12TB Steam 'teraleak' dumps a decade of lost Valve prototypes and cut content

A 12TB data dump of Valve's defunct Steam2 content servers is circulating via BitTorrent, exposing what appears to be every version of every game uploaded to Steam between 2003 and 2013. The collection includes public release builds alongside previously unseen pre-release, prototype, and playtest versions of titles from Valve and third-party publishers, including cut Portal 2 content and hints of Half-Life 2: Episode 3.

The leak cuts off in 2013 because that is when Valve replaced Steam2 with the SteamPipe content distribution system, moving from a proprietary file format to standard HTTP file trees. Early versions of some pre-transition games had been considered lost by archivists, surviving only on aging local machines.

Longtime Valve watcher and dataminer Gabe Follower said he verified the content was obtained through a publicly accessible API endpoint. Spanish-language Valve streamer Scolcer said the data came from a site that was fully public, with no passwords or protection, "hidden in plain sight." Valve seems unlikely to purge the torrent from the Internet, Ars Technica reports.