Back in 2019, Adafruit wrote about the source code for Zork, an early Infocom game from the 1980s, had been posted on GitHub. Ars Technica is reporting now that the “game engine”, the code that interpreted the Infocom Zork Implementation Language that defined a game, was quietly posted to GitHub by Andrew Plotkin.

Most of Infocom’s games were written in “Zork Implementation Language,” which was native to no particular platform or processor, but ready to be interpreted on all kinds of systems by versions of its Z-Machine. The Z-Machine could be considered the first real game development engine, so long as nobody fact-checks that statement too hard. Lots of work has been done in open source realms to create modern, and improved, versions of these interpreters for pretty much every device imaginable.

Plotkin also notes that he dropped the files on GitHub without announcing it or making “a big fuss.” That’s because he’s actively negotiating with Infocom’s modern rights-holders to open-source the legendary firm’s work. For a while, that meant Activision, which acquired Infocom in 1986. Now, it means Microsoft, which acquired Activision in October.

Read more on Ars Technica.