1. http://rubis.ow2.org/index.html as of Oct 2010. http://rubis.ow2.org/index.html as of Oct 2010.
2. Apache cassandra database. http://cassandra.apache.org/. Apache cassandra database. http://cassandra.apache.org/.
3. Hbase: Hadoop database. http://hbase.apache.org. Hbase: Hadoop database. http://hbase.apache.org.
4. MongoDB. http://www.mongodb.com. MongoDB. http://www.mongodb.com.
5. Asynchronous view maintenance for VLSD databases