PPF-O-Maker

This application enables you to make Playstation Patch Format files (V1-V4).
One possible use is to make changes to an iso file (which remains the same size) and instead of posting the full iso you just make a PPF patch between the original and edited iso and distribute that instead.

This will work as long as both images have the same size. PPF V1+V2 are for small files (32bit limit), V3+V4 are the more modern formats.