On Jul 21, 2005, at 1:05 AM, Robert Purves wrote: > All UNIX processes have a PID, but only a subset have a > ProcessSerialNumber and are visible to GetNextProcess. Thanks Robert. That explains the behavior observed. Is there some newer manager (since the process manager is old) Activity Monitor uses to retrieve all PIDs that don't have PSNs? I remember seeing an "extended" processInfoRec. Brian S.