Fractal Image Format

FIF (Fractal Image Format) is a raster image format that uses lossy fractal compression. It is apparently a proprietary format developed by Iterated Systems.

Identification
FIF files begin with bytes.

Software

 * Genuine Fractals Photoshop plug-in

Sample files

 * http://users.senet.com.au/~mjbone/Fractals.html → River.fif

Links

 * Wikipedia: Fractal compression