From 8158628a9085c6c989e82c9b2631c8ecc819e0a7 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Thu, 28 Sep 2023 10:07:26 +0200
Subject: [PATCH 1/3] [api-minor] Stop building a minified default viewer

The minified default viewer has never been distributed in either official releases or through pdfjs-dist, which means that it's most likely unused, and it's has never been tested nor actively maintained.
---
 gulpfile.mjs                     | 39 --------------------------------
 web/viewer-snippet-minified.html |  3 ---
 web/viewer.html                  |  4 +---
 3 files changed, 1 insertion(+), 45 deletions(-)
 delete mode 100644 web/viewer-snippet-minified.html

diff --git a/gulpfile.mjs b/gulpfile.mjs
index 8cc36bd2e6757..d47533cbc19e8 100644
--- a/gulpfile.mjs
+++ b/gulpfile.mjs
@@ -1154,38 +1154,9 @@ function buildMinified(defines, dir) {
     createMainBundle(defines).pipe(gulp.dest(dir + "build")),
     createWorkerBundle(defines).pipe(gulp.dest(dir + "build")),
     createSandboxBundle(defines).pipe(gulp.dest(dir + "build")),
-    createWebBundle(defines, {
-      defaultPreferencesDir: defines.SKIP_BABEL
-        ? "minified/"
-        : "minified-legacy/",
-    }).pipe(gulp.dest(dir + "web")),
     createImageDecodersBundle(
       builder.merge(defines, { IMAGE_DECODERS: true })
     ).pipe(gulp.dest(dir + "image_decoders")),
-    gulp.src(COMMON_WEB_FILES, { base: "web/" }).pipe(gulp.dest(dir + "web")),
-    gulp
-      .src(["web/locale/*/viewer.properties", "web/locale/locale.properties"], {
-        base: "web/",
-      })
-      .pipe(gulp.dest(dir + "web")),
-    createCMapBundle().pipe(gulp.dest(dir + "web/cmaps")),
-    createStandardFontBundle().pipe(gulp.dest(dir + "web/standard_fonts")),
-
-    preprocessHTML("web/viewer.html", defines).pipe(gulp.dest(dir + "web")),
-    preprocessCSS("web/viewer.css", defines)
-      .pipe(
-        postcss([
-          postcssDirPseudoClass(),
-          discardCommentsCSS(),
-          postcssNesting(),
-          autoprefixer(AUTOPREFIXER_CONFIG),
-        ])
-      )
-      .pipe(gulp.dest(dir + "web")),
-
-    gulp
-      .src("web/compressed.tracemonkey-pldi-09.pdf")
-      .pipe(gulp.dest(dir + "web")),
   ]);
 }
 
@@ -1200,10 +1171,6 @@ async function parseMinified(dir) {
   const pdfImageDecodersFile = fs
     .readFileSync(dir + "/image_decoders/pdf.image_decoders.js")
     .toString();
-  const viewerFiles = {
-    "pdf.js": pdfFile,
-    "viewer.js": fs.readFileSync(dir + "/web/viewer.js").toString(),
-  };
 
   console.log();
   console.log("### Minifying js files");
@@ -1218,10 +1185,6 @@ async function parseMinified(dir) {
     keep_fnames: true,
   };
 
-  fs.writeFileSync(
-    dir + "/web/pdf.viewer.js",
-    (await minify(viewerFiles, options)).code
-  );
   fs.writeFileSync(
     dir + "/build/pdf.min.js",
     (await minify(pdfFile, options)).code
@@ -1242,8 +1205,6 @@ async function parseMinified(dir) {
   console.log();
   console.log("### Cleaning js files");
 
-  fs.unlinkSync(dir + "/web/viewer.js");
-  fs.unlinkSync(dir + "/web/debugger.js");
   fs.unlinkSync(dir + "/build/pdf.js");
   fs.unlinkSync(dir + "/build/pdf.worker.js");
   fs.unlinkSync(dir + "/build/pdf.sandbox.js");
diff --git a/web/viewer-snippet-minified.html b/web/viewer-snippet-minified.html
deleted file mode 100644
index 4529f189c3610..0000000000000
--- a/web/viewer-snippet-minified.html
+++ /dev/null
@@ -1,3 +0,0 @@
-<!-- This snippet is used in production (included from viewer.html) -->
-<link rel="resource" type="application/l10n" href="locale/locale.properties">
-<script src="pdf.viewer.js"></script>
diff --git a/web/viewer.html b/web/viewer.html
index cd1f6f50e6a02..95382b72704e9 100644
--- a/web/viewer.html
+++ b/web/viewer.html
@@ -33,8 +33,6 @@
 <!--#include viewer-snippet-firefox-extension.html-->
 <!--#elif CHROME-->
 <!--#include viewer-snippet-chrome-extension.html-->
-<!--#elif MINIFIED-->
-<!--#include viewer-snippet-minified.html-->
 <!--#else-->
 <!--#include viewer-snippet.html-->
 <!--#endif-->
@@ -47,7 +45,7 @@
 
