Look at SQL Server Native Client Programming

SQL Server Native Client combines the SQL OLE DB provider and the SQL ODBC driver into one native DLL. It also provides new functionality above and beyond that supplied by the Windows Data Access Components(formerly Microsoft Data Access Components). SQL Server Native Client can be used to create new applications or enhance existing applications that need to take advantage of features introduced in SQL Server 2005, such as multiple active result sets, user-defined data types etc.