WDM (WINGs Display Manager) is a modification of XFree86's xdm package for graphically handling authentication and system login. Most of xdm has been preserved with the Login interface based on a WINGs. WDM combines the functions of a graphical display manager identifying and authenticating a user on a system with some of the functions of a session manager in selecting and starting a window manager. Optionally, wdm can shutdown (reboot or halt) the system.