diff --git a/modules/app/regex/autoload.el b/modules/app/regex/autoload.el
new file mode 100644
index 000000000..8b58505ea
--- /dev/null
+++ b/modules/app/regex/autoload.el
@@ -0,0 +1,180 @@
+;;; app/regex/autoload.el
+
+(defvar +regex--text-buffer nil)
+(defvar +regex--expr-buffer nil)
+(defvar +regex--groups-buffer nil)
+
+;;
+(defface +regex-match-0-face
+  '((t (:foreground "Black" :background "Red" :bold t)))
+  ""
+  :group 'doom)
+
+(defface +regex-match-1-face
+  '((t (:foreground "Black" :background "Blue" :bold t)))
+  ""
+  :group 'doom)
+
+(defface +regex-match-2-face
+  '((t (:foreground "Black" :background "Green" :bold t)))
+  ""
+  :group 'doom)
+
+(defvar +regex-faces
+  '(+regex-match-0-face +regex-match-1-face +regex-match-2-face)
+  "TODO")
+
+;;
+(defvar +regex-mode-map
+  (let ((map (make-sparse-keymap)))
+    (evil-define-key* 'normal map
+      "\C-c\C-c" #'+regex-update-buffers
+      "\C-c\C-k" #'+regex/quit)
+    map)
+  "TODO")
+
+(define-minor-mode +regex-mode
+  "TODO"
+  :init-value nil
+  :global nil
+  :lighter ""
+  :keymap +regex-mode-map
+  (if +regex-mode
+      (add-hook 'after-change-functions #'+regex-update-buffers nil t)
+    (remove-hook 'after-change-functions #'+regex-update-buffers t)))
+
+;;;###autoload
+(defun =regex (&optional dummy-text)
+  "Start the Regex IDE."
+  (interactive "P")
+  (condition-case ex
+      (progn
+        (setq +regex--expr-buffer (get-buffer-create "*doom-regex*")
+              +regex--text-buffer (if dummy-text (get-buffer-create "*doom-regex-text*") (current-buffer))
+              +regex--groups-buffer (get-buffer-create "*doom-regex-groups*"))
+        (when dummy-text
+          (+workspace-switch +regex-workspace-name t)
+          (switch-to-buffer +regex--text-buffer)
+          (insert +regex-dummy-text))
+        (doom-popup-buffer +regex--groups-buffer)
+        (doom-popup-buffer +regex--expr-buffer)
+        (with-current-buffer +regex--expr-buffer
+          (conf-mode)
+          (doom-buffer-mode +1)
+          (rainbow-delimiters-mode +1)
+          (linum-mode -1)
+          (+regex-mode +1)
+          (text-scale-set 3)))
+    ('error
+     (+regex/quit)
+     (error "Failed to open the Regexp IDE: %s" ex))))
+
+;;;###autoload
+(defun +regex/quit ()
+  "TODO"
+  (interactive)
+  (kill-buffer +regex--expr-buffer)
+  (kill-buffer +regex--groups-buffer)
+  (when (and +regex--text-buffer (buffer-live-p +regex--text-buffer))
+    (with-current-buffer +regex--text-buffer
+      (+regex-mode -1)
+      (remove-overlays)))
+  (setq +regex--expr-buffer nil
+        +regex--text-buffer nil
+        +regex--groups-buffer nil)
+  (when (equal (+workspace-current-name) +regex-workspace-name)
+    (kill-buffer +regex--text-buffer)
+    (+workspace/delete +regex-workspace-name)))
+
+;;;###autoload
+(defun +regex-update-buffers (&optional beg end len)
+  (interactive)
+  (let ((regex (with-current-buffer +regex--expr-buffer (buffer-string))))
+    (when (> (length regex) 0)
+      (with-current-buffer +regex--groups-buffer
+        (erase-buffer))
+      (with-current-buffer +regex--text-buffer
+        (remove-overlays)
+        (save-excursion
+          (ignore-errors
+            (goto-char (point-min))
+            (pcase +regex-default-backend
+              ('emacs (+regex-backend-emacs regex))
+              ('perl  (+regex-backend-perl regex))))))
+      (with-current-buffer +regex--groups-buffer
+        (goto-char (point-min))))))
+
+
+;; --- backends ---------------------------
+
+(defun +regex--render-perl (regex sample)
+  "From <https://github.com/jwiegley/regex-tool>"
+  (with-temp-buffer
+    (unless (string-match-p "^/.+/[gm]*$" regex)
+      (setq regex (concat "/" regex "/g")))
