This is a JavaScript interactive fiction engine that is loosely based on my understanding of Inform 6 and Inform 7. The engine is meant to be very extensible, using poor-man's generic function for all basic functionality. The world model is like Inform 7's, where an object is merely its properties and relations to other objects (but we don't try to derive a minimal first-order model given the description of the world -- we cheat and use default values for properties!)
The library is a port of textadv and it is a work in progress.