Frotz - an interactive fiction plugin for Koreader

[kbarni]

Frotz - Interactive fiction games in Koreader
Version 2.2 - Updated on sept 2 2026

Frotz is an interactive fiction interpreter plugin to play IF games right from Koreader!

IF games were in vogue at the beginning of the PC era, at the end of the '70s and beginning of the '80s, with games like Zork, Planetfall, A Minf Forever Voyaging. The genre was well adapted to early computers, but it went out of mainstream with the introduction of stronger computers and multimedia capabilities.

However a small and devoted group continued to develop IF games, with more advanced parsers, pushing the limits of the genre that no other video games can achieve (e.g. manipulating words instead of objects in Counterfeit Monkey).

IF is still a game genre that is particularly well adapted for e-readers. It is text-heavy - so easy to read on the e-ink display, and doesn't need frequent redraws. In addition, reading enthusiasts should appreciate the quality interactive fiction games. Did I mention that these games are completely free?

Installation and running

Download the plugin from github. Unzip it to the koreader/plugins folder.

Start from the Tools menu -> Interactive fiction.

Features

• Accepts Z-machine (.zX, .zblorb, .zlb) and Glulx (.gblorb) games - most of the IF games are in these format
• Text styling (bold/italic)
• Basic graphics support
• Improved saving and loading (per game and slots), including autosave
• Game history management with auto restore
• Hide the on-screen keyboard when using external keyboard for full screen display
• Dictionary lookup for selected words
• Adjustable font size
• Support for most e-ink devices: Kindle, Kobo, Remarkable, Pocketbook and desktop Linux (ARM-SF, ARM-HF, ARM-64 and X86-64). Android is not supported.

Further resources

There are several dedicated webpages for IF games: IFDB and IFWiki are just two of them. They have all the games, with recommendation lists, reviews, contest results and other articles.

Gargoyle is a more polished IF interpreter which supports graphics, advanced text formatting and more formats. It is available for Kindle.

Note: this plugin kept the Frotz name since the original release, but currently it uses the Git and Bocfel interpreters.

Full source code here.

[kbarni]

I just updated Frotz plugin to version 2.0
The interpreter was switched to Bocfel and Git, so it can play Glulx (gblorb) in addition to Z-machine (z1-z8, zblorb) games, and it also supports text styles and header bar.

New features since version 1:

• Glulx and Z-machine game support
• Text styling (bold/italic)
• New font with typewriter style
• Status bar header
• Dictionary lookup for selected words

Graphics and color support is still missing, but otherwise everything works.

Same link for download.

[kbarni]

Frotz 2.2 - new update adds graphics support.

Images will appear as link texts like [Illustration 1] in the transcription. Click the link to display the image.

It only supports story related images, not decorative images (like text separators or border decorations).
You can test it with Everybody dies (several images) or Violet or Lost pig (cover image)

Get the latest release here.

[kbarni]

Game recommendations

Interactive fiction (IF) games had a great success in the '80s, at the beginning of the PC era. The computers in that time had basic graphical capabilities, but could process text fairly well. They fell out of the mainstream first with the appearance of point and click adventures, then even more complex games with the 3D graphics, CD-ROMs and much larger development teams.

IF never disappeared, a sub-culture of enthusiasts continued developing the parsers and the games, pushing the limits of the genre. How would an alien, that feels energies and emotions instead of seeing survive our planet? Or how can you escape the island of linguistics, where you manipulate words instead of objects?

That said, these games require patience (it's a kind of game where you just take your time), and some learning curve. That said, they are an interesting reading experience and very well adapted for the e-ink displays.

As you don't have to type a lot, they are usable with the on-screen keyboard, but an external keyboard can be better.

Some of the games I started with are:
- Dreamhold (classic fantasy setting, easy for beginners)
- Bronze (Another beginner friendly game, a Beauty and the Beast remix)
- Counterfeit Monkey (highly recommended, visit the island of linguistics)
- Coloratura (see the earth from the point of view of an alien)
- Violet (I could relate to it, writing my PhD)
- 9:05 (short and fun story)

[shuvashish76]

Just watched https://www.youtube.com/watch?v=KWOncGiMtk0

Originally Posted by kbarni

Game recommendations
That said, these games require patience (it's a kind of game where you just take your time), and some learning curve. That said, they are an interesting reading experience and very well adapted for the e-ink displays.

With this LLM era attention span getting shorter, interesting type of games if you're above certain age

[jbaumann]

I just installed the newest version of the plugin (2.2) on a current version of KOReader (2026.07.1). The integration into KOReader works (the menu is shown, when I try to start a game the "Recent Games" entry is updated), but then a message is shown that the plugin failed to start the VM "binary missing or not executable" (armhf/bocfel). The executable's path seems to be correct and it has the exec flag. If I try to start the executable (bocfel) directly from the command line, nothing happens, but no error either.

What can I do to fix this?

And thank you for your work, Joachim
PS: The same happens with v2.1…

[Jellby]

Originally Posted by shuvashish76

With this LLM era attention span getting shorter, interesting type of games if you're above certain age

See also https://www.mobileread.com/forums/sh...d.php?t=375080