diff --git a/css/css-writing-modes/tools/generators/README.md b/css/css-writing-modes/tools/generators/README.md
deleted file mode 100644
index 9bf89de07a89719..000000000000000
--- a/css/css-writing-modes/tools/generators/README.md
+++ /dev/null
@@ -1,24 +0,0 @@
-Generators
-==========
-
-Following test files are generated by the programs in this directory:
-* orthogonal-parent-shrink-to-fit-001
-
-## Setup
-
-1. Install node.js.
-2. Change the current directory to this directory.
-3. Type the following commands:
-```
-npm install
-```
-4. (optional) Install gulp globally so it'll be on your path:
-```
-sudo npm install -g gulp
-```
-
-## Generate Test Files
-
-```
-gulp
-```
diff --git a/css/css-writing-modes/tools/generators/generate.py b/css/css-writing-modes/tools/generators/generate.py
new file mode 100755
index 000000000000000..6d54eebc0506dd1
--- /dev/null
+++ b/css/css-writing-modes/tools/generators/generate.py
@@ -0,0 +1,86 @@
+#!/usr/bin/env python3
+import os
+import string
+
+from typing import List, Tuple
+
+test_template = """<h3>{number}: {title}</h3>
+<div class="test">
+    {html}
+</div>"""
+
+
+def generate_test_list() -> List[Tuple[str, str]]:
+    test_list = [];
+    outers = [
+        ["inline-block", '<div class="inline-block">', '</div><span class="next">ZZ</span>'],
+        ["float", '<div class="float">', '</div><span class="next">ZZ</span>'],
+        ["table-cell", '<table><tr><td>', '</td><td class="next">ZZ</td></tr></table>']];
+    middles = [
+        None,
+        ["inline-block", '<div class="inline-block">', '</div>']];
+    targets = [
+        ["block", '<div class="target">HH</div>'],
+        ["inline", '<span class="target">HH</span>'],
+        ["block with borders", '<div class="target border">HHH</div>'],
+        ["inline with borders", '<span class="target border">HHH</span>']];
+    for outer in outers:
+        for middle in middles:
+            for target in targets:
+                title = target[0];
+                html = target[1];
+                if middle is not None:
+                    title += " in " + middle[0];
+                    html = middle[1] + html + middle[2];
+                title = "Shrink-to-fit " + outer[0] + " with a child of orthogonal " + title;
+                html = outer[1] + html + outer[2];
+                test_list.append((title, html));
+    return test_list
+
+
+def read_template() -> str:
+    with open("template.html") as f:
+        return f.read()
+
+
+def main():
+    template = read_template()
+    test_list = generate_test_list()
+
+    dest_dir = os.path.abspath(
+        os.path.join(os.path.dirname(os.path.abspath(__file__)),
+                     os.path.pardir,
+                     os.path.pardir))
+
+    for index in range(-1, len(test_list)):
+        if index == -1:
+            offset = 0
+            suffix = ""
+            tests = test_list
+            title = "Shrink-to-fit with orthogonal children"
+            flags = " combo"
+        else:
+            offset = index
+            suffix = string.ascii_letters[index]
+            tests = [test_list[index]]
+            title = tests[0][0]
+            flags = ""
+
+        filename = f"orthogonal-parent-shrink-to-fit-001{suffix}.html"
+
+        tests_data = []
+        for idx, (test_title, html) in enumerate(tests):
+            number = offset + idx + 1
+            tests_data.append(test_template.format(number=number,
+                                                   title=test_title,
+                                                   html=html))
+
+        output = template.replace("{{title}}", title)
+        output = output.replace("{{flags}}", flags)
+        output = output.replace("{{tests}}", "\n".join(tests_data))
+        with open(os.path.join(dest_dir, filename), "w") as f:
+            f.write(output)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/css/css-writing-modes/tools/generators/gulpfile.js b/css/css-writing-modes/tools/generators/gulpfile.js
deleted file mode 100644
index f364024084dc0c2..000000000000000
--- a/css/css-writing-modes/tools/generators/gulpfile.js
+++ /dev/null
@@ -1,79 +0,0 @@
-'use strict';
-
-var browserSync = null;
-var gulp = require("gulp");
-var ejs = require("gulp-ejs");
-var rename = require("gulp-rename");
-var minimist = require('minimist');
-var argv = minimist(process.argv.slice(2));
-
-gulp.task("default", [
-  "orthogonal-parent-shrink-to-fit",
-]);
-
-gulp.task("test", ["browser-sync", "watch"]);
-
-gulp.task("watch", function () {
-  gulp.watch("orthogonal-parent-shrink-to-fit.ejs", ["orthogonal-parent-shrink-to-fit"]);
-});
-
-gulp.task("browser-sync", function () {
-  if (!browserSync)
-    browserSync = require("browser-sync");
-  browserSync({
-    server: {
-      baseDir: "../../..",
-      directory: true,
-    },
-    startPath: "css-writing-modes-3/",