 <!--#if MOZCENTRAL-->
 <!--<script src="resource://pdf.js/web/viewer.js"></script>-->
-<!--#elif !MINIFIED-->
+<!--#elif !MOZCENTRAL-->
 <!--<script src="viewer.js"></script>-->
 <!--#elif /* Development mode. */-->
     <link rel="resource" type="application/l10n" href="locale/locale.properties">

From 0a970ee4434e62ed9ab5f134a9fc86ba8da81247 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Sat, 30 Sep 2023 13:25:47 +0200
Subject: [PATCH 2/3] [api-major] Remove the `fallbackWorkerSrc` functionality
 in browsers

The user should *always* provide a correct `GlobalWorkerOptions.workerSrc` value when using the PDF.js library in browser environments. Note that the fallback:
 - Has been deprecated ever since PR 11418, first released in version `2.4.456` over three years ago.
 - Was always a best-effort solution, with no guarantees that it'd actually work correctly.
 - With upcoming changes, w.r.t. outputting JavaScript modules, it'd now be more diffiult to determine the correct value.
---
 src/display/api.js | 27 ++++-----------------------
 1 file changed, 4 insertions(+), 23 deletions(-)

diff --git a/src/display/api.js b/src/display/api.js
index 43300b05279be..14382074f381d 100644
--- a/src/display/api.js
+++ b/src/display/api.js
@@ -45,7 +45,6 @@ import {
   SerializableEmpty,
 } from "./annotation_storage.js";
 import {
-  deprecated,
   DOMCanvasFactory,
   DOMCMapReaderFactory,
   DOMFilterFactory,
@@ -1984,7 +1983,6 @@ class LoopbackPort {
 
 const PDFWorkerUtil = {
   isWorkerDisabled: false,
-  fallbackWorkerSrc: null,
   fakeWorkerId: 0,
 };
 if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
@@ -1993,17 +1991,9 @@ if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
     // Workers aren't supported in Node.js, force-disabling them there.
     PDFWorkerUtil.isWorkerDisabled = true;
 
-    PDFWorkerUtil.fallbackWorkerSrc = PDFJSDev.test("LIB")
+    GlobalWorkerOptions.workerSrc ||= PDFJSDev.test("LIB")
       ? "../pdf.worker.js"
       : "./pdf.worker.js";
-  } else if (typeof document === "object") {
-    const pdfjsFilePath = document?.currentScript?.src;
-    if (pdfjsFilePath) {
-      PDFWorkerUtil.fallbackWorkerSrc = pdfjsFilePath.replace(
-        /(\.(?:min\.)?js)(\?.*)?$/i,
-        ".worker$1$2"
-      );
-    }
   }
 
   // Check if URLs have the same origin. For non-HTTP based URLs, returns false.
@@ -2119,7 +2109,7 @@ class PDFWorker {
     // Uint8Array as it arrives on the worker. (Chrome added this with v.15.)
     if (
       !PDFWorkerUtil.isWorkerDisabled &&
-      !PDFWorker._mainThreadWorkerMessageHandler
+      !PDFWorker.#mainThreadWorkerMessageHandler
     ) {
       let { workerSrc } = PDFWorker;
 
@@ -2308,19 +2298,10 @@ class PDFWorker {
     if (GlobalWorkerOptions.workerSrc) {
       return GlobalWorkerOptions.workerSrc;
     }
-    if (
-      (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) &&
-      PDFWorkerUtil.fallbackWorkerSrc !== null
-    ) {
-      if (!isNodeJS) {
-        deprecated('No "GlobalWorkerOptions.workerSrc" specified.');
-      }
-      return PDFWorkerUtil.fallbackWorkerSrc;
-    }
     throw new Error('No "GlobalWorkerOptions.workerSrc" specified.');
   }
 
-  static get _mainThreadWorkerMessageHandler() {
+  static get #mainThreadWorkerMessageHandler() {
     try {
       return globalThis.pdfjsWorker?.WorkerMessageHandler || null;
     } catch {
@@ -2331,7 +2312,7 @@ class PDFWorker {
   // Loads worker code into the main-thread.
   static get _setupFakeWorkerGlobal() {
     const loader = async () => {
-      const mainWorkerMessageHandler = this._mainThreadWorkerMessageHandler;
+      const mainWorkerMessageHandler = this.#mainThreadWorkerMessageHandler;
 
       if (mainWorkerMessageHandler) {
         // The worker was already loaded using e.g. a `<script>` tag.

From 927e50f5d48a67e76f2a51c112ea5a98867822fe Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Thu, 28 Sep 2023 13:00:10 +0200
Subject: [PATCH 3/3] [api-major] Output JavaScript modules in the builds
 (issue 10317)

At this point in time all browsers, and also Node.js, support standard `import`/`export` statements and we can now finally consider outputting modern JavaScript modules in the builds.[1]

In order for this to work we can *only* use proper `import`/`export` statements throughout the main code-base, and (as expected) our Node.js support made this much more complicated since both the official builds and the GitHub Actions-based tests must keep working.[2]
One remaining issue is that the `pdf.scripting.js` file cannot be built as a JavaScript module, since doing so breaks PDF scripting.

