Shogi is a distant cousin of Chess. Unlike Chess, you may re-use captured pieces anywhere on the board anytime. It brings quite lot of additional complexities, and even after the defeat of Garry Kasparov in 1997, many considered that (at least top-level) human Shogi players have a great lead on computer Shogi engines.
The situation had changed dramatically when a newcomer Shogi engine called Bonanza, developed by a Japanese chemist Kunihito Hoki, won the 16th World Computer Shogi Championship. Bonanza appeared totally out of the blue —- Hoki incorporated some new ideas developed in the field of computer Chess, and Bonanza beated existing engines with no mercy. Bonanza could even corner some professional Shogi players in 2007. Later Hoki released(but not strictly open-source) the source code of Bonanza, and the standard of computer Shogi has risen considerably since then. Finally, in the 1st Denousen last year, Kunio Yonenaga, long retired but possibly one of the greatest Shogi players in the history, was defeated by Bonkras, a clustered version of Bonanza developed by Eiki Itoh of Fujitsu.
The first match of Denousen this year was held yesterday between Kouru Abe, an 18-year old prodigy from Aomori, and Shueso, which finished in 5th at the 22nd World Computer Shogi Championship. I hoped a close game, but Abe could beat Shueso quite easily. Shueso somehow could not bring its ability into full play, to my great disappointment. Next weekend(Mar. 30), we will see the second match between Shinichi Sato, another young pro, and Ponanza, developed based on Bonanza by Issei Yamamoto of The University of Tokyo.
BTW, Debian already has the package of GPS Shogi, which won the 22nd World Computer Shogi Championship and considered by many the strongest Shogi engine available now (there is also gnushogi in Debian, but gnushogi is quite weak).
You may have fun with
$ xshogi -fsp gpsshogi
Unfortunately, we don’t have good modern GUI for Shogi yet…