-  });
-});
-
-function reload() {
-  if (browserSync)
-    browserSync.reload();
-}
-
-gulp.task("server", function () {
-  var connect = require("connect");
-  var serveIndex = require("serve-index");
-  var serveStatic = require("serve-static");
-  var directory = "../../..";
-  var port = 8000;
-  connect()
-    .use(serveIndex(directory))
-    .use(serveStatic(directory))
-    .listen(port);
-  console.log("Listening on port " + port);
-})
-
-gulpTaskFromTemplateWithAffixes("orthogonal-parent-shrink-to-fit", "-001", -1, 24);
-
-gulp.task("update", function () {
-  const unicodeData = require('./unicode-data.js');
-  unicodeData.copyToLocal();
-});
-
-function gulpTaskFromTemplateWithAffixes(name, suffix, min, lim) {
-  if (argv.nocombo && min < 0)
-    min = 0;
-  if (argv.nochild && lim > 0)
-    lim = 0;
-  gulp.task(name, function () {
-    for (var i = min; i < lim; ++i) {
-      gulp.src(name + ".ejs")
-        .pipe(ejs({ index: i }))
-        .pipe(rename(name + suffix + affixFromIndex(i) + ".html"))
-        .pipe(gulp.dest("../.."));
-    }
-    reload();
-  });
-}
-
-function affixFromIndex(index) {
-  if (index < 0)
-    return "";
-  if (index >= 26)
-    throw new Error("Affix index too large (" + index + ")");
-  return String.fromCharCode("a".charCodeAt(0) + index);
-}
diff --git a/css/css-writing-modes/tools/generators/package.json b/css/css-writing-modes/tools/generators/package.json
deleted file mode 100644
index 8046cf4240aa37e..000000000000000
--- a/css/css-writing-modes/tools/generators/package.json
+++ /dev/null
@@ -1,23 +0,0 @@
-{
-  "name": "generators",
-  "version": "1.0.0",
-  "description": "",
-  "main": "gulpfile.js",
-  "dependencies": {},
-  "devDependencies": {
-    "browser-sync": "^2.10.1",
-    "connect": "^3.4.0",
-    "ejs": "^2.3.1",
-    "gulp": "^3.8.11",
-    "gulp-ejs": "^1.1.0",
-    "gulp-rename": "^1.2.2",
-    "minimist": "^1.1.1",
-    "serve-index": "^1.7.2",
-    "serve-static": "^1.10.0"
-  },
-  "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
-  },
-  "author": "",
-  "license": "ISC"
-}
diff --git a/css/css-writing-modes/tools/generators/orthogonal-parent-shrink-to-fit.ejs b/css/css-writing-modes/tools/generators/template.html
similarity index 59%
rename from css/css-writing-modes/tools/generators/orthogonal-parent-shrink-to-fit.ejs
rename to css/css-writing-modes/tools/generators/template.html
index 043cbaf747a7931..74fc1852320b3a9 100644
--- a/css/css-writing-modes/tools/generators/orthogonal-parent-shrink-to-fit.ejs
+++ b/css/css-writing-modes/tools/generators/template.html
@@ -1,48 +1,9 @@
 <!DOCTYPE html>
 <meta charset="utf-8">
-<%
-var testlist = [];
-var outers = [
-    ["inline-block", '<div class="inline-block">', '</div><span class="next">ZZ</span>'],
-    ["float", '<div class="float">', '</div><span class="next">ZZ</span>'],
-    ["table-cell", '<table><tr><td>', '</td><td class="next">ZZ</td></tr></table>']];
-var middles = [
-    null,
-    ["inline-block", '<div class="inline-block">', '</div>']];
-var targets = [
-    ["block", '<div class="target">HH</div>'],
-    ["inline", '<span class="target">HH</span>'],
-    ["block with borders", '<div class="target border">HHH</div>'],
-    ["inline with borders", '<span class="target border">HHH</span>']];
-for (var outer of outers) {
-    for (var middle of middles) {
-        for (var target of targets) {
-            var title = target[0];
-            var html = target[1];
-            if (middle) {
-                title += " in " + middle[0];
-                html = middle[1] + html + middle[2];
-            }
-            title = "Shrink-to-fit " + outer[0] + " with a child of orthogonal " + title;
-            html = outer[1] + html + outer[2];
-            testlist.push([title, html]);
-        }
-    }
-}
-var min, limit, title;
-if (index < 0) {
-    min = 0;
-    limit = testlist.length;
-    title = "Shrink-to-fit with orthogonal children"
-} else {
-    min = index;
-    limit = index + 1;
-    title = testlist[index][0];
-}
-%><title>CSS Writing Modes Test: <%= title %></title>
+<title>CSS Writing Modes Test: {{title}}</title>
 <link rel="help" href="http://www.w3.org/TR/css-writing-modes-3/#orthogonal-flows" title="7.3. Orthogonal Flows">
-<meta name="assert" content="<%= title %>">
-<meta name="flags" content="ahem dom<%= index < 0 ? ' combo' : ''%>">
+<meta name="assert" content="{{title}}">
+<meta name="flags" content="ahem dom{{flags}}">
 <link rel="author" title="Koji Ishii" href="mailto:kojiishi@gmail.com">
 <link rel="reviewer" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/"> <!-- 2015-12-23 -->
 <script src="/resources/testharness.js"></script>
@@ -88,13 +49,8 @@
 <div id="container">
 <p>Test passes if the X-position of the <b>left</b> edge of the orange box and the <b>right</b> edge of the blue box are the same.
