Apparently Antonio Linares announce the availability of AdoRDD on 26 April 2007 and since then there have been 169 follow-up posts. There has also been some discussions on AdoRDD in the Harbour Main Developers List as well
This is what Antonio Linares posted quoted verbatim
Actually this code is already working:
USE test.mdb VIA "ADORDD"
It has already been tested with Access and MySQL, but it should work with any DataBase engine that supports ADO.
Fernando Mancera (Updated 20/1/2010)