In addition to DB-Library, SQL Server supports the Microsoft Open Database Connectivity (ODBC) call-level API. ODBC enables applications for Windows, Windows NT, and Windows 95 to access multiple data sources, including a wide range of relational databases and local indexed sequential access method (ISAM) data. In most cases, DB-Library and ODBC are equally capable of creating SQL Server client applications. ODBC enables applications to access more data sources. DB-Library provides equivalent functionality in multiple client environments, including MS-DOS. In addition, DB-Library provides specialized support for SQL Server, such as bulk copy, two-phase commit, and text operations.
Tools for developing ODBC applications are available in the Microsoft ODBC Software Development Kit, which is part of the Microsoft Developer Network Level II. The ODBC drivers for SQL Server and the ODBC drivers for Open Data Services gateways are included with Microsoft SQL Server.