Note that my initial goal was to try and split these changes into a couple of commits, however that unfortunately didn't really work since it turned out to be difficult for smaller patches to work correctly and pass (all) tests that way.[3]
This is a classic case of every change requiring a couple of other changes, with each of those changes requiring further changes in turn and the size/scope quickly increasing as a result.

One possible "issue" with these changes is that we'll now only output JavaScript modules in the builds, which could perhaps be a problem with older tools. However it unfortunately seems far too complicated/time-consuming for us to attempt to support both the old and modern module formats, hence the alternative would be to do "nothing" here and just keep our "old" builds.[4]

---
[1] The final blocker was module support in workers in Firefox, which was implemented in Firefox 114; please see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import#browser_compatibility

[2] It's probably possible to further improve/simplify especially the Node.js-specific code, but it does appear to work as-is.

[3] Having partially "broken" patches, that fail tests, as part of the commit history is *really not* a good idea in general.

[4] Outputting JavaScript modules was first requested almost five years ago, see issue 10317, and nowadays there *should* be much better support for JavaScript modules in various tools.
---
 external/dist/webpack.js                  |   5 +-
 gulpfile.mjs                              | 218 +++++++++++-----------
 src/display/api.js                        |  51 +----
 src/display/display_utils.js              |  24 ---
 src/display/node_stream.js                |  15 +-
 src/display/node_utils.js                 |  70 +++++--
 src/pdf.js                                |   2 -
 src/pdf.worker.entry.js                   |   2 +-
 test/driver.js                            |   2 +-
 test/test_slave.html                      |   4 +-
 test/unit/api_spec.js                     |  11 +-
 test/unit/jasmine-boot.js                 |   2 +-
 test/unit/pdf_spec.js                     |   9 +-
 test/unit/scripting_spec.js               |   9 +-
 web/app.js                                |   5 +-
 web/app_options.js                        |   8 +-
 web/generic_scripting.js                  |  17 +-
 web/pdfjs.js                              |   2 -
 web/viewer-geckoview.html                 |   2 +-
 web/viewer-snippet-chrome-extension.html  |   2 +-
 web/viewer-snippet-firefox-extension.html |   2 +-
 web/viewer-snippet.html                   |   2 +-
 web/viewer.html                           |   4 +-
 23 files changed, 227 insertions(+), 241 deletions(-)

diff --git a/external/dist/webpack.js b/external/dist/webpack.js
index 03704cdd4417f..9b944720892d8 100644
--- a/external/dist/webpack.js
+++ b/external/dist/webpack.js
@@ -15,11 +15,12 @@
 
 "use strict";
 
-const pdfjs = require("./build/pdf.js");
+const pdfjs = require("./build/pdf.mjs");
 
 if (typeof window !== "undefined" && "Worker" in window) {
   pdfjs.GlobalWorkerOptions.workerPort = new Worker(
-    new URL("./build/pdf.worker.js", import.meta.url)
+    new URL("./build/pdf.worker.mjs", import.meta.url),
+    { type: "module" }
   );
 }
 
diff --git a/gulpfile.mjs b/gulpfile.mjs
index d47533cbc19e8..cc2624d195f4f 100644
--- a/gulpfile.mjs
+++ b/gulpfile.mjs
@@ -201,6 +201,7 @@ function createWebpackConfig(
     !bundleDefines.LIB &&
     !bundleDefines.TESTING &&
     !disableSourceMaps;
+  const isModule = output.library?.type === "module";
   const skipBabel = bundleDefines.SKIP_BABEL;
 
   // `core-js`, see https://github.com/zloirock/core-js/issues/514,
@@ -216,7 +217,9 @@ function createWebpackConfig(
           { corejs: "3.32.2", shippedProposals: true, useBuiltIns: "usage" },
         ],
       ];
-  const babelPlugins = ["@babel/plugin-transform-modules-commonjs"];
+  const babelPlugins = isModule
+    ? []
+    : ["@babel/plugin-transform-modules-commonjs"];
 
   const plugins = [];
   if (!disableLicenseHeader) {
@@ -225,8 +228,7 @@ function createWebpackConfig(
     );
   }
 
-  const experiments =
-    output.library?.type === "module" ? { outputModule: true } : undefined;
+  const experiments = isModule ? { outputModule: true } : undefined;
 
   // Required to expose e.g., the `window` object.
   output.globalObject = "globalThis";
@@ -296,7 +298,11 @@ function createWebpackConfig(
   }
 
   return {
-    mode: "none",
+    mode: "production",
+    optimization: {
+      mangleExports: false,
+      minimize: false,
+    },
     experiments,
     output,
     performance: {
@@ -388,14 +394,28 @@ function checkChromePreferencesFile(chromePrefsPath, webPrefs) {
   return ret;
 }
 
