The Zeroconf working group is working towards zero configuration IP networking. Multi-cast DNS and DNS service discovery provide a convient ways for devices and services to register themselves, and to discover other network-based services without relying on centrally administered services.
Java as a language is not appropriate for low-level network configuration, but it is very useful for service registration and discovery. JmDNS provides easy-to-use pure-Java mDNS implementation that runs on most JDK1.4 compatible VMs.
The code is released under the LGPL license so that it can be freely incorporated into other products and services.
Many thanks to Stuart Cheshire for help and moral support.