ABOUT
colossalcave.cc - A faithful web port
Colossal Cave Adventure - known simply as Adventure - was written by Will Crowther in 1975 and substantially expanded by Don Woods in 1977. It ran on a PDP-10 mainframe at Stanford University's Stanford Artificial Intelligence Laboratory, accessible to users via TOPS-10 timesharing.
It is, without serious argument, the most important computer game ever written. It invented the text adventure genre, established the conventions of interactive fiction, and planted the seed of what would become the modern video game industry. Zork, Infocom, and an entire lineage of games trace their ancestry directly to this program.
Crowther was a caver and a programmer at BBN Technologies - the company that built ARPANET. The cave system in the game is based on Mammoth Cave in Kentucky, which Crowther had mapped. He wrote the game partly for his daughters after a divorce, wanting to share the experience of caving with them through the medium he knew best.
This implementation is a strict port of the original PDP-10 FORTRAN source code - specifically the adv350-pdp10 release, the definitive version of the 350-point game. Every room description, every message, every puzzle, every scoring threshold, every quirk of the parser is taken directly from the original source. Nothing has been modernised, softened, or reinterpreted.
The game runs on a PHP backend that faithfully emulates the original FORTRAN logic, including the wizard authentication system, the cave hours gate, the dwarf AI, the lamp depletion curve, and the full scoring and classification system. The frontend renders in a fixed 80-column terminal display using the VT323 font, matching the character dimensions of the VT100 terminals on which the game was originally played.
The original program output all text in uppercase - a consequence of the TOPS-10 terminal driver, not the FORTRAN source itself. This port replicates that behaviour.
The cave operates on Stanford/Pacific time, matching the original PDP-10 behaviour. During prime time hours it is closed to general visitors, exactly as it was in 1977.
The authoritative PDP-10 FORTRAN source (advent.for, adv350-pdp10) is preserved and publicly available. It remains one of the most studied programs in computing history.
Will Crowther - original game, 1975
Don Woods - expansion and refinement, 1977
Nick Webster - this web port, 2026