[83457]

My recollection of this is...The person who leaked HL2 actually hacked into Valve's network and could not find anything that could be considered a game, just a bunch of tech demos and assets (I downloaded and played the E3 demo). He essentially announced that Valve was lying to the public about their progress on HL2 right before the originally scheduled release date and delay. I believe Steam was announced before the leak, and released well before HL2 release.

[electromagnetic]

It was released well before the HL2 release, because I remember having HL2 pre-downloaded for day of release.

[Maxious]

Steam in various forms had existed for a while; firstly in 2002 as a more efficient distribution engine for Counter Strike then to provide authentication and matchmaking for the HL1 multiplayer after Valve's publisher Sierra planned to turn off their servers in 2004. They offered upgrades for all old HL1 cdkeys to a steam account and then started selling their games (I think Counter Strike: Condition Zero was the first new release) through it too... which wasn't appreciated by Sierra: http://en.wikipedia.org/wiki/Valve_Corporation#Valve_vs_Vive...