KDX Game Browser
From DoomWiki.org
KDX Game Browser is a client working with The Universal Master Server (UMS). The KDX Game Browser implements a TCP/IP based communications protocol for querying the master server for a list of KDX based game servers. Each game server is then queried separately for all certain game parameters, level settings, etc. These details can then be easily loaded into the KDX Frontend to synchronize between the players, followed by an online Doom match.