dnscrypt-proxy acts as a DNS proxy between a regular client, like a DNS cache or an operating system stub resolver, and a DNSCrypt-aware resolver, like OpenDNS. The DNSCrypt protocol focuses on securing communications between a client and its first-level resolver. While not providing end-to-end security, it protects the local network (which is often the weakest link in the chain) against man-in-the-middle attacks. It also provides some confidentiality to DNS queries.
adsuck is a small DNS server that spoofs blacklisted addresses and forwards all other queries. The idea is to be able to prevent connections to undesirable sites such as ad servers, crawlers, etc. It can be used locally, for the road warrior, or on the network perimeter in order to protect local machines from malicious sites.
DNSCrypt OSX Client is a user interface to conveniently start/stop dnscrypt-proxy and change DNS settings. It was specifically designed to use DNSCrypt with the OpenDNS public DNS resolvers. It includes a preference pane, a menu bar indicator, and a set of scripts for interacting with the system.
radns is a small, portable client-side implementation of the RDNSS option in IPv6 Router Advertisements (RFC 5006) that is used to get the address of a resolving DNS server. It listens for Router Advertisements with the Recursive DNS Server (RDNSS) option and stores the addresses in a file following the same syntax as resolv.conf. It optionally calls a script to handle, for instance, DHCP clients that compete for ownership of /etc/resolv.conf or to set the DNS server on systems that don't use resolv.conf at all. It can be easily integrated with the resolvconf(8) program.
slapi-dnsnotify is a plugin for OpenLDAP or other LDAP servers. It watches for changes in the serial number of a DNS zone stored in the LDAP server, and notifies DNS slave servers to refresh their copy of the zone. It can also increment the serial number of a zone whenever changes in that zone are made.
xbaydns provides a Web management interface for BIND 9. Its user-friendly Web interface is based on the Django framework. It has been tested on many OSes, including FreeBSD, Linux, and MacOS X Leopard. It provides an easy-to-use Web interface for DNS record management while implementing most of the advanced features provided by BIND.
dnstop is a libpcap application (ala tcpdump) that displays various tables of DNS traffic on your network. It currently displays tables of source IP addresses, destination IP addresses, query types, response codes, opcodes, top level domains, second level domains, third level domains, etc.