Mondrian is an OLAP (online analytical processing) engine written in Java. It reads from JDBC data sources, aggregates data in a memory cache, and implements the MDX language and the olap4j and XML/A APIs.
OLAP mapper is an OLAP engine written in Java. It enables you to interactively analyze very large datasets stored in SQL databases without writing SQL. The main concept of application is based on the star schema visualization.
JBAM is open source Business Activity Monitoring system based on J2EE technology. Able to work with any commercial/non-commercial workflow engine, because of its generic architecture