OpenCluster is a distributed hashmap service that is designed for both high performance and scalability.
OpenCluster stores data in maps. The map itself is a container of key/value pairs.
OpenCluster is open-source software, which means that the code is available to be modified to your perticular needs (within the limits of GPL licencing, which essentially means you are free to modify it with no restrictions for your own use, but if you wish to distribute your modified version, you must also include the source code of this modified version)
OpenCluster is still in active development. It is currenly available as source code on github.
OpenCluster is still in the early stages of active development, but we hope to have a stable version of the server available by the end of 2012.
Work is being done on Java and C client libraries, with other languages planned for the future.