Chess Databases
I have listed below the best chess databases that I have found so far. If anyone has found others that they like please do send them in.
The first group have opening explorers:
http://www.ficsgames.org/openings.html
http://www.365chess.com/opening.php
http://www.chesslab.com/PositionSearch.html
http://www.chessgames.com/index.html
http://gameknot.com/chess-games-database.pl?bd=19670682&fb=1&rnd=9820
The rest of them do not have opening explorers but are valuable none the less.
http://www.chessbites.com/Games.aspx?ps=1&p=0C23421055CCC555CC1C5CCCCCCCCCCCCC8BCCCCCCCCC7CCBBCCCBBB6789ACC6
http://ingo-schwarz.de/schach/icofy-base-schach