less active, and Jiri Dufek is in charge of the book. History Vasik Rajlich started working on his chess program at the beginning of 2003. The first Rybka beta was released on December 2, 2005. The appearance of the free Rybka 1 beta and the first commercial version, Rybka 1 end of 2005 was a sensation, and Rybka soon became the dominating program leading rating lists by a huge margin. Tournament participations In January 2004, Rybka participated in the 6th Programmers Computer Chess Tournament (CCT6) event, placing 53rd out of 54 competers, losing 5 games, drawing 3, and beating the last-place finisher who had 0 points (Tohno). In April 2004, Rybka participated in Chess War V conducted by Olivier Deville, finishing 23rd in the D Division. In April 2004, Rybka participated in the Swiss System Season 3 by Claude Dubois, scoring 6 wins, 6 losses and 6 draws in the Top 200 to finish 71st. Rybka participated in Chess War VI finishing 42nd in the D Division. Rybka participated in Chess War VII finishing 48th in the C Division. Rybka participated in AEGT round 3, scoring 89 wins, 28 losses and 15 draws. In December 2005, Rybka participated in the 15th International Paderborn Computer Chess Championship. Rybka won the tournament with a score of 5½ points out of 7, ahead of other engines such as Gandalf, Zappa, Spike, Shredder and Fruit. On CCT8 in February 2006, Rybka won with a score of 8 out of 9, going undefeated. In the April 2006 PAL/CSS Freestyle main tournament, an unaided Rybka 1.1 took first place. In the final tournament, Rybka 1.1 finished in second and third place, behind Hydra. In the 6th Leiden ICT in May 2006, Rybka won with a score of 8½ out of 9, ahead of Sjeng, Gandalf and Shredder. At the 14th World Computer Chess Championship in Turin, Italy in May 2006, Rybka, playing under the name Rajlich, finished second, tied with Shredder, after Junior, the winning 2006 World champion. In the June 2006 PAL/CSS Freestyle main tournament, the Rybka team, playing under the handle Rajlich, tied for first place with Intagrand. In the final, the Rybka team took clear first place, a point ahead of the field. All 8 qualifiers for to the final were Rybka users. In the 2006 Dutch open computer chess championship, Rybka 2.2 finished in first place with a perfect score of 9