Addns.pl is a self-contained DynDNS update client for DynDNS.org (and possibly others). It supports a variety of IP detection methods including external webcheck/router pages. It also supports multiple configurations and hostnames, smart abuse prevention, and custom/static/dynamic DNS, and can run as a daemon, commandline options only, or with a configuration file.
tzoperlcc3 is a TZO.com Dynamic DNS client which seemlessly integrates into the administration interface in the Cobat Qube 3 Internet Appliance server. This allows for Qube 3 users to use any of TZO.com's DNS/domain services on a dynamic or static IP address. The client also has an auto-update feature which can be configured to check for IP changes from once every minute to once a day, and allows e-mailing to the user if the address does change.
Dents is a from-scratch implementation of the server side of the DNS protocol, sharing no code with any other project. Among its several features are compatibility with named, a modular driver system and an extensible control facility which allows the administrator to control the running server.
DNRD is a proxy DNS daemon. It supports several forward servers for redundancy and/or load-balancing. DNS queries for specific domains can be forwarded to a specific group of DNS servers (with redundancy and load balancing) for that domain. It is very useful in VPN and dialup environments but can also be used as a DNS cache or ad-blocker for networks and workstations.