS[] system is now being developed at CERN.