Curveship is an interactive fiction system that provides a world model (of characters, objects, locations, and things that happen) while also modeling the narrative discourse, so that the narration and description of the simulated world can change. Curveship can tell events out of order, using flashback and other techniques, and can tell the story from the standpoint of particular characters and their perceptions and understandings.

Lisp deserves its place as the first high-level programming language. There were other languages of the time which let programmers work at a higher level than they had before, but they did it by putting higher level concepts into the language.