 <p>If script is enabled, there should be one or more PASS and no FAIL.
-<% for (var i = min; i < limit; ++i) {
-    var test = testlist[i];
-%><h3><%= (i + 1) + ": " + test[0] %></h3>
-<div class="test">
-    <%- test[1] %>
+{{tests}}
 </div>
-<% } %></div>
 <script>
 if (window.location.search == "?wait") {
     console.log("Sleeping 5 secs for debug");
diff --git a/lint.ignore b/lint.ignore
index 056bbd0c2302441..c8792f5c1af97ec 100644
--- a/lint.ignore
+++ b/lint.ignore
@@ -452,7 +452,7 @@ INDENT TABS: css/WOFF2/*
 CONSOLE: css/css-shapes/shape-outside/supported-shapes/support/test-utils.js
 CONSOLE: css/css-values/viewport-units-css2-001.html
 CONSOLE: css/css-writing-modes/orthogonal-parent-shrink-to-fit-001*.html
-CONSOLE: css/css-writing-modes/tools/generators/gulpfile.js
+CONSOLE: css/css-writing-modes/tools/generators/template.html
 
 TRAILING WHITESPACE: css/css-fonts/support/fonts/gsubtest-lookup3.ufo/features.fea
 
@@ -492,6 +492,7 @@ SET TIMEOUT: css/css-writing-modes/orthogonal-parent-shrink-to-fit-001v.html
 SET TIMEOUT: css/css-writing-modes/orthogonal-parent-shrink-to-fit-001w.html
 SET TIMEOUT: css/css-writing-modes/orthogonal-parent-shrink-to-fit-001x.html
 SET TIMEOUT: css/css-writing-modes/support/text-orientation.js
+SET TIMEOUT: css/css-writing-modes/tools/generators/template.html
 SET TIMEOUT: css/CSS2/backgrounds/background-root-101.xht
 SET TIMEOUT: css/CSS2/backgrounds/background-root-102.xht
 SET TIMEOUT: css/CSS2/backgrounds/background-root-103.xht
diff --git a/tools/ci/jobs.py b/tools/ci/jobs.py
index 5b2ef277a96566a..44de9fe1ad07867 100644
--- a/tools/ci/jobs.py
+++ b/tools/ci/jobs.py
@@ -35,6 +35,7 @@
     "update_built": ["update-built-tests\\.sh",
                      "conformance-checkers/",
                      "css/css-ui/",
+                     "css/css-writing-modes/",
                      "html/",
                      "infrastructure/",
                      "mimesniff/"],
diff --git a/tools/ci/update_built.py b/tools/ci/update_built.py
index 44b950b0e886662..8e0f18589de5cc7 100644
--- a/tools/ci/update_built.py
+++ b/tools/ci/update_built.py
@@ -17,6 +17,7 @@
                              "conformance-checkers/tools/url.py"],
     "css-images": ["css/css-images/tools/generate_object_view_box_tests.py"],
     "css-ui": ["css/css-ui/tools/appearance-build-webkit-reftests.py"],
+    "css-writing-modes": ["css/css-writing-modes/tools/generators/generate.py"],
     # FIXME: https://github.com/web-platform-tests/wpt/issues/32060
     # "css-text": ["css/css-text/line-breaking/tools/generate-segment-break-transformation-rules-tests.py"],
     # "css-text-decor": ["css/css-text-decor/tools/generate-text-emphasis-line-height-tests.py",