Judging by stack traces ado.net is talking tds directly. Mono's implementation is based off freetds. Ruby has tinytds and of course existing c and c++ programm

Judging by stack traces ado.net is talking tds directly. Mono's implementation is based off freetds. Ruby has tinytds and of course existing c and c++ programmers can use the freetds library which works on Unix and Windows. The freetds community might be small but it is very active.