An EZwgl program should contain the following components.
EZ.h.
EZ_Initialize or EZ_InitializeXrm.
EZ_CreateWidget or
EZ_CreateWidgetXrm.
EZ_AddWidgetCallBack and EZ_AddEventHandler.
EZ_DisplayWidget on your
toplevel widgets.
EZ_EventMainLoop or
EZ_ServiceEvents or EZ_WaitAndServiceNextEvent.