-function replaceWebpackRequire() {
-  // Produced bundles can be rebundled again, avoid collisions (e.g. in api.js)
-  // by renaming  __webpack_require__ to something else.
-  return replace("__webpack_require__", "__w_pdfjs_require__");
-}
+function tweakWebpackOutput(jsName) {
+  const replacer = ["__non_webpack_import__\\("];
+
+  if (jsName) {
+    replacer.push(
+      " __webpack_exports__ = {};",
+      " __webpack_exports__ = await __webpack_exports__;"
+    );
+  }
+  const regex = new RegExp(`(${replacer.join("|")})`, "gm");
 
-function replaceNonWebpackImport() {
-  return replace("__non_webpack_import__", "import");
+  return replace(regex, match => {
+    switch (match) {
+      case "__non_webpack_import__(":
+        return "import(/* webpackIgnore: true */ ";
+      case " __webpack_exports__ = {};":
+        return ` __webpack_exports__ = globalThis.${jsName} = {};`;
+      case " __webpack_exports__ = await __webpack_exports__;":
+        return ` __webpack_exports__ = globalThis.${jsName} = await __webpack_exports__;`;
+    }
+    return match;
+  });
 }
 
 function addGlobalExports(amdName, jsName) {
@@ -423,21 +443,16 @@ function addGlobalExports(amdName, jsName) {
 }
 
 function createMainBundle(defines) {
-  const mainAMDName = "pdfjs-dist/build/pdf";
-  const mainOutputName = "pdf.js";
-
   const mainFileConfig = createWebpackConfig(defines, {
-    filename: mainOutputName,
-    library: mainAMDName,
-    libraryTarget: "umd",
-    umdNamedDefine: true,
+    filename: "pdf.mjs",
+    library: {
+      type: "module",
+    },
   });
   return gulp
     .src("./src/pdf.js")
     .pipe(webpack2Stream(mainFileConfig))
-    .pipe(replaceWebpackRequire())
-    .pipe(replaceNonWebpackImport())
-    .pipe(addGlobalExports(mainAMDName, "pdfjsLib"));
+    .pipe(tweakWebpackOutput("pdfjsLib"));
 }
 
 function createScriptingBundle(defines, extraOptions = undefined) {
@@ -457,8 +472,6 @@ function createScriptingBundle(defines, extraOptions = undefined) {
   return gulp
     .src("./src/pdf.scripting.js")
     .pipe(webpack2Stream(scriptingFileConfig))
-    .pipe(replaceWebpackRequire())
-    .pipe(replaceNonWebpackImport())
     .pipe(addGlobalExports(scriptingAMDName, "pdfjsScripting"));
 }
 
@@ -489,9 +502,6 @@ function createTemporaryScriptingBundle(defines, extraOptions = undefined) {
 }
 
 function createSandboxBundle(defines, extraOptions = undefined) {
-  const sandboxAMDName = "pdfjs-dist/build/pdf.sandbox";
-  const sandboxOutputName = "pdf.sandbox.js";
-
   const scriptingPath = TMP_DIR + "pdf.scripting.js";
   // Insert the source as a string to be `eval`-ed in the sandbox.
   const sandboxDefines = builder.merge(defines, {
@@ -502,10 +512,10 @@ function createSandboxBundle(defines, extraOptions = undefined) {
   const sandboxFileConfig = createWebpackConfig(
     sandboxDefines,
     {
-      filename: sandboxOutputName,
-      library: sandboxAMDName,
-      libraryTarget: "umd",
-      umdNamedDefine: true,
+      filename: "pdf.sandbox.mjs",
+      library: {
+        type: "module",
+      },
     },
     extraOptions
   );
@@ -513,36 +523,30 @@ function createSandboxBundle(defines, extraOptions = undefined) {
   return gulp
     .src("./src/pdf.sandbox.js")
     .pipe(webpack2Stream(sandboxFileConfig))
-    .pipe(replaceWebpackRequire())
-    .pipe(replaceNonWebpackImport())
-    .pipe(addGlobalExports(sandboxAMDName, "pdfjsSandbox"));
+    .pipe(tweakWebpackOutput("pdfjsSandbox"));
 }
 
 function createWorkerBundle(defines) {
-  const workerAMDName = "pdfjs-dist/build/pdf.worker";
-  const workerOutputName = "pdf.worker.js";
-
   const workerFileConfig = createWebpackConfig(defines, {
-    filename: workerOutputName,
-    library: workerAMDName,
-    libraryTarget: "umd",
-    umdNamedDefine: true,
+    filename: "pdf.worker.mjs",
+    library: {
+      type: "module",
+    },
   });
   return gulp
     .src("./src/pdf.worker.js")
     .pipe(webpack2Stream(workerFileConfig))
-    .pipe(replaceWebpackRequire())
-    .pipe(replaceNonWebpackImport())
-    .pipe(addGlobalExports(workerAMDName, "pdfjsWorker"));
+    .pipe(tweakWebpackOutput("pdfjsWorker"));
 }
 
