SwarmCache
SwarmCache is a simple but effective distributed cache. It uses IP multicast to efficiently communicate with any number of hosts on a LAN. It is specifically designed for use by clustered, database-driven web applications. Such applications typically have many more read operations than write operations, which allows SwarmCache to deliver the greatest performance gains. SwarmCache uses JavaGroups internally to manage the membership and communications of its distributed cache.
(追記) (追記ここまで)
License
GNU Library or Lesser General Public License (LGPL)