in reply to How to connect to MS SQL Server from Unix
If you decide to consider ODBC ...
2 or 3 years ago I used ODBC-to-ODBC Bridge product for Unix to Windows for MS SQL Server (or other ODBC source defined on the Windows side). Good support for Perl DBD::ODBC module. This ODBC vendor knows about Perl, where another vendor only wanted to discuss C interface.
http://www.easysoft.com/products/data_access/odbc_odbc_bridge/index.html
Bill