.ACF File Extension

File used by Valve Steam, a software package used for downloading games; saves information related to the downloaded software and is used for the original download as well as game updates.

ACF files are used by newer versions of the Steam content delivery system. Older versions use .GCF and .NCF files.

Data file that describes a character created for Microsoft Agent, an interactive animation program; contains character data that can be loaded over the HTTP (or Web) protocol; saved along with a corresponding .ACA file, which contains animation data for the character.

NOTE: Microsoft Agent has been discontinued with the release of Windows 7.

Convolution kernel file created by Adobe Photoshop, an image-editing program; contains a NxN kernel matrix of values used to manipulate the neighboring pixels surrounding a given pixel; can contain positive and negative values as well as mathematical expressions.

Convolution kernel matrixes can be used for blurring, sharpening, embossing, or performing other raster graphic operations to an image; once saved in an ACF file, they can be repeatedly applied to images.