The following copyright message is included in  the file "top.c" of top
version "top-3.5beta5":

/*
 *  Top users/processes display for Unix
 *  Version 3
 *
 *  This program may be freely redistributed,
 *  but this entire comment MUST remain intact.
 *
 *  Copyright (c) 1984, 1989, William LeFebvre, Rice University
 *  Copyright (c) 1989 - 1994, William LeFebvre, Northwestern University
 *  Copyright (c) 1994, 1995, William LeFebvre, Argonne National Laboratory
 *  Copyright (c) 1996, William LeFebvre, Group sys Consulting
 */