+    (insert (format "@lines = <DATA>;
+$line = join(\"\", @lines);
+print \"(\";
+while ($line =~ m%smg) {
+  print \"(\", length($`), \" \", length($&), \" \";
+  for $i (1 .. 20) {
+    if ($$i) {
+      my $group = $$i;
+      $group =~ s/([\\\\\"])/\\\\\\1/g;
+      print \"(\", $i, \" . \\\"\", $group, \"\\\") \";
+    }
+  }
+  print \")\";
+}
+print \")\";
+__DATA__
+%s" regex sample))
+    (call-process-region (point-min) (point-max) "perl" t t)
+    (goto-char (point-min))
+    (read (current-buffer))))
+
+;;;###autoload
+(defun +regex-backend-perl (regex)
+  "TODO"
+  (let ((results (+regex--render-perl regex (buffer-string)))
+        (i 0))
+    (dolist (result results)
+      (let ((offset (nth 0 result))
+            (length (nth 1 result))
+            (matches (nthcdr 2 result)))
+        (overlay-put (make-overlay (1+ offset) (+ offset length 1))
+                     'face (nth (mod i 3) +regex-faces))
+        (cl-incf i)
+        (let ((match-zero (buffer-substring (1+ offset) (+ offset length 1))))
+          (with-current-buffer +regex--groups-buffer
+            (insert (format "Group 0: '%s'\n" match-zero))))
+        (dolist (match matches)
+          (with-current-buffer +regex--groups-buffer
+            (goto-char (point-max))
+            (insert (format "Group %d: '%s'\n" (car match)
+                            (cdr match)))))
+        (with-current-buffer +regex--groups-buffer
+          (insert ?\n))))))
+
+;;;###autoload
+(defun +regex-backend-emacs (regex)
+  "TODO"
+  (let ((i 0)
+        pos)
+    (while (and (setq pos (point))
+                (re-search-forward regex nil t))
+      (if (= (point) pos)
+          (forward-char 1)
+        (overlay-put (make-overlay (match-beginning 0)
+                                   (match-end 0))
+                     'face (nth (mod i 3) +regex-faces))
+        (cl-incf i)
+        (dotimes (i 10)
+          (when-let (text (match-string i))
+            (save-match-data
+              (with-current-buffer +regex--groups-buffer
+                (goto-char (point-max))
+                (insert (format "Group %d: '%s'\n" i text))))))
+        (with-current-buffer +regex--groups-buffer
+          (insert ?\n))))))
+
diff --git a/modules/app/regex/config.el b/modules/app/regex/config.el
new file mode 100644
index 000000000..9b124f729
--- /dev/null
+++ b/modules/app/regex/config.el
@@ -0,0 +1,38 @@
+;;; app/regex/config.el
+
+;; Provides a Regex IDE, invoked by `=regex'. If opened with C-u, opens in a
+;; separate frame with a dummy text buffer.
+;;
+;; WARNING: THIS IS A WORK IN PROGRESS
+
+(defvar +regex-workspace-name "*regex*"
+  "TODO")
+
+(defvar +regex-default-backend 'emacs
+  "The backend used to process regular expressions.
+The `emacs' backend handles regular expressions directly.
+The `perl' backend talks to a perl subprocess to do the handling.")
+
+(defvar +regex-dummy-text
+  "Welcome to DOOM Emacs, proudly hosted by the demons of hell!
+
+Edit the Expression & Text to see matches. Roll over matches or the expression
+for details. Undo mistakes with ctrl-z. Save Favorites & Share expressions with
+friends or the Community. Explore your results with Tools. A full Reference &
+Help is available in the Library, or watch the video Tutorial.
+
+Sample text for testing:
+abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ
+0123456789 _+-.,!@#$%^&*();\/|<>\"'
+12345 -98.7 3.141 .6180 9,000 +42
+555.123.4567	+1-(800)-555-2468
+foo@demo.net	bar.ba@test.co.uk
+www.demo.com	http://foo.co.uk/
+http://regexr.com/foo.html?q=bar
+https://mediatemple.net"
+  "TODO")
+
+(set! :popup
+  '("*doom-regex*" :size 4 :select t :noesc t :autokill t)
+  '("*doom-regex-groups*" :align left :size 30 :noselect t :noesc t :autokill t))
+