Gearhead Caramel’s Story Generator
I think story generators in the Gearhead series are currently the most complete story generator that is least talked about. While there are many exciting new approaches that people are trying, Joseph Hewett has had working procedurally generated plots in his games for well over a decade.
He’s recently written a blogpost about the story generator in the Winter Mocha release of Gearhead Caramel. It’s a good summary of his approach and how the current and previous Gearhead story systems work.
http://www.gearheadrpg.com/2018/02/26/winter-mocha-random-story-generator-propps-ratchet/