Microsoft Open-Sources Classic Zork Trilogy Under MIT License for Preservation

Microsoft has announced the open-sourcing of the original Zork I, Zork II, and Zork III text adventure games, making their foundational code available under the MIT License. This initiative, a collaboration between Microsoft's Open Source Programs Office (OSPO), Team Xbox, and Activision, aims to preserve a significant piece of gaming history and facilitate its study by students, teachers, and developers. The announcement highlights the preservation of the innovative Z-Machine engine that powered these iconic games.

The Zork series, which originated in 1977, revolutionized interactive fiction by building immersive worlds through text alone. The Z-Machine, a custom-built virtual machine, was a key technical innovation, allowing Infocom to adapt the large mainframe game into three parts for early home computers and ensure cross-platform compatibility across systems like Apple IIs and IBM PCs. This design made Zork one of the first truly cross-platform games.

"Our goal is simple: to place historically important code in the hands of students, teachers, and developers so they can study it, learn from it, and, perhaps most importantly, play it," stated Microsoft in its official blog post. The open-source release includes the original source code, accompanying documentation, and build notes, with contributions officially submitted to historical repositories maintained by digital archivist Jason Scott of the Internet Archive. This move formalizes community archival work and secures the educational future of the Z-Machine architecture.

Microsoft acquired the rights to the Zork intellectual property through its 2023 acquisition of Activision, which had previously acquired Infocom in 1986. While the source code is now freely available for study and compilation using modern tools like ZILF, the release specifically excludes commercial packaging, marketing materials, and trademark rights, which remain with their respective owners. The games continue to be commercially available via "The Zork Anthology" on Good Old Games for those seeking a ready-to-play experience.