Bughouse & Crazyhouse
BugAssistant – BPGN viewer for examining bughouse databases.
Bughouse.net – Every darn thing you need to know about bughouse along with software to help you play it better.
d2d4 – Bughouse tutorials, annotated games, and a discussion forum.
Deep Bug – Bughouse-playing chess engine.
Ebenfelt’s Bughouse Page – Rules, strategy, links, server comparisions, etc.
ErrantFischer’s Bughouse Page – Bughouse strategy, tactics, & featured games.
Sjeng – A computer chess engine that plays bughouse & crazyhouse.
Sunsetter – Another bughouse / crazyhouse engine — ability to play on a chess server.
Thief – A special online graphical interface made mainly for bughouse.
Wild Game 24: Bughouse – Rules and strategy, and how to play on ICC.
Other Chess Variants
Bishops – Four-player variant you can play online with java applet.
Cardinal Super Chess – Chess on an 10×10 board with the addition of a new type of piece, the “Cardinal”.
Checkmates – Four player sets for sale.
Chessapeak Games – 4-player partnership chess.
Chess 2 – The “fool” and the “knave” join the rest of the pieces.
Chess Variant Applets – Play dozens of chess variants against a computer opponent.
Chess Variant Pages – Huge site with rules for TONS of chess variants.
Chexx – Two to six player hexagonal chess.
4-Player Chess – Four-player chess set for sale.
Global Chess – Futuristic version of chess played on two circular discs.
Go Chess – Variant on a 10 x 10 board. Play online with a java interface.
Gothic Chess Association – Rules, tournaments, and (soon) software for this variant. Played on a 10 x 8 board with some new pieces.
HexiChess – 3-d hexagonal chess.
Kung-Fu Chess – Chess is now an action game! An amusing, if not nerve-racking diversion. Play online instantly.
Losing Chess Strategy – How to lose your pieces efficiently in Suicide Chess.
Ministers Chess – Played on a 9 x 9 board with two queens, called “ministers”, one on each side of the king, creating a symetrical game. Sets / boards for sale, and you can join the “Ministers Club”.
Omega Chess – Played on a 10 x 10 board with two extra pieces, this variant has some GM support. See the game Judit Polgar played against Alex Sherzer.
Pi Team Chess – Interesting product intended mainly for children to develop teamwork and critical thinking skills.
Power Chess – Interesting idea: chess with one half of the board shifted one square over, creating two extra triangular squares on the middle edges. All is explained exhaustively here.
Progressive Chess – A thorough online guide to Progressive Chess, with each side making a progressively greater number of moves on each turn.
Quadlevel – 3-d chess (4 half boards stacked). Site includes downloadable quadlevel chess software, quad boards for sale, history of the variant, and of course the rules.
SpeedChess – Online chess with a reduced size board. Play against the computer or against an online opponent (if there are any).
Symmetrical Chess Collection – Dozens of variants, all symmetrical using only sliding pieces for the Zillions of Games platform.
TouchDownChess – Chess crossed with American football?
Trancendental Chess – FischerRandom-like variant. Organizes e-mail tournaments.
TriChess – Chess for three.
Trigon Chess – Selling a variety of chess & checkers variants, all for three players.
Tucan Chess – Bigger board & some new pieces.
World War Chess – Similar to chess, with military-themed pieces and some new twists.
Zillions Of Games – Software package allowing you to create almost any board game and be playing against an AI (or human) opponent immediately. Comes with hundreds of games (including many chess variants) built in, and more can be downloaded from their web site as people create them.