DNS Service Discovery API Reference for C
The DNSServiceDiscovery API is part of Bonjour, Apple's implementation of zero-configuration networking (ZEROCONF).
Bonjour allows you to register a network service, such as a printer or file server, so that it can be found by name or browsed for by service type and domain. Using Bonjour, applications can discover what services are available on the network, along with all necessary access information (such as name, IP address, and port number) for a given service.