The misc/bsdiff port
bsdiff-4.3 – binary patch tools
Tools for building and applying patches to binary files.
The tools included are:
o bsdiff - Binary patch generation
o bspatch - Binary patch application
These tools are analogous to diff(1) and patch(1) but deal specifically
with binary files. The binary diffs produced are significantly smaller
than those produced by similar tools (free and commercial).