ProxyDNSFilters are two tools that can be useful for web filtering: a custom filtered DNS relay server and a custom filtered Proxy server. (filtering by custom IPs, MACs and sites). Basic SOCKS v4 & v5 is also supported. Useful for schools or libraries.
A simple desktop DNS client that provide the complete set of infos received from the DNS server. It can be used programmatically. Framework .NET 2.0 required.
DotDNS is a Dynamic DNS client and server software that can work with your own domains. It will work on standard W2K/W2003 servers. *UPDATE* MSSQL Express is designated as backend for storage.