A Portable Z-Machine Interpreter

Frotz is an interpreter for Infocom games and other Z-machine games. It complies with standard 1.0 of Graham Nelson's specification. It was written by Stefan Jokisch in 1995-1997. It was ported to Unix by Galen Hazelwood. Currently the Unix port is being developed and maintained by David Griffith. The Unix port is also the canonical core version upon which all other ports are based.


  • Compiles and runs without changes on most common flavors of Unix, both open source and not. This includes MacOS X.
  • Portable to many other operating systems and hardware.
  • Plays all Z-code games including V6.
  • Old-style sound support through OSS driver.
  • Config files.
  • User-configurable error-checking.
  • Optional dumb interface.
  • Uses the Quetzal save file format.
  • Distributed under the GNU General Public License.
  • Packages available for all popular distributions of Linux and BSD.

    Get Frotz for Unix.

    Source code packages are available at Frotz's Sourceforge project page and The Interactive Fiction Archive

    The latest work on Frotz is available at Frotz's Github page.

    Current ports of Frotz to other machines

    Windows Frotz
    A port of Frotz to Microsoft Windows.
    iPhone Frotz
    iPhone Frotz source code
    A port of Frotz to Apple's iOS.
    GBA Frotz
    A port of Frotz to Nintendo's Game Boy Advance.
    An Infocom playing bot for IRC.
    CliFrotz Frotz for PalmOS machines.

    Other Links

    Interactive Fiction

    The Interactive Fiction Archive
    The canonical archive for information and specimens of interactive fiction of all kinds.
    The Interactive Fiction Community Forum
    A web-based forum for discussion of all aspects of Interactive Fiction.
    The Inform Homepage
    The compiler used to create interactive fiction that Frotz can play.
    Andrew Plotkin's website.
    Also known as Zarf, he is one of the guys who runs The Interactive Fiction Archive. He has also contributed quite a bit to the Interactive Fiction community in many other ways.
    Z-Machine Standards
    Read about a write-once run-many concept created before Java was a twinkle in Sun's eye.
    XYZZYnews is an electronic newsletter about interactive fiction. You'll also find plenty of links to other interactive fiction sites.
    Another 'zine about interactive fiction.
    Baf's Guide to the Interactive Fiction Archive
    Cross-referenced pages on IF platforms, authors, companies, games, genre, and so on. Great for finding a game to suit your mood.
    IF Comp
    Homepage of the Annual Interactive Fiction Competition.
    IF Legends
    A place where lots of different webpages are hosted which have to do with Interactive Fiction.


    This program started as a remake of Mark Howell's Zip, but has grown into a completely new interpreter with ports for lots of platforms.

    Thanks goes to Stefan Jokisch for writing Frotz and Galen Hazelwood for doing the initial work of porting it to Unix. Thanks also to Jim Dunleavy for his optimization to the core Frotz code. Other people to thank include those who uploaded patches to Unix Frotz to the IF-Archive and getting me interested in the inner-workings of interpreters like Frotz, people who posted to Usenet feedback on what I was doing, testers, those who donated the use of machines for porting, sent me patches, etc. These include, but are not limited to:

    Torbjorn Anderson, Timo Korvola, Martin Frost, Mihail Milushev, David Picton, Chris Sullivan, Leonard Richardson, Stephen Kitt, Paul E Coad, Paul Janzen, Brad Town, Jason C Penney, Denis Hirschfeldt, Jacob Nevins, Matteo De Luigi, Steven Frank, Thomas Troeger, and others that I've forgotten.

    Michael Edmonson (author of Rezrov) and Evin Robertson (author of Nitfol) deserve recognition for the ideas that I've borrowed from their programs. Al Petrofsky (creator of dumbfrotz) donated much code to allow Unix Frotz to semi-support V6 games.

    This page was last updated on December 20, 2013