This module implements the classic "Naive Bayes" machine learning algorithm.
It is a well-studied probabilistic algorithm often used in automatic text
categorization. Compared to other algorithms (kNN, SVM, Decision Trees),
it's pretty fast and reasonably competitive in the quality of its results.

A paper by Fabrizio Sebastiani provides a really good introduction to
text categorization:
http://faure.iei.pi.cnr.it/~fabrizio/Publications/ACMCS02.pdf