lsof

ftp://lsof.itap.purdue.edu/pub/tools/unix/lsof/FAQ#1.9

Copyright 2002 Purdue Research Foundation, West Lafayette,
Indiana 47907.  All rights reserved.

Written by Victor A. Abell

This software is not subject to any license of the American
Telephone and Telegraph Company or the Regents of the
University of California.

Permission is granted to anyone to use this software for
any purpose on any computer system, and to alter it and
redistribute it freely, subject to the following
restrictions:

1. Neither the authors nor Purdue University are responsible
   for any consequences of the use of this software.

2. The origin of this software must not be misrepresented,
   either by explicit claim or by omission.  Credit to the
   authors and Purdue University must appear in documentation
   and sources.

3. Altered versions must be plainly marked as such, and must
   not be misrepresented as being the original software.

4. This notice may not be removed or altered.