xdelta - Binary delta generator

Xdelta is a program designed to compute changes between files. These
changes (deltas) are similar to the output of the "diff" program in
that they may be used to store and transmit only the changes between
files. However, unlike diff(1), the output of xdelta is not expressed
in a human-readable format.

Xdelta uses a fast, linear algorithm and performs well on both binary
and text files.