Open Source IF

Open Source IF is interactive fiction that is released together with its source code. This allows other authors to study the source code and see how things were done. Unlike free software, open source software does not necessarily allow you to modify and redistribute the work. (It should be noted that this terminological difference is not universally accepted, as some people and organisations use open source software as a synonym of free software.) Free software Interactive Fiction will not be listed below, since it already has its own page.

Interactive Fiction released as Open Source Software

Creative Commons Licenses

Although the Creative Commons licenses have not been specifically designed for software, they have nevertheless been used for several Interactive Fiction programs.

Attribution-Noncommercial-Share Alike 3.0 Unported

This license allows you to redistribute and adapt the work, as long as you attribute the work in the manner specified by the author or licensor, do not use it for commercial purposes, and release it under this same license.

NonCommercial Sampling Plus 1.0

This license allows you to copy and adapt the work, but only on the conditions that (1) it be used non-commercially; (2) the derivative work constitute a good-faith partial or recombined usage employing "sampling," "collage," "mash-up," or other comparable artistic technique, whether now known or hereafter devised, that is highly transformative of the original; (3) the original work is either only partially used, or forms an insubstantial portion of the derivative work, or the derivative work must be substantially transformed. Please refer to the license for further details.

• Child's Play by Stephen Granade, Inform 7.

Home-brew Licenses

These programs are released under licenses that the author's have written themselves. As such, details may vary and a careful reading of the license text is necessary.

Licenses that do not allow derivative works

For these works, the source code is provided for studying it only: you are not allowed to redistribute any modified versions of the game.

• A Crimson Spring by Robb Sherwin, Hugo.
• Augmented Fourth by Brian Uri, Inform 6 (not entirely clear about the issue of derivative works).
• Chicks Dig Jerks by Robb Sherwin, Inform 6.
• Christminster by Gareth Rees, Inform 6.
• Deadline by Marc Blank, ported by Volker Lanz to Inform 6 ("Please do not distribute modified versions of these files.").
• Ditch Day Drifter by Michael J. Roberts, ported by Neil Cerutti to Inform 6 ("You may not modify this archive in any way.").
• Hunter, in Darkness by Andrew Plotkin, Inform 6. ("This source code is provided for personal, educational use only. The story and text of _Hunter, in Darkness_ belong to me; you may not use them or create derivative works which contain them. However, you have permission to use the programming techniques of this game in your own works, and you may use the source code excluding game text.")
• Once: a fable for the lost by Robin Andrews, Inform 6. ("All rights reserved.")
• Shade by Andrew Plotkin, Inform 6. ("This source code is provided for personal, educational use only. The story and text of Shade belong to me; you may not use them or create derivative works which contain them. However, you have permission to use the programming techniques of this game in your own works, and you may use the source code excluding game text.")

Licenses that do allow derivative works

These works do allow you to redistribute modified versions of the game, but place one or more restrictions on the process of changing or distributing that are incompatible with free software.

• The Awakening by Dennis Matheson, Inform 6 (almost free software; you are not allowed to charge for distribution).
• Beyond Zork Example by Allen Garvin, Inform 6 (commercial uses not allowed; based on copyrighted Infocom material, so of questionable legality).
• Chicken and Egg by Adam Thornton, Inform 6. ("Feel free to copy this, modify it, whatever, but don't sell it and don't pretend you wrote it from scratch."--public statement on rec.arts.int-fiction.)
• In the End II by Adam Thornton, Inform 6. ("You are hereby encouraged to modify it, to add better syntax for some of the commands, and to add new and exciting ways to not-quite die. Just make the changes that you make freely available with source, and keep all the original credits in the game as well as any you may add.")
• Risorgimento Represso by Michael Coyne, Inform 6 (attribution required; not for commercial purposes).
• Sins Against Mimesis by Adam Thornton, Inform 6. ("Feel free to copy this, modify it, whatever, but don't sell it and don't pretend you wrote it from scratch."--public statement on rec.arts.int-fiction.)
• Stiffy Makane: The Undiscovered Country by Adam Thornton, Inform 6. ("Feel free to copy this, modify it, whatever, but don't sell it and don't pretend you wrote it from scratch.")

