MyGeneration is great at generating ORM architectures or O/R Mapping files for architectures such as Gentle.NET, Opf3, NHibernate, and others. The meta-data from your database is made available to the templates through the MyMeta API. MyGeneration supports Microsoft SQL, Oracle, IBM DB2, MySQL, PostgreSQL, Microsoft Access, FireBird, Interbase, SQLite and VistaDB. For a quick presentation see MyGeneration Help - Overview. There's also the Data Mapping Architecture: Entity Spaces.