bsdiff ------ This package provides a pair of tools for building (bsdiff) and applying (bspatch) binary patches. When applied to two versions of the same executable the patches produced are significantly smaller than those generated by other binary diff tools. Bsdiff and bspatch were originally written as part of the author's FreeBSD Update tool, where they provide an average 50-fold reduction in the bandwidth used to distribute binary security updates to the FreeBSD base system. Since that time it has been incorporated into a large number of products, including Apple's OS X. The price to pay for the efficient delta compression of executable code comes in speed and memory usage: Bsdiff is many times slower than alternatives, and requires memory equal to 17 times the size of the "old" input file. The website for bsdiff is .