I think very one is in favor of one connection interface but like cross platform it's just a dream. The best anyone can do (at the moment) is create a tool that can configure a backend class. A dataManager that somehow can change the methods to connect, Insert, Update, etc. Database engines are to different. Take a simple case:

MySQL = SHOW TABLES
Postgres = SELECT relname FROM pg_class WHERE NOT relname LIKE '%pg%'

These two are just the tip of the problem. From the VFP side there are two standard ways to connect ODBC or OLE DB. But someone could create a COM object to handle connections etc.

It's just a dream.
John