The Z-machine is a virtual machine architecture designed by Infocom for their interactive fiction games. It allows a single game program (called a story file) to run on many different computer systems with a Z-machine interpreter. This innovative approach ensured that Infocom's complex narratives and game mechanics could reach a wide audience across diverse hardware. The Z-machine's design focused on efficiency and portability, making it a cornerstone of early interactive fiction development and a testament to clever software engineering.