You're correct that the VFP ODBC driver is not thread safe. I believe the VFP OLE DB driver is thread safe.

I can't speaking for using it with WCF. I had to use it for an app a long time ago, before WCF came out.

You might want to try to contact Rick Schummer - I think I've read blog and tech forum entries where he seemed to know a good amount about the driver.