This package supports the analysis of bigrams that appear in text using Fishers exact test, the log likelihood ratio, Pearsons chi-squared text, and the Dice Coefficient. BSP is designed so that you can easily add your own statistics. It is written in Perl and is freely available.
TLA-team: Pedersens ngram statistics package provides many easy-to-use statistics on character and word ngrams. It is written in PERL and can be downloaded.