The source code of every Infocom text adventure game has been uploaded to code-sharing repository GitHub, allowing savvy programmers to examine and build upon some of the most beloved works of digital storytelling to date.

There are numerous repositories under the name historicalsource, each for a different game. Titles include, but are not limited to, The Hitchhiker's Guide to the Galaxy, Planetfall, Shogun, and several Zork games—plus some more unusual inclusions like an incomplete version of Hitchhiker's sequel The Restaurant at the End of the Universe, Infocom samplers, and an unreleased adaptation of James Cameron's The Abyss.

The code was uploaded by Jason Scott, an archivist who is the proprietor of textfiles.com . His website describes itself as "a glimpse into the history of writers and artists bound by the 128 characters that the American Standard Code for Information Interchange (ASCII) allowed them"—in particular those of the 1980s. He announced the GitHub uploads on Twitter earlier this week.

The games were written in the LISP-esque "Zork Implementation Language," or ZIL, which you could be forgiven for not being intimately familiar with already. Fortunately, Scott also tweeted a link to a helpful manual for the language on archive.org.

Dive in and you'll find that things are very different now than they were then. At the time Infocom was active, personal computers did not have a widely shared architecture, so the path ZIL's architects took was to allow game creators to write instructions for a virtual machine called the Z-machine, which was then brought to the various platforms of the day. There are interpreters available today for Windows, macOS, Linux, iOS, and Android, among other platforms.

The interactive fiction community is still quite lively, and people are still making games using ZIL and the Z-machine today. But they've been joined by creators using new tools for spinning interactive, text-focused games like Twine and Ink, some of which are used as middleware in modern graphical game productions big and small.

Gamasutra, a site which covers news for the game development industry, also noted that Activision still owns the rights to Infocom games and could request a takedown if it wanted. For now, though, historians, narrative designers, programmers, and gaming enthusiasts alike can benefit from Scott's effort.