JXTA is NOT a file-sharing application. It is a language, platform, and transport-independent protocol for Internet communication. Although JXTA can be used for any type of networking, it primarily focuses on solving the problems encountered in peer-to-peer networking, such as routing, discovery, and searching. Communication using the JXTA protocol is carried out by sending messages in a sort of pseudo-XML over any type of networking protocol you can think of. The reference implementation of JXTA allows HTTP and TCP to be used for communication, but there is no reason why cows with message text spray painted on their stomachs couldn't be used.