For the people that will be doing the implementation of System.Data.SqlClient with FreeTDS: There are 2 Java/JDBC ports available (http://www.freetds.org/software.html). I guess they work without p/invoking against the platform libs. Will you port parts of these to C# and use them? I think this would be cool, as it would mean the class lib wouldn't have one new dependency on native code. Johannes