Here is my list (Deep Fritz excluded).
Please let me know if there are other engines that can use 8 cores.
As I will be running another 8 core Swiss in about a week's time, engine authors are welcome to email me their latest developmental version if they'd like to see it participate.
Komodo (latest) 64-bit 8CPU
Stockfish (latest) 64-bit 8CPU
Houdini 4 64-bit 8CPU
Fire 4 64-bit 8CPU
Gull 3 64-bit 8CPU
DON (latest) 64-bit 8CPU
Equinox 3.30 64-bit 8CPU
Critter 1.6a 64-bit 8CPU
Rybka 4.1 64-bit 8CPU
Bouquet 1.8 64-bit 8CPU
Sting 4.7 64-bit 8CPU
BlackMamba 2.1 64-bit 8CPU
Elektro 1.2 64-bit 8CPU
Naum 4.6 64-bit 8CPU
Chiron 2 64-bit 8CPU
Protector 1.7.0 64-bit 8CPU
Hannibal 1.5x5 64-bit 8CPU
Texel 1.05a7 64-bit 8CPU
Hiarcs 14 8CPU
Senpai 1.0 64-bit 8CPU
Deep Shredder 12 64-bit 8CPU
Deep Junior Yokohama 64-bit 8CPU
Spike 1.4 Leiden 8CPU
Spark 1.0 64-bit 8CPU
Fizbo 1.31 64-bit 8CPU
Zappa Mexico II 64-bit 8CPU
MinkoChess 1.3 64-bit 8CPU
Gaviota 1.0 64-bit 8CPU
Arasan 17.4 64-bit 8CPU
Onno 1.2.70 64-bit 8CPU
Deep Sjeng WC2008 64-bit 8CPU
Tornado 6 64-bit 8CPU
Crafty 24.1 64-bit 8CPU
Cheng4 0.36c 64-bit 8CPU
Scorpio 2.7.6 64-bit 8CPU
EXchess 7.31b 64-bit 8CPU
Octochess r5190 64-bit 8CPU
BugChess2 1.9 64-bit 8CPU
RedQueen 1.1.97 64-bit 8CPU
Alfil 13.1 64-bit 8CPU
Hamsters 0.7.1 8CPU
Nebula 2.0 64-bit 8CPU
Arminius 2014-01-18 64-bit 8CPU
Delphil 3.2 64-bit 8CPU
Myrddin 0.86h 64-bit 8CPU
FireFly 2.7.0 64-bit 8CPU