Hi Hilmar,
I cann't speak for other distributions of Linux, but Postgres runs great right out of the box after a RedHat Linux Install. I use the ODBC driver provide at the postgres site to make my connection to postgres. It works great with remote view and especially with VFP8 CursorAdapter. I also connect using the ODBC via DNSless connection and use VFP's sqlexec().
The postgres development team is working on a native windows port of postgres that is currently planned for release within the next six month. In reading some of the emails from the postgres mailing list, to which I have subscribed, the postgres team is impressed with the functionality of Microsoft's OLE DB provider and are working to on an OLE DB provider for postgres that would work both in the tradional VFP setting as will as with .NET. Currently, postgres does not have an OLE DB provider.