WordFrequency is a free program that outputs word and trailing word frequency information for a given input file.
A trailing word is any word that follows immediately after another in the text. WordFrequency can also be used to generate text of a certain format/style from a given starting word, based on the original input text.
WordFrequency should be of a similar format and fairly readable thanks to the frequency analysis.
Some inputs work well with WordFrequency, such as giving lots of rhyming poetry often results in new nonsense poetry that rhymes.
