British bingo runs in your browser and uses 3 by 9 boards. The game simulates the other players. Players make mistakes and chat. Players leave, join, and re-join between and during games. You can have over 10,000 players. You can hear the players and the caller talk. You can change the sizes to fit a small screen
Bitfighter is a game that feels a little like Asteroids on steroids. It's a multiplayer space-based combat and strategy game, featuring customized ships, multiple game modes, cool retro graphics, and smooth network play. It also includes a full featured level editor, Lua scriptable bots, and other cool features. It has a very active development team, so the game keeps improving.
garith is a game similar in spirit to BSD's "arithmetic" or TuxMath. The game asks you to perform a simple arithmetic operation within a certain time frame. It improves your skills by stressing the operations you get more frequently wrong or that longer to answer. The statistics are saved/restored across games, so that each game is tuned for your current arithmetic abilities.