Oct 23, 2019
One of the things that makes Colossal Cave Adventure such an fantastic game is that there are so many ways to play it. The game has been ported to just about any computer you can think of, and that development activity isn't limited to the past. There are quite a few recent web-based ports of the game engine. One my favorite web Adventures can be found here: https://github.com/mmastrac/adventure. This implementation is relatively new, as of posting it
looks like code was contributed as recently as 16 days ago. It reimplements the Adventure game engine and but not the original data file, so it's a pretty faithful port.
Another option is, asl awyas, emulation. If you want to go that route then the Internet Archive is a wonderful resource. Archive.org has an impressive and ever expanding catalog of vintage software. And even better, they have a lot of their software archive available to use in-browser vie emulation. You can play Microsoft's port of Adventure on the Internet Archive here: https://archive.org/details/msdos_Microsoft_Adventure_1981.
If you want something more niche, the Internet Archive actually has a good number of ports of Adventure that you can run in browser:
Classic Macintosh: https://archive.org/details/mac_Adventure_350_point_James
One final option, but this is only for the truly adventurous. A 1977 copy of the FORTRAN source code for Adventure is available. Both the game's engine and data file are direct from the keyboards of Crowther and Woods, making this the definitive way to experience Colossal Cave Adventure. However, you have to compile it first. And gfortran doesn't seem to like it, so there will probably be a lot of work involved with getting it to run. You can find the 1977 source code here: http://www.icynic.com/~don/jerz/
To learn more about Colossal Cave Adventure, you can listen to my episode on the topic: