anchor.diff:  count,license
  +2,"zlib/libpng"
   1,"zlib"
   13,"WTFPL"
   1,"WTF"
  
positive.code: 4,"GPLv3+"
  23,"GPLv3"
  2,"GPLv2+"
  7,"GPLv2"
  7,"GPL3"
  1,"GPL2"
  1,"GPL-3.0"
  29,"GPL-3"
  25,"GPL-2"
  22,"GPL"
  1,"GPL v3.0"
  1,"GPL v3"
  1,"GPL v2"
  1,"GPL Lv.3"
  1,"GNU"
  1,"GNU LGPL v3"
  1,"GNU Lesser General Public License, Version 3.0"
  1,"GNU GPLv3"
  1,"GNU GPLv3 and AGPLv3"
  
negative.code: 2,"UNLICENSE"
  1,"To be decided"
  1,"The Ruby License"
  1,"The BSD 3-Clause License"
  1,"THE (extended) BEER-WARE LICENSE"
  6,"Simplified BSD"
  1,"See LICENSE."
  1,"Ruby's"
  1,"Ruby's or GPLv2 or later"
  7,"Ruby"
  1,"Ruby License"
  2,"R2CORBA"
  1,"PUBLIC DOMAIN"
  30,"Public Domain"
  4,"Public domain"
  1,"Proprietary"
  1,"PayPal SDK License"
  