Valve announcement
"The first 64-bit Valve games released will be native 64-bit versions of Half-Life 2 and Lost Coast, and have been developed to take advantage of AMD Athlon? 64 FX processor-based systems - the ultimate 64-bit gaming platform for PC enthusiasts.
The 64-bit versions of these games are being offered to all Half-Life 2 owners via Steam?, Valve?s online platform for delivering games and digital content directly to users around the world"
"The first 64-bit Valve games released will be native 64-bit versions of Half-Life 2 and Lost Coast, and have been developed to take advantage of AMD Athlon? 64 FX processor-based systems - the ultimate 64-bit gaming platform for PC enthusiasts.
The 64-bit versions of these games are being offered to all Half-Life 2 owners via Steam?, Valve?s online platform for delivering games and digital content directly to users around the world"