Copyright 1996 The Board of Trustees of The Leland Stanford Junior University. All rights reserved. Except for commercial resale, lease, license or other commercial transactions, permission is hereby given to use, copy, and/or modify this software, provided that the above copyright notice and this permission notice appear in all copies of this software. No part of this software or any derivatives thereof may be used in the production of computer models for resale or for use in a commercial product. This software is provided "as is" and without warranty of any kind, express, implied or otherwise, including without limitation, any warranty of merchantability or fitness for a particular purpose.