Mondrian 1.0 is the culmination of over two years of development, and marks the first production-quality Open Source OLAP Server.
This release adds support for aggregations based upon distinct-counts, and enables JDBC connection-pooling; it also provides comprehensive support for XML for Analysis, and includes lots of bug-fixes.
See release notes at http://sourceforge.net/project/shownotes.php?release_id=178687.