SpamBayes includes the unmodified gocr 0.46 binary from:

  http://www-e.uni-magdeburg.de/jschulen/ocr/gocr046.exe
  md5sum: 31966271f23293033728e8b5a4ccb4fa

gocr is distributed under the GPL - please see:

  http://sourceforge.net/projects/jocr

for more information on gocr, or:

  http://spambayes.org

for more information on spambayes.
