I did also benchmark against the XS module, and my module is quite slow in comparison (duh) unless the strings are equal, where my short circuit (return 0 if $word1 eq $word2) lays the smack down, in the parlance of our times.

for your information, here are my benchmark results:

joshs-Computer:~/leven josh$ perl levenshtein.pl foo fee
The distance between foo and fee is 2
         Rate   cpan   mine cpanxs
cpan   80.6/s     --   -16%   -97%
mine   95.5/s    18%     --   -97%
cpanxs 2844/s  3430%  2879%     --
joshs-Computer:~/leven josh$ perl levenshtein.pl foo foo
The distance between foo and foo is 0
         Rate   cpan cpanxs   mine
cpan   83.2/s     --   -97%   -98%
cpanxs 2849/s  3325%     --   -31%
mine   4109/s  4840%    44%     --
joshs-Computer:~/leven josh$ perl levenshtein.pl foo bar
The distance between foo and bar is 3
         Rate   cpan   mine cpanxs
cpan   81.2/s     --   -15%   -97%
mine   95.4/s    18%     --   -97%
cpanxs 2829/s  3385%  2865%     --
oshs-Computer:~/leven josh$ perl levenshtein.pl 1234567890 0987654321
The distance between 1234567890 and 0987654321 is 10
         Rate   cpan   mine cpanxs
cpan   9.35/s     --   -24%   -99%
mine   12.3/s    31%     --   -99%
cpanxs 1782/s 18966% 14410%     --
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