Application: Inform 7
Description: Inform is a design system for interactive fiction based on natural language. It is a radical reinvention of the way interactive fiction is designed, guided by contemporary work in semantics and by the practical experience of some of the world's best-known writers of IF.
[Link removed, Inform 7 is not open source and may not be distributed without permission, and may not be distributed on SourceForge at all - mod Chris]
Development Test 1 (2011-05-03): Initial release