This site provides technical articles, sample code, and other resources for SQL Server Native Client and other data access technologies. This site also provides links to download the most recent stand-alone release of the Microsoft Data Access Components (MDAC).
This site contains the latest Windows Data Access Components (Windows DAC) SDK documentation. Windows DAC is the version of the data access components (called MDAC in earlier versions) that is included in Windows Vista and Windows Server 2008.
The Window DAC SDK includes documentation for ActiveX Data Objects (ADO), OLE DB, and Open Database Connectivity (ODBC).