 function createWebBundle(defines, options) {
-  const viewerOutputName = "viewer.js";
-
   const viewerFileConfig = createWebpackConfig(
     defines,
     {
-      filename: viewerOutputName,
+      filename: "viewer.mjs",
+      library: {
+        type: "module",
+      },
     },
     {
       defaultPreferencesDir: options.defaultPreferencesDir,
@@ -551,17 +555,19 @@ function createWebBundle(defines, options) {
   return gulp
     .src("./web/viewer.js")
     .pipe(webpack2Stream(viewerFileConfig))
-    .pipe(replaceNonWebpackImport());
+    .pipe(tweakWebpackOutput());
 }
 
 function createGVWebBundle(defines, options) {
-  const viewerOutputName = "viewer-geckoview.js";
   defines = builder.merge(defines, { GECKOVIEW: true });
 
   const viewerFileConfig = createWebpackConfig(
     defines,
     {
-      filename: viewerOutputName,
+      filename: "viewer-geckoview.mjs",
+      library: {
+        type: "module",
+      },
     },
     {
       defaultPreferencesDir: options.defaultPreferencesDir,
@@ -570,43 +576,33 @@ function createGVWebBundle(defines, options) {
   return gulp
     .src("./web/viewer-geckoview.js")
     .pipe(webpack2Stream(viewerFileConfig))
-    .pipe(replaceNonWebpackImport());
+    .pipe(tweakWebpackOutput());
 }
 
 function createComponentsBundle(defines) {
-  const componentsAMDName = "pdfjs-dist/web/pdf_viewer";
-  const componentsOutputName = "pdf_viewer.js";
-
   const componentsFileConfig = createWebpackConfig(defines, {
-    filename: componentsOutputName,
-    library: componentsAMDName,
-    libraryTarget: "umd",
-    umdNamedDefine: true,
+    filename: "pdf_viewer.mjs",
+    library: {
+      type: "module",
+    },
   });
   return gulp
     .src("./web/pdf_viewer.component.js")
     .pipe(webpack2Stream(componentsFileConfig))
-    .pipe(replaceWebpackRequire())
-    .pipe(replaceNonWebpackImport())
-    .pipe(addGlobalExports(componentsAMDName, "pdfjsViewer"));
+    .pipe(tweakWebpackOutput("pdfjsViewer"));
 }
 
 function createImageDecodersBundle(defines) {
-  const imageDecodersAMDName = "pdfjs-dist/image_decoders/pdf.image_decoders";
-  const imageDecodersOutputName = "pdf.image_decoders.js";
-
   const componentsFileConfig = createWebpackConfig(defines, {
-    filename: imageDecodersOutputName,
-    library: imageDecodersAMDName,
-    libraryTarget: "umd",
-    umdNamedDefine: true,
+    filename: "pdf.image_decoders.mjs",
+    library: {
+      type: "module",
+    },
   });
   return gulp
     .src("./src/pdf.image_decoders.js")
     .pipe(webpack2Stream(componentsFileConfig))
-    .pipe(replaceWebpackRequire())
-    .pipe(replaceNonWebpackImport())
-    .pipe(addGlobalExports(imageDecodersAMDName, "pdfjsImageDecoders"));
+    .pipe(tweakWebpackOutput("pdfjsImageDecoders"));
 }
 
 function createCMapBundle() {
@@ -1161,15 +1157,15 @@ function buildMinified(defines, dir) {
 }
 
 async function parseMinified(dir) {
-  const pdfFile = fs.readFileSync(dir + "/build/pdf.js").toString();
+  const pdfFile = fs.readFileSync(dir + "build/pdf.mjs").toString();
   const pdfWorkerFile = fs
-    .readFileSync(dir + "/build/pdf.worker.js")
+    .readFileSync(dir + "build/pdf.worker.mjs")
     .toString();
   const pdfSandboxFile = fs
-    .readFileSync(dir + "/build/pdf.sandbox.js")
+    .readFileSync(dir + "build/pdf.sandbox.mjs")
     .toString();
   const pdfImageDecodersFile = fs
-    .readFileSync(dir + "/image_decoders/pdf.image_decoders.js")
+    .readFileSync(dir + "image_decoders/pdf.image_decoders.mjs")
     .toString();
 
   console.log();
@@ -1183,41 +1179,42 @@ async function parseMinified(dir) {
     },
     keep_classnames: true,
     keep_fnames: true,
+    module: true,
   };
 
   fs.writeFileSync(
-    dir + "/build/pdf.min.js",
+    dir + "build/pdf.min.mjs",
     (await minify(pdfFile, options)).code
   );
   fs.writeFileSync(
-    dir + "/build/pdf.worker.min.js",
+    dir + "build/pdf.worker.min.mjs",
     (await minify(pdfWorkerFile, options)).code
   );
   fs.writeFileSync(
-    dir + "/build/pdf.sandbox.min.js",
+    dir + "build/pdf.sandbox.min.mjs",
     (await minify(pdfSandboxFile, options)).code
   );
   fs.writeFileSync(
-    dir + "image_decoders/pdf.image_decoders.min.js",
+    dir + "image_decoders/pdf.image_decoders.min.mjs",
     (await minify(pdfImageDecodersFile, options)).code
   );
 
   console.log();
   console.log("### Cleaning js files");
 
