Teamplay

The Battle Grounds
A modification for Half-Life based on the American Revolutionary War.
http://www.bgmod.com/

Firearms Half-Life
News, forums, screenshots and beta download for a Half-Life modification with 27 new weapons.
http://www.firearmsmod.com/

Grand-Theft
Team based half-life mod, which tries to get the flair of the crime scene.
http://www.grand-theft.net/

International Online Soccer
A mod in which players play soccer on opposite teams.
http://ios.planethalflife.gamespy.com//

Science and Industry
A teamplay modification for Half-Life, in which players assume the role of Security Officer in one of two rival corporations striving for domination in the cutthroat world of chemical weapons research and development.
http://si.planethalflife.gamespy.com//