MIT Professor Nick Montfort has announced the launch of his new digital narrative authoring system, Curveship. The system models not only the fictional world and its characters, but the narrative discourse as well; it can rearrange the story events or structure responses from a specific character's viewpoint.
I hope the system will be useful for teaching about narrative theory and for research in AI, computational creativity, and related areas. But its primary purpose has always been the creation of new types of electronic literature.
Curveship is built using Python and is currently free to download