JavaGroups is a Java package for reliable group communication. It consists of 3 parts: The first part is a socket-like API for application development, providing methods for joining and leaving a group, sending multicast messages to members, and receiving notifications when members join/leave/crash. The second part is a protocol stack which implements reliable communication, and can be configured according to the QoS desired. New protocols can easily be added, and existing ones removed/replaced/modified. The third part is a set of building blocks which give the application/protocol programmer high-level abstractions (e.g. DistributedHashtable, derived from java.util.Hashtable, which is similar to Linda/JavaSpaces).
