Mondrian OLAP server

Mondrian is an Open Source OLAP (online analytical processing) server, written in the Java programming language. It supports the MDX (multidimensional expressions) query language and the XML for Analysis and JOLAP (JSR-000069) specifications. It reads from SQL and other data sources and aggregates data in a memory cache.

It became part of the Pentaho business intelligence suite in November 2005.