Excite offers a number of Java-based games, including Reversi. Excite also has arcade games, card games, casino games, trivia games, and word games.

Simple graphics, but nice touches such as animation, undo, and seven levels of difficulty make this Java implementation of Othello a winner.  Requires Java 

One of the strongest Reversi applets on the Internet, this program plays well, looks great (with 3D board representation and move look-ahead), and even features decent sound. Very fine.  Requires Java 

Play free online games including Backgammon, Battleboats (Battleship), Chess, Checkers, Othello, Pente, and more - over 35 different games and variations. No Java, no downloads. Tournaments and extensive message boards are part of this active community.

A large selection of unusual online board games, including Othello All games require Java, and most can be downloaded for offline play.

Play Reversi online at the zone. Also available: Backgammon, Checkers, Chess, Go, and more.

Play Othello (or Reversi) across the Internet. Allows your other friends to view game in progress using special spectator mode. Chat with your friends real-time. Allows off-line playing with human or computer player too. Requires download of a free Windows 95/98/NT client.

Yahoo's board game offerings include Backgammon, Checkers, Chess, Go, Mah Jongg, and Reversi, as well as a number of popular card and word games. All games require Java.