Apple's developer documentation provides lots of information about Bonjour
in its <a href="http://developer.apple.com/documentation/Cocoa/Conceptual/NetServices/Articles/about.html#//apple_ref/doc/uid/TP40002458-SW1">Bonjour overview</a>.
If you are writing an application that wants to discover services on the network,
use DNSSD::ServiceBrowser. You can also find available service types using ServiceTypeBrowser.
If you want to announce the availability of a service provided by your application,
use DNSSD::PublicService.
DNSSD::DomainBrowser allows you to find domains (other than the local one) recommended
for browsing or publishing to.
Note that DNSSD::ServiceBrowser::isAvailable() provides information about the availability
of the services provided by this library generally, not just for browsing services.