ADVENTURE  was  originally  developed  by  William Crowther, then at 
BBN in Cambridge, Massachusetts, and later substantially rewritten and 
expanded by Don Woods  at  Stanford University.   According to legend, 
Crowther's original version was modelled on an a real cavern, called 
Colossal Cave, which is a part  of  Kentucky's  Mammoth  Caverns. That 
version  of  the  game  included the main maze and a portion of the 
third-level (Complex Junction - Bedquilt - Swiss Cheese rooms, etc.), but 
not much more.

Don Woods and some others at Stanford later rewrote portions of the 
original  program, and  greatly expanded the cave.  That version of the 
game is recognizable by the maximum score of 350 points.  This (350-
point) version seems to  have  been  adapted  to  nearly every  known 
type of computer found outside the Iron Curtain, or inside, for all I 
know. Don was kind enough to transmit the source program to the present 
author in mid-1977.

The latest additions were done throughout 1978-80 by David Long at the  
University  of Chicago, Graduate School of Business.  Additions include 
the seaside entrance and all of the cave on the "far side" of Lost River 
(Rainbow Rm - Crystal Palace -  Blue  Grotto  -Rotunda - Joshua's wall, 
the Gothic Cathedral, etc.).  The surface has also been greatly increased 
to include a much more varied landscape containing swamp, marsh, seashore  
and meadowland  areas.    Most  recent  additions  include  the  great  
Castle of Aldor, the Elephants' Burial Ground, Sham Rock, the Lost Silver 
Mine, the  helicopter,  the  Secret Garden, Bigrat and more.  The current 
cave is nearly triple the size of the Woods model, and moreover the 
puzzles and treasures are somewhat more "dense", (and more  difficult!) 
in  the  current  version.    During the expansion process, the code was 
almost entirely rewritten to permit more generalized handling of objects 
and to interpret a more complex natural English syntax.

Except  for  a  few  trivial  subroutines  (to get user-ID's for 
logging purposes, for example), ADVENTURE is written entirely in FORTRAN.  
This not because the  authors  love FORTRAN,  but  because it is almost 
infinitely portable.  There were indeed moments when it took great 
strength to withstand the temptation to whip out some  character  
handling routine  in Assembler, instead of the furshlugginer compiler.  
This was the problem with the first versions of DUNGEON (a.k.a. ZORK), 
developed  at  M.I.T.,  which,  though  now widely  available on personal 
computers, was for some time totally non-portable since it was originally 
coded in an obscure variant of LISP.

As a side note, in response to a frequently asked question, let me  add  
that  Dungeon (Zork)  and  Adventure-6  were  developed almost completely 
independently.  The advanced parser, the object containment  facility,  
and  virtually  all  the  game  puzzles  were designed  and  implemented  
prior to our receiving any version of Dungeon.  With all due modesty 
(none), I will point out that Adventure's containment facility is  at  
least  as powerful  as Dungeon's, if not more so, since Adventure's 
facility permits searching for contained objects in open containers down 
to any desired level of containment.  Further, the  parser permits a few 
constructs not currently permitted in Dungeon (at least in the version we 
have at U.C.), such as permitting any number of objects (up  to  some  
limits imposed  by  compiled  array  sizes)  to  be  specified  following 
transitive verbs. In addition, Adventure's parser can handle multiple 
verb constructs such as "GET AND  THROW AXE"  properly.    Finally,  
Adventure's parser is slightly better about doing the right things with 
the various applications of the  group  words  "ALL"  and  "TREASURES".    
A planned  enhancement  for  Release  7  will  permit  such constructs as 
"PUSH ALL OF THE BUTTONS" or "TAKE BOTH SACKS", etc.