TZO Internet Naming System - Version 1.5 TZO uses true Dynamic DNS client/server technology to fix a static domain name to a Dynamic IP address, allowing Internet users with dial-up modems or cable/xDSL/ISDN modems to host their own Web, FTP, Mail or Game Server or other TCP/IP services from their home PC. TZO makes it easier for others when connecting to your PC, since they can use a true Internet domain name to connect, and not an ever changing IP address.