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INFORM(1) Inform v6.36 - interactive fiction story file compiler INFORM(1)


inform - compile Inform interactive fiction story files to Z-machine or Glulx bytecode


inform [options...] infile [outfile]


inform compiles an Inform version 6 story file (usually with the extension .inf) into Z-machine or Glulx bytecode which can then be executed by a variety of Z-machine or Glulx emulators. If the output filename is not explicitly given on the command line, it will be constructed from the input filename.

inform's mode of operation can be controlled with switches (one or two-character expressions preceded by a dash), path modifiers (starting with a plus sign) and memory strategy modifiers (starting with a dollar sign).


trace assembly-language (without hex dumps; see -t)
more concise error messages
contract double spaces after full stops in text
contract double spaces after exclamation and question marks, too
economy mode (slower): make use of declared abbreviations
frequencies mode: show how useful abbreviations are
traces calls to functions (except in the library)
traces calls to all functions
print usage information
ignore default switches set within the file
list objects as constructed
output Infix debugging information to "gameinfo.dbg" (and switch -D on)
list every statement run through Inform
say how much memory has been allocated
print numbers of properties, attributes and actions
print offset addresses
give percentage breakdown of story file
keep quiet about obsolete usages
record all the text to "gametext.txt"
give statistics
trace assembly-language (with full hex dumps; see -a)
work out most useful abbreviations (very very slowly)
compile to a specific Z-code version; the default is 5. Available versions are:
version-3 ("Standard") story file
version-4 ("Plus") story file
version-5 ("Advanced") story file
version-6 (graphical) story file
version-8 (expanded "Advanced") story file
disable warning messages
print # for every 100 lines compiled
trace linking system
print memory map of the Z-machine
use big memory model (for large version-6/version-7 files)
select text character set (defaults to 1):
plain ASCII only
ISO 8859-1 (Latin1)
ISO 8859-2 (Latin2)
ISO 8859-3 (Latin3)
ISO 8859-4 (Latin4)
ISO 8859-5 (Cyrillic)
ISO 8859-6 (Arabic)
ISO 8859-7 (Greek)
ISO 8859-8 (Hebrew)
ISO 8859-9 (Latin5)
Unicode (UTF-8)
insert "Constant DEBUG;" automatically
select error message style (default is Archimedes):
Archimedes-style error messages
Microsoft-style error messages
Macintosh MPW-style error messages
use temporary files to reduce memory consumption
compile a Glulx game file
use Huffman encoding to compress Glulx strings
compile as a Module for future linking
compile strict error-checking at run-time (on by default)
insert "Constant USE_MODULES;" automatically
display version and exit
header extension table is at least n words (n = 3 to 99)
compile with INFIX debugging facilities present


change PATH to this directory
add this directory to the PATH

PATH MODIFIERS (old style)

set Include_Path to this directory
add this directory to Include_Path
change PATH to this directory
add this directory to the PATH


List current memory allocation settings.
explain briefly what SETTING is for
change SETTING to given number
define define SYMBOL as a constant in this story
read in a list of commands (in the format above) from this setup file. See INFORM COMMAND LANGUAGE below


Note: it may be necessary to quote these parameters to prevent your shell from expanding them.

list current memory allocation settings
explain memory setting SETTING (see $list for available parameters)
manually set SETTING to given number
define SYMBOL as a constant in the story
read in a list of commands (in the format above) from this setup file. See INFORM COMMAND LANGUAGE below


The Switches directive, which enables certain compiler switches to be set from within the source file rather than on the compiler command line, has been superseded by a more powerful mechanism. The special comment characters "!%", occurring on the very first line or lines of the source file, enable you to specify Inform Command Language (ICL) commands to control the compilation. For example:

!% -E1G ! Glulx, 'Microsoft' errors
!% -~S ! disable Strict mode
!% +include_path=./test,./,../lib/contrib ! look in 'test' library
Constant STORY "RUINS";

ICL is described in Section 39 of the Inform Designer's Manual. In brief: each line specifies a single command, starting with "-" to define one or more switches, "+" to define a path variable, or "$" to define a memory setting. Comments are introduced by "$". The ICL command "compile" is not permitted at the head of a source file.


inform is not capable of creating story files conforming to versions 1 or 2 of the Z-Machine.
Modules cannot be used with Glulx and are deprecated for Z-Machine.


The canonical documentation for Inform6 is the Inform_Designer's Manual. This work can be browsed at
<> downloaded from
<> and purchased in hardcopy at

Another noteworthy and somewhat more up-to-date resource is the Inform Beginner's Guide. This work can be downloaded at


zcode-interpreter(6) and the manuals and language reference which can be found online at


The various iterations of the Inform language were created by Graham Nelson in 1993.

This manpage was written by Jan Nordholz <> for the Debian Project and altered by David Griffith <>.


The compiler and standard library for Inform6 are licensed under

The traditional Inform license as described by the DM4, or
The Artistic License 2.0 .

Here is the relevant bit from the Inform Designer's Manual, 4th edition:

Copyright on Inform, the program and its source code, its example games and documentation (including this book) is retained by Graham Nelson, who asserts the moral right to be identified as the author under the Copyrights, Designs and Patents Act 1988. Having said this, I am happy for it to be freely distributed to anybody who wants a copy, provided that: (a) distributed copies are not substantially different from those archived by the author, (b) this and other copyright messages are always retained in full, and (c) no profit is involved. (Exceptions to these rules must be negotiated directly with the author.) However, a story file produced with the Inform compiler (and libraries) then belongs to its author, and may be sold for profit if desired, provided that its game banner contains the information that it was compiled by Inform, and the Inform version number.

The Artistic License 2.0 can be found at
and the file ARTISTIC in the Inform6 distribution archive.

2022-02-19 Inform v6.36