-  fs.unlinkSync(dir + "/build/pdf.js");
-  fs.unlinkSync(dir + "/build/pdf.worker.js");
-  fs.unlinkSync(dir + "/build/pdf.sandbox.js");
+  fs.unlinkSync(dir + "build/pdf.mjs");
+  fs.unlinkSync(dir + "build/pdf.worker.mjs");
+  fs.unlinkSync(dir + "build/pdf.sandbox.mjs");
 
-  fs.renameSync(dir + "/build/pdf.min.js", dir + "/build/pdf.js");
-  fs.renameSync(dir + "/build/pdf.worker.min.js", dir + "/build/pdf.worker.js");
+  fs.renameSync(dir + "build/pdf.min.mjs", dir + "build/pdf.mjs");
+  fs.renameSync(dir + "build/pdf.worker.min.mjs", dir + "build/pdf.worker.mjs");
   fs.renameSync(
-    dir + "/build/pdf.sandbox.min.js",
-    dir + "/build/pdf.sandbox.js"
+    dir + "build/pdf.sandbox.min.mjs",
+    dir + "build/pdf.sandbox.mjs"
   );
   fs.renameSync(
-    dir + "/image_decoders/pdf.image_decoders.min.js",
-    dir + "/image_decoders/pdf.image_decoders.js"
+    dir + "image_decoders/pdf.image_decoders.min.mjs",
+    dir + "image_decoders/pdf.image_decoders.mjs"
   );
 }
 
@@ -1859,8 +1856,8 @@ gulp.task(
         packageJson().pipe(gulp.dest(TYPESTEST_DIR)),
         gulp
           .src([
-            GENERIC_DIR + "build/pdf.js",
-            GENERIC_DIR + "build/pdf.worker.js",
+            GENERIC_DIR + "build/pdf.mjs",
+            GENERIC_DIR + "build/pdf.worker.mjs",
             SRC_DIR + "pdf.worker.entry.js",
           ])
           .pipe(gulp.dest(TYPESTEST_DIR + "build/")),
@@ -2153,7 +2150,7 @@ function packageJson() {
   const npmManifest = {
     name: DIST_NAME,
     version: VERSION,
-    main: "build/pdf.js",
+    main: "build/pdf.mjs",
     types: "types/src/pdf.d.ts",
     description: DIST_DESCRIPTION,
     keywords: DIST_KEYWORDS,
@@ -2171,7 +2168,6 @@ function packageJson() {
       https: false,
       url: false,
     },
-    format: "amd", // to not allow system.js to choose 'cjs'
     repository: {
       type: "git",
       url: DIST_REPO_URL,
@@ -2230,49 +2226,49 @@ gulp.task(
           .pipe(gulp.dest(DIST_DIR)),
         gulp
           .src([
-            GENERIC_DIR + "build/{pdf,pdf.worker,pdf.sandbox}.js",
-            GENERIC_DIR + "build/{pdf,pdf.worker,pdf.sandbox}.js.map",
+            GENERIC_DIR + "build/{pdf,pdf.worker,pdf.sandbox}.mjs",
+            GENERIC_DIR + "build/{pdf,pdf.worker,pdf.sandbox}.mjs.map",
             SRC_DIR + "pdf.worker.entry.js",
           ])
           .pipe(gulp.dest(DIST_DIR + "build/")),
         gulp
           .src([
-            GENERIC_LEGACY_DIR + "build/{pdf,pdf.worker,pdf.sandbox}.js",
-            GENERIC_LEGACY_DIR + "build/{pdf,pdf.worker,pdf.sandbox}.js.map",
+            GENERIC_LEGACY_DIR + "build/{pdf,pdf.worker,pdf.sandbox}.mjs",
+            GENERIC_LEGACY_DIR + "build/{pdf,pdf.worker,pdf.sandbox}.mjs.map",
             SRC_DIR + "pdf.worker.entry.js",
           ])
           .pipe(gulp.dest(DIST_DIR + "legacy/build/")),
         gulp
-          .src(MINIFIED_DIR + "build/pdf.js")
-          .pipe(rename("pdf.min.js"))
+          .src(MINIFIED_DIR + "build/pdf.mjs")
+          .pipe(rename("pdf.min.mjs"))
           .pipe(gulp.dest(DIST_DIR + "build/")),
         gulp
-          .src(MINIFIED_DIR + "build/pdf.worker.js")
-          .pipe(rename("pdf.worker.min.js"))
+          .src(MINIFIED_DIR + "build/pdf.worker.mjs")
+          .pipe(rename("pdf.worker.min.mjs"))
           .pipe(gulp.dest(DIST_DIR + "build/")),
         gulp
-          .src(MINIFIED_DIR + "build/pdf.sandbox.js")
-          .pipe(rename("pdf.sandbox.min.js"))
+          .src(MINIFIED_DIR + "build/pdf.sandbox.mjs")
+          .pipe(rename("pdf.sandbox.min.mjs"))
           .pipe(gulp.dest(DIST_DIR + "build/")),
         gulp
-          .src(MINIFIED_DIR + "image_decoders/pdf.image_decoders.js")
-          .pipe(rename("pdf.image_decoders.min.js"))
+          .src(MINIFIED_DIR + "image_decoders/pdf.image_decoders.mjs")
+          .pipe(rename("pdf.image_decoders.min.mjs"))
           .pipe(gulp.dest(DIST_DIR + "image_decoders/")),
         gulp
-          .src(MINIFIED_LEGACY_DIR + "build/pdf.js")
-          .pipe(rename("pdf.min.js"))
+          .src(MINIFIED_LEGACY_DIR + "build/pdf.mjs")
+          .pipe(rename("pdf.min.mjs"))
           .pipe(gulp.dest(DIST_DIR + "legacy/build/")),
         gulp
-          .src(MINIFIED_LEGACY_DIR + "build/pdf.worker.js")
-          .pipe(rename("pdf.worker.min.js"))
+          .src(MINIFIED_LEGACY_DIR + "build/pdf.worker.mjs")
+          .pipe(rename("pdf.worker.min.mjs"))
           .pipe(gulp.dest(DIST_DIR + "legacy/build/")),
         gulp
-          .src(MINIFIED_LEGACY_DIR + "build/pdf.sandbox.js")
-          .pipe(rename("pdf.sandbox.min.js"))
+          .src(MINIFIED_LEGACY_DIR + "build/pdf.sandbox.mjs")
+          .pipe(rename("pdf.sandbox.min.mjs"))
           .pipe(gulp.dest(DIST_DIR + "legacy/build/")),
         gulp
-          .src(MINIFIED_LEGACY_DIR + "image_decoders/pdf.image_decoders.js")
-          .pipe(rename("pdf.image_decoders.min.js"))
+          .src(MINIFIED_LEGACY_DIR + "image_decoders/pdf.image_decoders.mjs")
+          .pipe(rename("pdf.image_decoders.min.mjs"))
           .pipe(gulp.dest(DIST_DIR + "legacy/image_decoders/")),
         gulp
           .src(COMPONENTS_DIR + "**/*", { base: COMPONENTS_DIR })
diff --git a/src/display/api.js b/src/display/api.js
index 14382074f381d..2d3837b25f84f 100644
--- a/src/display/api.js
+++ b/src/display/api.js
@@ -51,7 +51,6 @@ import {
   DOMStandardFontDataFactory,
   isDataScheme,
   isValidFetchUrl,
-  loadScript,
   PageViewport,
   RenderingCancelledException,
   StatTimer,
@@ -1986,14 +1985,13 @@ const PDFWorkerUtil = {
   fakeWorkerId: 0,
 };
 if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
-  // eslint-disable-next-line no-undef
-  if (isNodeJS && typeof __non_webpack_require__ === "function") {
+  if (isNodeJS) {
     // Workers aren't supported in Node.js, force-disabling them there.
     PDFWorkerUtil.isWorkerDisabled = true;
 