No Licensing Information

There are quite a lot of source code files on the IF Archive that do not come with any licensing information. As such, it is better not to assume that you can use this source code for your own works, unless you get explicit permission from the authors. For ports of a game to another authoring system, this means you must ensure that both the original author and the porter give you permission to use the code.

• Adventure by Will Crowther and Don Woods, ported by Donald Ekman, David M. Baggett and Graham Nelson to Inform 6.
• Adventureland by Scott Adams, ported by Graham Nelson to Inform 6.
• Back to WakeUp by Daniel Roperto, Inform 7.
• Balances by Graham Nelson, Inform 6.
• Beneath: a Transformation by Graham Lowther, Inform 6.
• The Big Mama by Brendan Barnwell, Inform 6.
• Cattus Atrox by David Cornelson, Inform 6.
• Cave by William Stott, Inform 6.
• Caverns of Chaos by Paul Martinez and Alison Castro, ported by lemonhead to Inform 6.
• C.I.A. Adventure by Hugh Lampert, ported by J. Kevin Thomas to Inform 6.
• Detective by Matt Barringer, ported by Stuart Moore to Inform 6.
  • Mystery Science Theater 3000 Presents "Detective", by C.E. Forman based on Detective by Matt Barringer, Inform 6.
  • An update of the previous entry by Stuart Moore, Inform 6.
• The Dragon and the Troll by Johan Berntsson, translated and ported by Fredrik Ramsberg to Inform 6.
• A Fable by Stan Heller, ported by Stuart Moore to Inform 6.
  • MiSTed parody version of A Fable by Stan Heller, parody by Graeme Cree, ported by Stuart Moore to Inform 6.
• HLA Adventureby Paul Allen Panks, ported by Roger Pepitone to Inform 6.
• Identity by Dave Bernazzani, Inform 6.
• It's a Dog's Life by Mr. WiggleButt, Inform 6.
• Killing the Doctor by Victor Verbitsky, Inform 6.
• Medusa by Jim Fisher, Inform 6.
• No Room by Ben Heaton, Inform 6.
• Odieus's Quest for the Magic Flingshot by Anonymous, converted to AGT and adapted by David Malmberg, ported by Teo Kwang Liak to Inform 5.4.
• Omniquest by Chris Barden and Chris Ethridge, adapted by Chris Barden to Inform 6.
• Rachel has a Bad Day by Sly Old Dog, ported by Roger Pepitone to Inform 6.
• Sting of the Wasp by Jason Devlin, Inform 6.
• Vespers by Jason Devlin, Inform 6.

IF Abuses released as Open Source Software

Some programs written in IF authoring systems are nevertheless not interactive fiction, but (say) implementations of chess or Tetris. Those are generally called abuses, and are listed here separately.

Home-brew Licenses

Licenses that do not allow derivative works

• Encyclopedia Frobozzica by Nino Ruffini, ported by Digby McWiggle to Inform 6. (Infocom Reference work. "Encyclopedia Frobozzica is copyright 1993, 1999 Activision, Inc. Used with permission." This permission presumably does not transfer to derivative works.)

Licenses that do allow derivative works

• Lists and Lists by Andrew Plotkin, Inform 6. (Partially allows derivative works: "The Scheme interpreter source may be freely used, modified, and incorporated into other works." A Scheme interpreter and coding exercise.)

No Licensing Information

• Competition '99 by Lucian Paul Smith, Inform 6 (front-end for the IF Comp).
• ELIZA, adapted by Ricardo Dague to Inform 6 (famous chatbot).
• Fractal Zoomer by Peter De Wachter, Inform 6 (for viewing fractals).
• Journey to Alpha Centauri (In Real Time) by Julian Fleetwood, Inform 6 (look at your screen for 3000 years).
• Life or Death by David S. Glasser, Inform 6 (Game of Life).
• A Tight Spot by Quim K. Holland, Inform 6 (Sokoban).