Editing Colossal Cave Adventure (section)

==Development==
===Crowther's original version===
[[File:Will Crowther Fall 2012.jpg|right|thumb|William Crowther in 2012|alt=William Crowther]]
[[File:ASR-33 at CHM.agr.jpg|right|thumb|[[Teleprinter]] [[computer terminal]]|alt=ASR-33 Teleprinter]]
''Colossal Cave Adventure'' was originally created by [[William Crowther (programmer)|William Crowther]] in 1975 and 1976. Crowther and his ex-wife [[Patricia Crowther (caver)|Patricia]] were both programmers and [[caving|cavers]] and had extensively explored [[Mammoth Cave National Park|Mammoth Cave]] in [[Kentucky]], the longest cave system in the world, in the early 1970s as part of the [[Cave Research Foundation]]. In 1972, Patricia led the expedition that found a connection between Mammoth Cave and the larger Flint Ridge Cave System. In addition to caving, the pair produced [[vector (mathematics and physics)|vector]] map surveys of the cave: they transcribed the survey data of the cave from "muddy little books" into a [[teleprinter]] terminal in their house, which could send and print messages from programs running on the central computer and was connected to a [[PDP-1]] [[mainframe computer]] at [[Raytheon BBN|Bolt, Beranek and Newman]] (BBN) where William Crowther worked. This data was then fed into a program developed by the pair that generated [[plot (graphics)|plotting]] commands onto [[punched tape]], which were then fed into a [[Honeywell 316]] [[minicomputer]] attached to a [[Calcomp plotter|Calcomp drum plotter]] at BBN to print paper maps. These maps were some of the earliest computer-drawn maps of caves.<ref name="BroadBand"/>

In 1975, after he and Patricia divorced, William Crowther stopped caving with the Cave Research Foundation. Driven by what he later described as an increase in spare time combined with missing his two daughters, he began working on a text-based game in [[Fortran]] on BBN's [[PDP-10]] mainframe, interfacing through a teletype printer, that they could play.<ref name="DH2007"/><ref name="Lessard2013"/><ref name="Peterson187188"/> He combined his memories and maps of the Mammoth Cave system, particularly a 1975 map of the Bedquilt area of the caves, including [[Colossal Cavern]], with elements of the ''[[Dungeons & Dragons]]'' campaigns that he played with friends to design a game around exploring a cave for treasure.<ref name="DH2007"/><ref name="Peterson187188"/> Crowther wanted the game to be accessible and not intimidating to non-technical players such as his children, and so developed a [[natural language processing|natural language input]] system to control the game so that it would be "a thing that gave you the illusion anyway that you'd typed in English commands and it did what you said".<ref name="Montfort9192"/> Crowther later commented that this approach allowed the game to appeal to both non-programmers and programmers alike, as in the latter case, it gave programmers a challenge of how to make "an obstinate system" perform in a manner they wanted it to.<ref name="Montfort9192"/> This approach was also developed to allow the game to be played on a teletype printer, rather than rely on user interface elements used in programs designed for monitors.<ref name="Lessard2013"/>

The initial version of the game was about 700 lines of code, plus another 700 lines of data such as descriptions for 66 rooms, navigational messages, 193 vocabulary words, and miscellaneous messages.<ref name="DH2007"/><ref name="OriginalSourceCode"/> Once the game was complete, in early 1976, Crowther showed it off to his co-workers at BBN for feedback, and then considered his work on the game finished, leaving the compiled game on the mainframe before taking a month off for vacation. According to one of Crowther's then-coworkers in 2007, "once it was working, Will wasn't very interested in perfecting or expanding it." Crowther's work at BBN was in developing [[ARPANET]], one of the first networks of computers and a precursor to the Internet, and the PDP-10 mainframe was part of that network. During his vacation, others found the game and it was distributed widely across the network to computers at other companies and universities, which surprised Crowther on his return. The game did not have an explicit title in it, simply stating "WELCOME TO ADVENTURE!!" as a part of the opening message and having a file name of ADVENT; it was referred to as both ''Adventure'' and ''Colossal Cave Adventure'', with the latter becoming the more common name over time.<ref name="DH2007"/> Most [[computer terminal]]s at the time did not have [[computer monitor|monitors]], and players would instead play the game over teleprinters connected to the mainframe.<ref name="teleprinter"/>

===Woods's modifications===
[[File:Don woods cropped.png|right|thumb|Don Woods in 2010|alt=Don Woods]]
One person who discovered the game was [[Don Woods (programmer)|Don Woods]], a graduate student at [[Stanford University]]. Woods found the game on a PDP-10 at the Stanford Medical School and wanted to expand upon the game. He contacted Crowther to gain access to the source code by emailing "crowther" at every domain that existed on the ARPANET.<ref name="DH2007"/><ref name="peterson188190"/> Woods built upon Crowther's code, introducing more [[high fantasy]]-related elements such as a dragon.<ref name="TCW383385"/><ref name="Barton3639"/> He changed the puzzles, adding new elements and complexities, and added new puzzles and features such as a pirate that roams the map and steals treasure from the player or objects that could exist in multiple states.<ref name="DH2007"/> He also introduced a scoring system within the game and added ten more treasures to collect in addition to the five in Crowther's original version.<ref name="peterson188190"/>

