A Portable Z-Machine Interpreter
Frotz is an interpreter for Infocom games and other Z-machine games. It
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
Plays all Z-code games including V6.
Old-style sound support through OSS driver.
Optional dumb interface.
Default use of the Quetzal save file format. Command line option to
use the old format.
Distributed under the GNU General Public License.
Packages available for all popular distributions of Linux and BSD.
Source code in the form of a Git repository is available at
Frotz's Github page.
Source code packages are available at
Frotz's Sourceforge project page and
The Interactive Fiction Archive
A port of Frotz to Microsoft Windows.
A new port of Frotz (2.43 based) to PalmOS.
A port of Frotz to KDE.
A port of Frotz to Windows CE.
A port of Frotz to Nintendo's Game Boy Advance.
An AIM chat bot that uses Dumb Frotz.
Wired seems to like it.
- The Interactive Fiction Archive
The canonical archive for information and specimens of interactive fiction
of all kinds.
- The Infocom Homepage
Lots of information about what was once Infocom (now owned by
Activision). Links to where to
get new z-machine games and the Old Ones by Infocom.
The Inform Homepage
The compiler used to create interactive fiction that Frotz can play.
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.
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
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.
A Z-code interpreter for the Palm Pilot and compatibles.
Appears to be based on a pre-2.40 version of Frotz.
A Z-code interpreter written entirely in
Perl. Includes some features not found
in any other interpreter.
Another multi-platform/multi-OS zcode interpreter. Uses Glk for I/O.
Andrew Plotkin's X11 port of ZIP v2.0.7 by Mark Howell. Handles Z-Code
versions 1 through 5 and 8.
Also by Andrew Plotkin, a port of ZIP for Macintosh with System 7 or 8.
Another ZIP derivative.
A Z-code interpreter as a Java applet.
An interpreter for Spectrum +3, Amstrad PCW8000/9000/10 and Amstrad PCW16,
written by John Elliott. Might be portable to other CP/M machines.
A company started by some former Atari programmers and now owns what's
left of Infocom.
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
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