One of my earliest open source attempts and probably the one of the lowest quality. It’s included here for completeness, if not nostalgia. Tieout was originally conceived because there was a set of OLAP cubes that had the same data as a relational database, even at upper-level members. So the theory was, what if we could parameterize queries with the same variables and issue them to the source database (via JDBC) and to Essbase (via Essbase/MDX) and compare the results? Tieout was born. It’s a bit esoteric but there might be something for someone in here.
Licensed under GPLv3 and available on Google Code in the Tieout repository.