FreeTDS is a set of libraries for Unix and Linux that allows your programs to natively talk to Microsoft SQL Server and Sybase databases.

Technically speaking, FreeTDS is an open source implementation of the TDS (Tabular Data Stream) protocol used by these databases for their own clients. It supports many different flavors of the protocol and three APIs to access it. Additionally FreeTDS works with other software such as Perl and PHP, providing access from those languages as well.

FreeTDS has many possible uses. It has been used by Unix/Linux webservers to present data stored in SQL Server to the web, to port SQL Server database code from NT to Unix, to import data into SQL Server from a Unix source, and to provide database access on platforms (such as realtime systems) that have no native drivers.

The FreeTDS C libraries are available under the terms of the GNU LGPL license, consult the COPYING.LIB file in the distribution for details.