Colossal Cave Adventure (also known as ADVENT, Colossal Cave, or Adventure) gave its name to the computer adventure game genre. It was originally designed by Will Crowther, a programmer and caving enthusiast who based the layout on part of the Mammoth Cave system in Kentucky. The Colossal Cave subnetwork has many entrances, one of which is known as Bedquilt. Crowther reproduced portions of the real cave so faithfully that cavers who have played the game can easily navigate through familiar sections in the Bedquilt region on their first visit.
Will Crowther was a programmer at Bolt, Beranek & Newman, which developed the ARPANET (a forerunner of the Internet). Crowther was an experienced caver, who applied his experience in Mammoth Cave (in Kentucky) to create a game that he could enjoy with his young daughters.
Crowther had explored the Mammoth Cave in the early 1970s, and created a vector map based on surveys of parts of the real cave, but the text game is a completely separate entity, created during the 1975-76 academic year and featuring fantasy elements such as an axe-throwing dwarf and a magic bridge.
The version that is best known today was the result of a collaboration with Don Woods, a graduate student who discovered the game on a computer at Stanford University and made significant expansions and improvements, with Crowther's blessing. A big fan of Tolkien, he introduced additional fantasy elements, such as elves and a troll.
When Roberta Williams and her husband Ken discovered the game, and were subsequently unable to find anything similar, they were inspired to create their own software house, founding On-Line Software (later Sierra Online, and then Sierra Entertainment), which created the first graphical adventure game (Mystery House), and quickly became a dominant player in the entertainment software market for the next two decades, creating successful adventures such as King's Quest, Space Quest, and Leisure Suit Larry.
Microsoft released a version of Adventure in 1981 with its initial version of MS-DOS 1.0 for the IBM PC (on a single sided disk, requiring 32kB of RAM). This was released on a 5.25 inch disk and booted directly from the disk. It could not be opened from DOS. This version contained 130 rooms, 15 treasures, 40 useful objects and 12 problems to be solved. The progress of two games could be saved on a diskette.