The Nalimov/Syzygy, etc tablebases are, as far as I know, computer databases that store all the possible possitions in the board, with the best moves and the outcome of the game, assumming both players work perfectly.
Is there still work on them? I think all the positions of 7 or less pieces are solved by now, but I don't know if there are computers out there at the moment, calculating positions and adding them to these databases.