Vipers
Vipers! A multi-player arcade game. * quite simple but very addictive! * the more players, the more fun * non-violent play for children and adults * many players, but no need for many connected computers * play against friends, relatives, or against computer opponents Each player drives a... The goal of each Vipers player is to score points by crossing gray gaps, avoiding dangerous objects, capturing food, and eliminating other players. ... This is why all the players can fit on a single keyboard.
http://www.cs.put.poznan.pl/mkomosinski/vipers/VipersInstall.exe - 1Mb - Download - Screenshot

Titan Poker 2006
Titan Poker has just launched as the most exciting and innovative venue for playing online poker. For every hand players play at Titan Poker, and which generates rake, they earn Stars - Titan Poker's unique player points. Players receive bonuses based on the Stars they've earned. ... The more new players you help sign up at Titan Poker, the more cash you'll earn. ... Players can also win huge, progressive Jackpot Tournaments at Titan Poker. ... What's more - the time you can play for free is UNLIMITED!
http://www.real-3d-games.com/titan/titan_poker.zip - 1Mb - Download - Screenshot

Cubewar2003
Cubewar2003 is a 3D worms clone for two players that takes place in a cubular world in space. Every player has six bases and must destroy the bases of the other player. The players shoot after each other and not simultaneously. You shoot from the point of view of the different bases.
http://www.muenster.de/~dambergj/cube2003.zip - 66Kb - Download - Screenshot

Internet Backgammon
This is a two-player Backgammon game, that is, it has no human-against-computer mode. The two players can be sharing one computer's keyboard, mouse and monitor, or can be using two computers networked together over the Internet or any network with TCP/IP. ... The game includes a help file suitable for players new to Backgammon and experienced players alike. ... Sound effects are also included with the game. ... No separate server is required - the game is independent.
http://www.en-consult.ca/files/ibv102.zip - 5Mb - Download - Screenshot

Ten Thousand Dice
Ten Thousand Dice - A Game of Temptation and Chance for up to 6 human or computer players. The game is played with six dice, and is a race to score at least 10,000 points. You can play with any combination of human or computer players, and with the registered version, remote network players. ... The game continues until one of the players stays with 10,000 points or more in the bank. ... Once this happens every other player is given one final turn to try to bank more points than any previous player.
http://www.enwsoftware.com/Ten_Thousand_Dice/Download/10kd240.zip - 1Mb - Download - Screenshot

Shogo-Coop
Shogo-Coop is the ultimate in cooperative mods. It allows up to 5 players to play cooperatively through each one of Shogo's single player levels. Each player is able to read the story as it progresses, watch in-game cutscenes, and interact with game characters just like they could in single player. ... Levels and artificial intelligence have been enhanced to be challenging for any number of players that the mod supports. ... This is dynamically determined based on the number of players currently connected.
http://members.cox.net/tchang875/shogocoop.zip - 1Mb - Download

Double Happy
Double Happy is a social Tennis Doubles event organizer. It is designed to make it simple (and even fun) to run social doubles events for Tennis, Badminton, Table Tennis, or any activity where 2 people play as partners against 2 others. A typical scenario. ... Double Happy will generate, round by round, a mix of players to be assigned to each court for up to 21 courts and 200 players. ... This allows you to add new players as they arrive, rest players if they request it, and generally react to whatever situation arises.
http://www.promato.com/doublehappy/dhsetup.exe - 511Kb - Download - Screenshot

Galacticards (Linux)
Galacticards is the new Addictive Card Based Space Strategy Game of Exploraiton and Expansion. In Galacticards, five players start out with a home world, some defensive ground units, and a hand of five cards with which they begin their struggle to become the largest species in space. ... Players must make choices every turn to improve their situation, or defend against possible raids from one of four other players, as well as pirates, space monsters and aliens. ... The final objective for each player is to have had the most members of their species throughout the game.
http://killerbeesoftware.com/kbsgames/demos/GCDemoLinux.tar.gz - 16Mb - Download - Screenshot

Galacticards (Windows)
Galacticards is the new Addictive Card Based Space Strategy Game of Exploraiton and Expansion. In Galacticards, five players start out with a home world, some defensive ground units, and a hand of five cards with which they begin their struggle to become the largest species in space. ... Players must make choices every turn to improve their situation, or defend against possible raids from one of four other players, as well as pirates, space monsters and aliens. ... The final objective for each player is to have had the most members of their species throughout the game.
http://killerbeesoftware.com/kbsgames/demos/GCDemoWin.exe - 16Mb - Download - Screenshot

Galacticards (MAC OSX 10.3+)
Galacticards is the new Addictive Card Based Space Strategy Game of Exploraiton and Expansion. In Galacticards, five players start out with a home world, some defensive ground units, and a hand of five cards with which they begin their struggle to become the largest species in space. ... Players must make choices every turn to improve their situation, or defend against possible raids from one of four other players, as well as pirates, space monsters and aliens. ... The final objective for each player is to have had the most members of their species throughout the game.
http://killerbeesoftware.com/kbsgames/demos/GCDemoOSX.tar.gz - 16Mb - Download - Screenshot