Applications on this CD-ROM require a PC with Windows 95, 98, 2000, Me, or XP using the Cygwin UNIX environment ( freely downloadable at www.cygwin.com ) or Linux (Red Hat 6.1 or later, or comparable Linux distribution); 486 or higher CPU; 64MB RAM; 60MB disk space; CD-ROM drive; Internet access and Web browser (for the WebAgent example).