Jini Connection Technology - Primary Sun Microsystems site. "Jini enables spontaneous networking of a wide variety of hardware, software, and services."
Jini Corner at Artima.com - Jini-users FAQ, links to Jini resources on the web, discussion forum, a Jini interface repository, the service UI specification, and articles about Jini from the Jiniology column.
Jini Planet - Information, by Jini developer, author of "Core Jini", Keith Edwards.
Openwings - Sun and Motorola sponsored open specifications for a framework that enables the development of highly available, secure, distributed systems for mission critical applications. The first implementation is built on Jini.
Sun: Jini-Users - Jini related maillist. Subscribe or search archives.
Sun.com: Rio Architecture Overview - Rio is a layer on top of Jini that addresses quality of service, deployment and failover of Jini services. [PDF]