     GlobalWorkerOptions.workerSrc ||= PDFJSDev.test("LIB")
       ? "../pdf.worker.js"
-      : "./pdf.worker.js";
+      : "./pdf.worker.mjs";
   }
 
   // Check if URLs have the same origin. For non-HTTP based URLs, returns false.
@@ -2126,11 +2124,7 @@ class PDFWorker {
           );
         }
 
-        const worker =
-          typeof PDFJSDev === "undefined" &&
-          !workerSrc.endsWith("/build/pdf.worker.js")
-            ? new Worker(workerSrc, { type: "module" })
-            : new Worker(workerSrc);
+        const worker = new Worker(workerSrc, { type: "module" });
         const messageHandler = new MessageHandler("main", "worker", worker);
         const terminateEarly = () => {
           worker.removeEventListener("error", onWorkerError);
@@ -2312,40 +2306,15 @@ class PDFWorker {
   // Loads worker code into the main-thread.
   static get _setupFakeWorkerGlobal() {
     const loader = async () => {
-      const mainWorkerMessageHandler = this.#mainThreadWorkerMessageHandler;
-
-      if (mainWorkerMessageHandler) {
+      if (this.#mainThreadWorkerMessageHandler) {
         // The worker was already loaded using e.g. a `<script>` tag.
-        return mainWorkerMessageHandler;
-      }
-      if (typeof PDFJSDev === "undefined") {
-        const worker = await import("pdfjs/pdf.worker.js");
-        return worker.WorkerMessageHandler;
-      }
-      if (
-        PDFJSDev.test("GENERIC") &&
-        isNodeJS &&
-        // eslint-disable-next-line no-undef
-        typeof __non_webpack_require__ === "function"
-      ) {
-        // Since bundlers, such as Webpack, cannot be told to leave `require`
-        // statements alone we are thus forced to jump through hoops in order
-        // to prevent `Critical dependency: ...` warnings in third-party
-        // deployments of the built `pdf.js`/`pdf.worker.js` files; see
-        // https://github.com/webpack/webpack/issues/8826
-        //
-        // The following hack is based on the assumption that code running in
-        // Node.js won't ever be affected by e.g. Content Security Policies that
-        // prevent the use of `eval`. If that ever occurs, we should revert this
-        // to a normal `__non_webpack_require__` statement and simply document
-        // the Webpack warnings instead (telling users to ignore them).
-        //
-        // eslint-disable-next-line no-eval
-        const worker = eval("require")(this.workerSrc);
-        return worker.WorkerMessageHandler;
+        return this.#mainThreadWorkerMessageHandler;
       }
-      await loadScript(this.workerSrc);
-      return window.pdfjsWorker.WorkerMessageHandler;
+      const worker =
+        typeof PDFJSDev === "undefined"
+          ? await import("pdfjs/pdf.worker.js")
+          : await __non_webpack_import__(this.workerSrc); // eslint-disable-line no-undef
+      return worker.WorkerMessageHandler;
     };
 
