Computer Dictionary of Information Technology

Microsoft Data Access Components

(MDAC) Microsoft's umbrella term for their ActiveX Data Objects (ADO), OLE DB, and Open Database Connectivity (ODBC) libraries. Together, these provide access to a variety of data sources, both relational (SQL) and nonrelational. MDAC is the technology that supports Universal Data Access, Microsoft's strategy for providing access to information across the enterprise.

http://msdn.microsoft.com/library/en-us/mdacsdk/htm/mdacstartpage1.asp.