ZDaemon - Classic Online Multiplayer Doom

The ultimate first person shooter experience, based on the original classic Doom from id Software! ZDaemon lets you play with other players just like any modern FPS, whether they're across the street or across the globe.
Create a ZDaemon account, and you'll be able to keep track of your progress, gaining experience and levels simply by playing the game. Up to sixteen players can join in a match, against monsters or each other. ZDaemon supports favorite modes like Cooperative, Survival, Deathmatch, Team Deathmatch, and Capture the Flag, and can be played on thousands of maps designed for Doom, Doom II, and Heretic, including the originals.