When Zork arrived, it didn’t just ask players to win; it asked them to imagine. There were no graphics, no joystick, and no soundtrack, only words on a screen and the player’s curiosity. Yet those words built worlds more vivid than most games of their time. What made that possible wasn’t just clever writing, it was clever engineering.

Beneath that world of words was something quietly revolutionary: the Z-Machine, a custom-built engine. Z-Machine is a specification of a virtual machine, and now there are many Z-Machine interpreters that we used today that are software implementations of that VM. …