Embodiments of {HEAD ~ a distributed instant messaging system} that uses {TAIL ~ a distributed index} in peer to peer networks 
uses
Embodiments of { HEAD ~ a distributed instant messaging system } that uses { TAIL ~ a distributed index } in peer to peer networks
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH