A JXTA appliance is similar to routers, firewalls, and other network hardware. The idea of a JXTA appliance is to put into dedicated hardware the parts of the JXTA platform that are generic and key parts of the virtual P2P network.
JXTA has the equivalent components of a router, an HTTP store-and-forward gateway, and service discovery. Each peer may supply these services to other peers. Besides running applications, each peer may be an active part of the virtual network. By using appliances, the burden of supplying the virtual network is offloaded from many of the peers. Obviously, the appliance can also be tuned to perform such functions at higher speeds and capacities.
The idea of an appliance is familiar. The appliance can have management functions and additional software tailored to corporate and Internet service provider norms of control and monitoring so that it's much like a traditional router, firewall, or proxy server. The more network managers and their bosses feel that they have control of what's going on, the more JXTA and P2P applications will flourish.
Why is there money in appliances? JXTA applications are being written and used all over the world, and network managers are getting itchy to control that traffic. The appliances can also improve the utilization of bandwidth by ensuring that some functions are on the local network and not accessed via the external Internet. Of course, there is also the ability of the network manager to block specific traffic. Call it security, censorship, or paranoia, blocking still sells big.