Doom Connector

Free lobby-based matchmaking service specialized for several popular Doom multiplayer ports such as ZDoom, Skull Tag, ZDaemon, Doom Legacy, csDoom and JDoom (Doomsday). Allows you to see all public servers from all doom mastservers, but also allows you to launch private peer-to-peer games. Includes IRC-like chat, buddylist, filetransfers and offline messages and shows your pings to all servers and other players. Developed by Pascal vd Heiden, hosted and maintained by several others.