GTADS is short for Grand Theft Auto Dedicated Server. GTADS was originally written as a chat server/client framework to allow GTA1 players to play each other without having to deal with direct game ports over the internet.
GTADS currently plans to support a wide range of LAN-based games such as GTA 1, GTA 2, Twisted Metall 2 and Doom. GTADS is based on Java, so it can run on a wide variety of operating systems and hardware.