V_Sim visualizes atomic structures such as crystals, grain boundaries and so on (either in .d3 format as defined by F. Lançon, or in plain text format as described in the sample page). The rendering is done in pseudo-3D with colored sphere to represent the atoms. The user can interact through many functions to choose the view, the size of the atoms, their color, the background color, the type of fog... Much of it is detailled in the user guide. Moreover V_Sim allows to export the view as image in GIF, PS or more formats. WWW: http://inac.cea.fr/L_Sim/V_Sim/