I have used Markov chains for a few fun projects, like this Markov chain headline generator (<a href="https://locserendipity.com/Markov_Headlines.html" rel="nofollow">https://locserendipity.com/Markov_Headlines.html</a>), and a Markov generator based on a certain someone's Twitter feed (<a href="https://locserendipity.com/Markov_Trump.html" rel="nofollow">https://locserendipity.com/Markov_Trump.html</a>), but this looks like a good resources for more serious applications.