Steam

Steam is a digital distribution, digital rights management, multiplayer and communications platform developed by Valve Corporation. It is used to distribute a large number of games and related media entirely over the Internet, from small independent efforts to larger, more popular games. Steam is set apart from similar services primarily by its community features, completely automated game update process, and its use of in-game functionality.

Features

• Instantly access your favorite games - Over 1,100 games are available to purchase, download, and play from any computer. Check out the new releases, indie hits, casual favorites and everything in between.
• Join the Steam Community - Find someone to play with, meet up with friends, connect with groups of similar interests, and host and join chats, matches, and tournaments.
• Chat with your friends while gaming - See when your friends are online or playing games and easily join the same games together. Chat with your buddies, or use your microphone to communicate in any game.
• Automatic game updates - Hunting for patches and downloading from unorganized Web sites is so twentieth-century. On Steam, your games stay up-to-date by themselves. No hassles.

Note: Now requires OS X 10.6 or later

• Release notes were unavailable when this listing was updated.