§1. The core Inform compiler combines natural-language source text, including natural-language extensions, and precompiled "kits" in order to make the instructions for making a playable story. Inform is internally divided into Stages, numbered 1 to 7:1

§2. These seven stages form a single code base but are packaged up into three command-line tools, not one:

All three tools also use a large library of services: everything from inflecting words to simplifying logical propositions.

§3. The flow of data looks like so, with time running downwards on the page:

    kit sources
  (in Inform 6 code)
        |
        | INTER
       \|/
    precompiled
    Inter trees
        .                main source text    extension source texts
        .                             \           /
        .                              \         /  INFORM7 Stage 1 or INBUILD
        .                               \       /
        .                               \|/   \|/
        .                              syntax tree
        .                                   |
        .                                   |  INFORM7 Stages 2 to 4/5
        .                                   |
        . . . . . . . precompiled          \|/
                      Inter trees      Inter tree
                            \              /
                             \            /  INFORM7 Stage 6 or INTER
                             \|/        \|/
                        single linked Inter tree
                            /       |       \
                           /        |        \   INFORM7 Stage 7 or INTER
                         \|/       \|/       \|/
                 Inform 6 code   C code     index mini-website
                          :         :
                 INFORM6  :         :  CLANG or GCC
                         \:/       \:/
                   story file   executable
                          :
                 INBLORB  :
                         \:/
                 playable website

§4. The code base is subdivided into "modules". There are around 30, from five sources:

§5. The full breakdown of the three compiler tools into modules is as follows. An o means that the tool is the owner of the module in question; a x means that it imports the module from somewhere else.

WEB                 ACTIVE STAGES   INWEB    SERVICES    INBUILD     INFORM7     INTER
inbuild cli         Before            -         -           o           -          -
inform7 cli         Before            -         -           -           o          -
inter cli           Before            -         -           -           -          o
supervisor module   Stage 1           -         -           o           x          -
core module         Stage 2           -         -           -           o          -
assertions module   Stage 3           -         -           -           o          -
values module       Stage 3           -         -           -           o          -
knowledge module    Stage 3           -         -           -           o          -
if module           Stage 3           -         -           -           o          -
multimedia module   Stage 3           -         -           -           o          -
imperative module   Stage 4           -         -           -           o          -
runtime module      Stage 4           -         -           -           o          -
bytecode module     Stage 5           -         -           -           x          o
building module     Stage 5           -         -           -           x          o
pipeline module     Stage 6           -         -           -           x          o
final module        Stage 7           -         -           -           x          o
index module        Stage 7           -         -           -           x          o
linguistics service Throughout        -         o           -           x          -
calculus service    Throughout        -         o           -           x          -
kinds service       Throughout        -         o           -           x          -
lexicon service     Throughout        -         o           -           x          -
inflections service Throughout        -         o           -           x          -
problems service    Throughout        -         o           -           x          -
syntax service      Throughout        -         o           x           x          -
words service       Throughout        -         o           x           x          x
arch service        Throughout        -         o           x           x          x
html service        Throughout        -         o           x           x          x
foundation library  Throughout        o         -           x           x          x

The executables otherwise contain only a few POSIX or Windows-related functions for file and directory handling, and functions from the standard C library. There are, therefore, no external dependencies.