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Binary diff/patch utility version 4.3, written by 
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Copyright 2003-2005 Colin Percival <cperciva@freebsd.org>
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bzip2/libbzip2 version 1.0.4 of 20 December 2006
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Copyright (C) 1996-2006 Julian Seward <jseward@bzip.org>
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This is a quick native Win32-Port by 
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Andreas John <dynacore@tesla.inka.de>
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Quick overview from the homepage of these tools:
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http://www.daemonology.net/bsdiff/
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Binary diff/patch utility
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bsdiff and bspatch are tools for building and applying patches to binary
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files. By using suffix sorting (specifically, Larsson and Sadakane's
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qsufsort) and taking advantage of how executable files change, bsdiff
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routinely produces binary patches 50-80% smaller than those produced by
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Xdelta, and 15% smaller than those produced by .RTPatch (a $2750/seat
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commercial patch tool). 
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These programs were originally named bdiff and bpatch, but the large
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number of other programs using those names lead to confusion; I'm not
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sure if the "bs" in refers to "binary software" (because bsdiff produces
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exceptionally small patches for executable files) or "bytewise
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subtraction" (which is the key to how well it performs). Feel free to
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offer other suggestions. 
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bsdiff and bspatch use bzip2; by default they assume it is in /usr/bin. 
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bsdiff is quite memory-hungry. It requires max(17*n,9*n+m)+O(1) bytes of
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memory, where n is the size of the old file and m is the size of the new
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file. bspatch requires n+m+O(1) bytes. 
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bsdiff runs in O((n+m) log n) time; on a 200MHz Pentium Pro, building a
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binary patch for a 4MB file takes about 90 seconds. bspatch runs in
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O(n+m) time; on the same machine, applying that patch takes about two
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seconds. 
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Providing that off_t is defined properly, bsdiff and bspatch support
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files of up to 2^61-1 = 2Ei-1 bytes.
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