The WarZone is a gaming lobby for playing multiplayer versions of older DirectPlay 7 or earlier games.
While similiar in concept to GameSpy and the old, now defunct MSN Gaming Zone, it specializes in older games, is completely free and contains no ads, adware, or spyware.
Moreover, it includes the DirectPlay Router Bypass feature, allowing games to be played without disabling firewalls, changing router settings, or exposing your IP address to other players.