Avahi in Launchpad

Avahi

Registered 2005-09-29 by Avahi

Avahi is a fully LGPL framework for Multicast DNS Service Discovery.
It allows programs to publish and discover services and hosts running on a local network with no specific configuration.
For example you can plug into a network and instantly find printers to print to, files to look at and people to talk to.

Avahi is designed to be compatible with the mDNS/DNS-SD specification and boasts the following features

Fully open source and freely available under the LGPL
Full IPv4 and IPv6 support
An embeddable mDNS stack
Dynamic adjustment to network reconfiguration
Daemon with DBUS API for desktop applications
C library to interface with the DBUS API
C# library
Compatible with other mDNS/DNS-SD implementations such as Howl and Apple Bonjour (previously Rendezvous)
Ability to correctly "reflect" mDNS between two or more LAN segments
Ability to configure DNS servers based on mDNS/DNS-SD published information, a feature that is very usefull on IPv6 which has no other mechanism for this.
Combined with nss-mdns, allows hostname lookup such as 'laptop.local' without the configuration of a DNS server.
Easy integration into GLIB, QT3, QT4 mainloop applications.
Documentation and examples of both developer APIs and utilities.

mDNS/DNS-SD is part of a larger set of specifications for easy configuration of networking known as "ZeroConf" (http://www.zeroconf.org/), with the aim of allowing you to plug into a network and instantly be able to interact with it's services.

Avahi was designed to be a fully free implementation, and is available under the LGPL. Many other implementations of the mDNS/DNS-SD specification were previously non-free, restricting their use in many platforms such as the GNOME desktop and many distributions.