This software is Copyright (C) 2007 by Brian Marick <marick@exampler.com>. It is licensed according to “the Ruby license”. Specifically:

You can redistribute it and/or modify it under either the terms of the GNU General Public License, version 2, <www.gnu.org/licenses/old-licenses/gpl-2.0.html> or the conditions below:

1. You may make and give away verbatim copies of the source form of the
   software without restriction, provided that you duplicate all of the
   original copyright notices and associated disclaimers.

2. You may modify your copy of the software in any way, provided that
   you do at least ONE of the following:

     a) place your modifications in the Public Domain or otherwise
        make them Freely Available, such as by posting said
        modifications to Usenet or an equivalent medium, or by allowing
        the author to include your modifications in the software.

     b) use the modified software only within your corporation or
        organization.

     c) make other distribution arrangements with the author.

3. You may modify and include part of the software into any other
   software (possibly commercial).  

4. Text or files supplied as input to or produced as output from 
   the software do not automatically fall under the copyright of the
   software, but belong to whomever generated them, and may be sold
   commercially, and may be aggregated with this software.

5. THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
   IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   PURPOSE.