Tryst is a 'proof of concept' implementation of Apple's Bonjour (formerly known as Rendezvous) for GNUstep.

It 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 Tryst, 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.