Steam is the first full-featured broadband platform for the delivery and management of games and digital content, and has pioneered its broadband services to over 10 million customers with core titles such as Valve's Half-Life 2 and Counter-Strike.

"Activision has been a player on every major gaming platform dating back to the Atari 2600," said Gabe Newell, co-founder and president of Valve. "We're delighted to welcome them to Steam, and offer this legendary company's products."

"Our agreement with Steam enhances our current online distribution model by allowing us to bring our games to the broadest possible audience," said Dave Anderson, Activision's Senior Director of Business Development. "As broadband penetration continues to grow worldwide, offering our titles digitally to the millions of gamers connected through Steam makes sense to us."