Microsoft's Metadata Management
The metadata services is part of MS SQL Server 2000.
Their model management techonology uses an algorithm called CUPID to map two data sources together. It was developed by Phil Bernstein. The paper goes through the various different way to match two different models (or database/xml schemas) using linguistic, element, structure, referential and contextual matching.
Another such tool is ARTEMIS here's a paper called: "A Schema Analysis and Reconciliation Tool Environment for Heterogeneous Databases":
The MOMIS Project is the parent project: