Knights and pawns are being brandished in the rarified world of computer chess, with program Rybka and its developer Vasik Rajlich stripped of the world title on a charge of plagiarism.
According to Chessvibes, the controversy has been simmering since February this year, when Rybka lost in a game against a rival program, Houdini. In response to accusations that Rybka used code from other chess engines, the International Computer Games Association put together a panel to investigate.
Now, the ICGA has decided that Rybka was cloned from the open source Crafty and Fruit chess programs, with its panel deciding to strip Rajlich of his World Computer Chess Championship titles for 2007 to 2010, and his shared second place for 2006.
The letter from the ICGA, published by Chessvibes, says that although Rajlich repeatedly denied plagiarizing other programmers’ work, he didn’t offer “any kind of defence to the allegations”.
Moreover, the committee has accused Rajlich of breaching the open source licenses of both Crafty and Fruit, by basing Rybka on these open-source programs, but not offering the source code to users. ®