Yamashita Hiroshi, Japan. He is also the author of the Shogi program 'YSS' and the Amazons engine 'Yamazon'
version: v5.99 (2007) level 'ponder' (ca 20s per move) and v6.34 (2008) which plays faster (level 'strong': ca 10s per move) but seams to be a little bit stronger on 19x19 Go - both versions are apparently weaker on 19x19 Go but much stronger on 9x9 Go with '+1ply' setting (= approx. 1 min. per move).
info: Hiroshi Yamashita about his program: The name of "Aya"(Chinese character) was inspired by "Beautiful end position that was made by collaboration between white and black" and Japanese "Aya" means mislead :-) - Aya search 4-5 plies in 19x19, and 6-7 plies in 9x9. Nodes per second is 200-300 nps in 19x19 and 500-600 nps in 9x9 (Pentium3M 1.13GHz). Evaluation function includes strings capture and some connections search. Life and death, eye-shape recognition are static. Moves are generated from simple stone shape pattern. Life and death, eye-shape and connection points from evaluation function are also generated. The moves around weaker and bigger stones get higher temporary value. Number of moves limit each 1,2,3,4,5,6,7 depth are 50,20,10,10,10,10,10. In first depth(root) and two depth all moves are generated. And over 3 depth, Aya generates only nearby last moves and around getting weak stones by last opponent move. These idea are mainly from Haruka, Japanese strong Go program's explanation (http://www.cs.ualberta.ca/~games/go/index.html).
link: Hiroshi's Computer Shogi and Go
Rémi Coulom, Associate Professor (Maître de Conférences) of computer science at the Université Charles de Gaulle, Lille, France. He is also the author of the free chess engine 'The Crazy Bishop', a LOA engine 'Lola' and the free Elo-rating tool 'Bayeselo'. Rémi Coulom is currently board member of the ICGA as Programmers Representative and did the web site development for the ICGA tournament database.
version: CrazyStone0005 (first to maximize probability of winning instead of expected territory!) was the version that won gold running on a dual Opteron 275 (4 CPUs at 2.2 GHz) in 9x9 Go at the 11th ICGA Computer Olympiad 2006, Turin. Until 2007 this was the strongest 9x9 Go engine available and free!
info: since 2006 CrazyStone won many international tournaments and very often ends first in 9x9, 13x13 and 19x19 KGS tournaments - European Go Congress 2008, Leksand: CrazyStone was 1st in 19x19 Go and 2nd in 9x9 Go. - CrazyStone has improved a lot since 2006 thanks to the incorporation
of pattern knowledge into its search algorithm. Patterns help to
improve the quality of random simulations, and are used to prune bad
moves. Details of this algorithm can be found in a paper presented at the Computer Games Workshop.
links: main site with details+links / FIT2008: CrazyStone won an 8 stone handicap game against Kaori Aoba (4p)! / Report on ICGA Olympiad Amsterdam 2007 and Interview with Rémi Coulom about MC-TS in ComputerSchach&Spiele (german)
Frédéric Boissac + Éric Marchand, France.
version: win-gtp-22.214.171.124 (level 7)
info: 19x19 Go: 3rd in European Go Congress 2001, Dublin / 9x9 Go: 1st in 8th KGS Tournament (Nov. 2005)
link: for info and download