Open GCF File
A GCF extension file is a cache file used by Valve's Steam game distribution software.
Steam is a cloud service for the purpose of digital video game distribution from developer Valve.
Available since 2003, initially as an independent developer, as a way for Valve to provide automatic updates for their games.
Some years later it was expanded to include games from third-party publishers.
Steam is available for all the most common operating systems.
In this case, the GCF file contains a virtual file system that can include file fragments, metadata, checksums, and other information relevant to the game.
It is also, to GCF files, given storage use of downloaded games and game updates from Valve's distribution service.
GCF stands for 'Game Cache File'.
Open the GCF files
GCF files are not intended to be manually opened or altered by the user.