Modelator

Modelator is a professional database design tool, made by MetodeData. It is based on the well-known Entity-Relationship modeling principle, and has a "easy to use" - but powerful - graphical interface.

You may export the data model to any database format, or reverse an existing database into Modelator to graphically display the data model (for analysis or documentation purposes). You may even use Modelator to convert a database from one format to another!