Bocfel Z-machine interpreter


Bocfel is an interpreter for the Z-machine. It fully supports versions 1-5, 7, and 8, and contains partial support for version 6. For detailed information on Bocfel’s operation, please consult the man page.

Bocfel can be downloaded from the downloads page.

The Z-machine

The Z-machine was designed to run text adventure games, also known as interactive fiction. Originally the only Z-machine games were created by Infocom, the company that created the Z-machine. These include such games as Zork, The Hitchhiker’s Guide to the Galaxy, and Planetfall. Fans of the genre figured out the format of the Z-machine, allowing non-Infocom interpreters, such as this one, to be built.

After that, a compiler for the Z-machine, called Inform, was released. Initially a language meant for programmers, the latest iteration of Inform is intended to allow non-programmers to easily write interactive fiction. Thanks to Inform, hundreds of Z-machine story files have been written by enthusiasts, a number of which are of extremely high quality.

Although interactive fiction is today a rather niche genre, it has a loyal following of both players and authors, and can be explored through the following resources, among others:


Some of Bocfel’s features

  • Almost no platform-specific functions are used—and those that are used are optional—so almost any system with a recent C compiler should be able to build and run Bocfel.
  • Makes use of Glk for input/ouput, with complete support for Gargoyle; a non-Glk “dumb” interface is also available.
  • Support (assuming a font with Unicode box-drawing characters) for the character graphics font used by Beyond Zork.
  • Unicode support: see, for example, Chinese characters used by Mingsheng or the Russian translation of Spider and Web.
  • Multiple undo in almost all games, including those which do not natively support it.
  • Full control over command recording, transcripting, and command-record playback.
  • Rudimentary “cheating” support, designed to disable hunger and thirst daemons.

Only the source code to Bocfel is provided here. If you are interested in a runnable binary, Ben Cressey has integrated Bocfel into the latest version of Gargoyle as the default Z-machine interpreter.


Please report bugs to Gargoyle’s issue tracker.