This is very cool. And now even more Racket on HN's front page. I will look at the code later.
For those interested, variable-order Markov chaining is different form traditional Markov models. I studied the latter in computational linguistics courses; they are a right of passage in stastical models for CL/NLP work. I was wondering how it was a good idea to model passwords, even pseudorandomly with Markov chains, but VO Markov chains are somewhat different.
For the uninitiated, like myself.