EDelta is a fast XDelta-style binary differ, but optimized for executables which have a very systematic way of changing between versions. It has not been thoroughly evaluated so far, but on one example (two versions of Vim) it produces a 30kB delta where XDelta needs 250kB. My personal use for edelta is to quickly deploy Linux kernels from my development-laptop to my test-machines, especially when working over my slow ADSL line at home. I frequently see factor of 100 speedups compared to shipping the whole file.