There is a link about the game, which is the western standard game with a bit of the Japanese Shogi flavor in terms of captured pieces, instead of leaving the game completely, being able to return during a "trading of hostages", whereby pieces can be dropped as in Shogi. It complements standard play very well, and makes for a very interesting game. Look at www.chessvariants.org/difftaking.dir/hostage.html
to see some details on the game, or check out D. Pritchard's Popular Chess Variants to read about it. I got a chance to play it (it is similar in the dropping aspect to Loop Chess) and so would not be such a challenge to modify the programming, I would guess. And the gameplay is marvelous.