With its various distributed data structures, distributed caching capabilities, elastic nature, memcache support, integration with Spring and Hibernate and more importantly with so many happy users, Hazelcast is feature-rich, enterprise-ready and developer-friendly in-memory data grid solution.
- Distributed implementations of 
java.util.{Queue, Set, List, Map} - Distributed implementation of 
java.util.concurrency.locks.Lock - Distributed implementation of 
java.util.concurrent.ExecutorService - Distributed 
MultiMapfor one-to-many relationships - Distributed 
Topicfor publish/subscribe messaging - Synchronous (write-through) and asynchronous (write-behind) persistence
 - Transaction support
 - Socket level encryption support for secure clusters
 - Second level cache provider for Hibernate
 - Monitoring and management of the cluster via JMX
 - Dynamic HTTP session clustering
 - Support for cluster info and membership events
 - Dynamic discovery, scaling, partitioning with backups and fail-over
 
See documentation at www.hazelcast.com
Download from www.hazelcast.com
Or use Maven snippet:
<dependency>
    <groupId>com.hazelcast</groupId>
    <artifactId>hazelcast</artifactId>
    <version>${hazelcast.version}</version>
</dependency>Maven snippet:
<dependency>
    <groupId>com.hazelcast</groupId>
    <artifactId>hazelcast</artifactId>
    <version>${hazelcast.version}</version>
</dependency>
<repository>
    <id>sonatype-snapshots</id>
    <name>Sonatype Snapshot Repository</name>
    <url>https://oss.sonatype.org/content/repositories/snapshots</url>
    <releases>
        <enabled>false</enabled>
    </releases>
    <snapshots>
        <enabled>true</enabled>
    </snapshots>
</repository>Pull latest from repo git pull origin 3.0 and use Maven install (or package) to build mvn clean install.
Hazelcast has 3 testing profiles (default profile doesn't run any tests):
- Type 
mvn test -P parallel-testto run tests those can be run in-parallel without using network. - Type 
mvn test -P serial-testto run tests those cannot be run in-parallel. - Type 
mvn test -P all-teststo run all test serially using network. 
Please join the mail group if you are interested in using or developing Hazelcast.
http://groups.google.com/group/hazelcast
Hazelcast is available under the Apache 2 License.
Copyright (c) 2008-2013, Hazelcast, Inc. All Rights Reserved.
Visit www.hazelcast.com for more info.