>Hi, Please advise regarding the following design:
>
>1) Front end is based in .NET (WinForms and WebForms);
>2) Middle tier has four components:
>2.1) An API layer that offers the front end a way to access the middle tier;
>2.2) A VFP based component (contains the heavy data manipulation);
>2.3) A .NET based component (don't know how much it will contain);
>2.4) A data access component which will allow access to Oracle in future.
>3) The back end is SQL Server with a future possibility of Oracle.
>
>Question: With what tools should the API layer and the data access layer be developed in order to maximize speed at runtime, VFP or a .NET language?
>
>TIA, Alex

You can try COM interop or using EnterpriseServices (COM+) to talk to the VFP COM Components. Web Services might be slow. Each request has to be packaged up in a SOAP request and unpackaged on return.