The excellent bsdiff utility

Colin Percival wrote the very excellent bsdiff utility which makes very size-efficient binary diffs. Starting from there, it is not too difficult to write a script for making binary diffs of directory trees, files and directories added, removed or changed. It is the binary counterpart to diff -Naur. I named it dar after tar. In a test run, I made a binary diff between 1.5.0 1.5.0_01 of the JREs included in the JDK. The dar file is 1.5Mb. A bzip2ed tar file of the whole JRE at maximum compression is 25Mb. Feeback welcome.