Walter/Jay,

From an architectual view, I'd say that keeping you business rules layer in a data centric programming language (like VFP) makes more sense than trying to do this in a low level language like Java or .NET. It might pay off when business rules are less static. You can store the business rules in a table, and process them in VFP very clean and quickly. This is much harder to do in .NET or java technologies.

If business rules are going to reside in database tables, you can use SQL Server/Oracle stored procedures to read/process the tables. Many use this approach and find it efficient. You can also use ADO.NET for any subsequent processing of results sets from the back-end.

Kevin