A compressed file library (CFL) is designed to work as a virtual file system for programs, especially for games. By compressing various game resources into one file, it is able to keep the number of file accesses down. The resources can also be encrypted in the CFL. CFL is used by X-Forge, the multi-platform wireless 3D game engine developed by Fathammer Ltd. It is also used by IMVU for its 3D character models and accessories.