According to cavers who have played the game, much of Crowther's original version matches the Bedquilt section of Mammoth Cave with some passages removed for gameplay purposes, though Woods's additions do not as he had never been there.<ref name="DH2007"/><ref name="BroadBand"/> According to William Mann, a caving compatriot of Crowther who played both versions when they were developed, Crowther was focused on creating the cave system as a setting for a game, while Woods was interested in making a game and not in replicating the feeling of caving.<ref name="DH2007"/>

Woods's version, released in 1977, expanded Crowther's game to approximately 3,000 lines of code and 1,800 lines of data, growing to 140 map locations, 293 vocabulary words, and 53 objects.<ref name="WoodsSourceCode"/> Woods also added access controls to the game, allowing mainframe administrators to restrict the game from running during business hours.<ref name="DH2007"/> Woods began working on the game in March 1977; by May his version was complete enough to release, and was soon attracting attention around the United States.<ref name="DH2007"/> Woods continued releasing updated editions in Fortran until 1995.<ref name="peterson188190"/> Crowther later said that Woods's bringing fantasy elements earlier into the gameplay was an improvement to his version, though Crowther's daughters also recall him telling them when they were frustrated at puzzles in the game that it was one of Woods's additions, not his.<ref name="DH2007"/>

Crowther did not distribute the source code to his version to anyone else, and it was later believed to be lost until it was rediscovered on an archive of Woods's student account at the [[Stanford Artificial Intelligence Laboratory]] in 2005.<ref name="DH2007"/> Woods, however, distributed the code to his version alongside the compiled executable. Woods's 1977 version became the more recognizable and widespread version of ''Colossal Cave Adventure'', in part due to its wider code availability, as it led to several other variants of the game being produced.<ref name="Lessard2013"/><ref name="Montfort9192"/>

===Later versions===
[[File:You are standing.jpg|thumb|Unix version of the game on an [[Osborne 1]] computer circa 1982|alt=Monitor showing Colossal Cave Adventure]]
Both Crowther's and Woods's version were designed to run on the PDP-10 and used features unique to [[Fortran#FORTRAN_IV|DECSYSTEMS-10 Fortran IV]] on that architecture, meaning that the program could not be easily moved to other systems, even those that could run Fortran programs. One of the first efforts to [[porting|port]] the code to other languages or systems was by [[RAND Corporation]] researcher [[James Gillogly]] in 1977. Gillogly, with agreement from Crowther and Woods, spent several weeks porting the code to the [[C (programming language)|C programming language]] to run on the more generic [[Unix]] architecture.<ref name="Electracity97"/> It can still be found as part of the [[Berkeley Software Distribution|BSD]] Operating Systems distributions, or as part of the "bsdgames" package under most [[Linux]] distributions, under the command name "adventure".<ref name="BSDadventure"/> Bob Supnik of [[Digital Equipment Corporation]] also ported the game in Fortran to the [[PDP-11]] minicomputer in mid-1977, spreading it to other minicomputer systems.<ref name="GetLampSupnik"/> Afterwards, numerous other ports were made of the game to different languages and systems, sometimes identified by the number of points available in the game.<ref name="RaymondHistory"/> There were enough ports and variants and alternate takes of the game by 1982 that an article in ''[[Your Computer (British magazine)|Your Computer]]'' described the entire set of games wherein the player enters short commands to move between set locations as "''Adventure'' games", and provided code for the [[ZX81]] computer for an "Adventure-writing kit" program that could be used to generate a game with that gameplay.<ref name="ZX81writingkit"/> In 2017, [[Eric S. Raymond]] created a port for modern computers of Woods's 1995 version of the game as ''Open Adventure'' and released the source code under an [[open-source license]] with permission from Crowther and Woods.<ref name="RaymondHistory"/><ref name="OpenAdventure"/>

Commercial versions of the game were also released. [[Microsoft]] published a version titled ''[[Microsoft Adventure]]'' in 1979 for the [[Apple II Plus]] and [[TRS-80]] computers, and again in 1981 for [[MS-DOS]] as a launch title for [[IBM Personal Computer|IBM PC]]s, one of the few software programs and the only game at launch.<ref name="BYTE79"/><ref name="BYTEIBM"/> [[The Software Toolworks]] released ''The Original Adventure'' for IBM PCs in 1981; endorsed by Crowther and Woods in exchange for a nominal payment, it was the only version for which they received any money.<ref name="bilofsky"/> [[Level 9 Computing]] released multiple versions of the game for different computer platforms under the name ''[[Colossal Adventure]]'', beginning with a version in 1982 for the [[Nascom (computer kit)|Nascom]] that includes an entire extra section where the player saves elves from flooding caves, as well as later versions that include pictures of the areas.<ref name="ColossalAdventure"/>

A 3D remake of the game, under the title ''Colossal Cave'', was released by Cygnus Entertainment as its first title in on January 19, 2023, for [[Microsoft Windows|Windows]], [[macOS]], [[Linux]], [[Nintendo Switch]], [[PlayStation 5]], [[Xbox Series X]], and [[Meta Quest 2]].<ref name="3DAdventure"/> Designed by [[Ken Williams (game developer)|Ken]] and [[Roberta Williams]], co-founders of [[Sierra Entertainment]], the game was started as a hobby project by the pair during the [[COVID-19]] pandemic, before being expanded into a full commercial product by a team of thirty.<ref name="PSRemake"/> It was intended by lead designer Roberta to be a recreation of how playing the game felt like to her in 1979.<ref name="ViceRemake"/>