After almost a painstaking 9-year old development, Valve has officially released Team Fortress II which was bundled along with the Orange Box on October 10, 2007. Actually, it is actually an evolution of the core Team Fortress gameplay, not any sequels of either Team Fortress Classic (or 1.5) or the Quake version. Earlier versions of TF2 (Brotherhood of Arms) featured realistic modern military and commander style of gameplay, as shown in the 99's E3 and also the game was promised to be released in January 2001.
Source: Tech ARP