diff --git a/ini-mode.el b/ini-mode.el
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+;;; ini-mode.el --- major mode for INI  -*- lexical-binding:t -*-
+
+;; Copyright (C) 2024 Jeremy Baxter
+
+;; Author: Jeremy Baxter <jeremy@baxters.nz>
+;; Maintainer: Jeremy Baxter <jeremy@baxters.nz>
+;; Created: July 2024
+;; Keywords: ini
+
+;; This file is not part of GNU Emacs.
+
+;; ini-mode.el is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+;;
+;; ini-mode.el is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with ini-mode.el.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; ini-mode.el provides `ini-mode', an implementation of a simple
+;; font-locking major mode for INI.
+
+;; TODO: fix section keys refusing to highlight initially
+
+;;; Code:
+
+(require 'font-lock)
+
+(defvar ini-mode-font-lock-keywords
+  '(("\\([#;].*$\\)" . font-lock-comment-face)
+    ("[ \t]*\\[\\(.+\\)\\]" . 'font-lock-type-face)
+    ("\\(^[^=]+\\)" . 'font-lock-keyword-face)
+    ("=\\(.+$\\)" 1 'font-lock-string-face))
+  "Keywords for font locking in `ini-mode'.")
+
+(define-derived-mode ini-mode nil "INI"
+  "Major mode for editing INI."
+
+  (font-lock-mode)
+  (font-lock-add-keywords nil ini-mode-font-lock-keywords))
+
+(provide 'ini-mode)
+
+;;; ini-mode.el ends here