I recently rediscovered in on github at https://github.com/dbetz/advsys

Code: http://t3x.org/s9fes/advgen.scm.html

Sample adventure: http://t3x.org/s9game/index.html

Code of the sample adventure: http://t3x.org/s9fes/adventure.adv.html

  (location livingroom  
    (property  
      description "This appears to be the livingroom.  There is a hallway to  
                   the north and a closet to the west."   
      short-description "You are in the livingroom."   
      north hallway  
      west closet  
      south front-door-1))

compared with something like MDL -

  <DEFINE EAST-HOUSE ()  
      <COND (<VERB? "LOOK">  
      <TELL   
  "You are behind the white house.  In one corner of the house there  
  is a small window which is " ,LONG-TELL1 <COND (<TRNN 
  <SFIND-OBJ "WINDO"> ,OPENBIT>  
              "open.")  
            ("slightly ajar.")>>)>>

It does not use such a witty approach though. It uses JSON configuration files and I still need to make actions and events mutually arbitrarily nestable in the configuration files, to allow arbitrarily complex plots.

The core is there and people could write their own configuration files to give it an individual spin. All that is needed is sufficient creativity.

To bi imbobo bik fut *wesh fong imbobo belang wit bap deting finyish sera fo welte.

Desh kaxa mali fo mesach xiya.

> vedi ere kaxa

Da kaxa im finyish sera.

> openg kaxa

To openg da kaxa unte vedi wa mesach mali.