     return shadow(this, "_setupFakeWorkerGlobal", loader());
diff --git a/src/display/display_utils.js b/src/display/display_utils.js
index b902c67c1313f..4b535b73e5664 100644
--- a/src/display/display_utils.js
+++ b/src/display/display_utils.js
@@ -796,29 +796,6 @@ function noContextMenu(e) {
   e.preventDefault();
 }
 
-/**
- * @param {string} src
- * @param {boolean} [removeScriptElement]
- * @returns {Promise<void>}
- */
-function loadScript(src, removeScriptElement = false) {
-  return new Promise((resolve, reject) => {
-    const script = document.createElement("script");
-    script.src = src;
-
-    script.onload = function (evt) {
-      if (removeScriptElement) {
-        script.remove();
-      }
-      resolve(evt);
-    };
-    script.onerror = function () {
-      reject(new Error(`Cannot load script at: ${script.src}`));
-    };
-    (document.head || document.documentElement).append(script);
-  });
-}
-
 // Deprecated API function -- display regardless of the `verbosity` setting.
 function deprecated(details) {
   console.log("Deprecated API usage: " + details);
@@ -1026,7 +1003,6 @@ export {
   isDataScheme,
   isPdfFile,
   isValidFetchUrl,
-  loadScript,
   noContextMenu,
   PageViewport,
   PDFDateString,
diff --git a/src/display/node_stream.js b/src/display/node_stream.js
index 62e72ad0b632a..3a8c34d09f8aa 100644
--- a/src/display/node_stream.js
+++ b/src/display/node_stream.js
@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* globals __non_webpack_require__ */
 
 import {
   AbortException,
@@ -34,7 +33,7 @@ if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
 const fileUriRegex = /^file:\/\/\/[a-zA-Z]:\//;
 
 function parseUrl(sourceUrl) {
-  const url = __non_webpack_require__("url");
+  const { url } = globalThis.__pdfjsPackages__;
   const parsedUrl = url.parse(sourceUrl);
   if (parsedUrl.protocol === "file:" || parsedUrl.host) {
     return parsedUrl;
@@ -340,13 +339,13 @@ class PDFNodeStreamFullReader extends BaseFullReader {
 
     this._request = null;
     if (this._url.protocol === "http:") {
-      const http = __non_webpack_require__("http");
+      const { http } = globalThis.__pdfjsPackages__;
       this._request = http.request(
         createRequestOptions(this._url, stream.httpHeaders),
         handleResponse
       );
     } else {
-      const https = __non_webpack_require__("https");
+      const { https } = globalThis.__pdfjsPackages__;
       this._request = https.request(
         createRequestOptions(this._url, stream.httpHeaders),
         handleResponse
@@ -389,13 +388,13 @@ class PDFNodeStreamRangeReader extends BaseRangeReader {
 
     this._request = null;
     if (this._url.protocol === "http:") {
-      const http = __non_webpack_require__("http");
+      const { http } = globalThis.__pdfjsPackages__;
       this._request = http.request(
         createRequestOptions(this._url, this._httpHeaders),
         handleResponse
       );
     } else {
-      const https = __non_webpack_require__("https");
+      const { https } = globalThis.__pdfjsPackages__;
       this._request = https.request(
         createRequestOptions(this._url, this._httpHeaders),
         handleResponse
@@ -420,7 +419,7 @@ class PDFNodeStreamFsFullReader extends BaseFullReader {
       path = path.replace(/^\//, "");
     }
 
-    const fs = __non_webpack_require__("fs");
+    const { fs } = globalThis.__pdfjsPackages__;
     fs.lstat(path, (error, stat) => {
       if (error) {
         if (error.code === "ENOENT") {
@@ -450,7 +449,7 @@ class PDFNodeStreamFsRangeReader extends BaseRangeReader {
       path = path.replace(/^\//, "");
     }
 
-    const fs = __non_webpack_require__("fs");
+    const { fs } = globalThis.__pdfjsPackages__;
     this._setReadableStream(fs.createReadStream(path, { start, end: end - 1 }));
   }
 }
diff --git a/src/display/node_utils.js b/src/display/node_utils.js
index 3dd584212d536..07abc6cd2242c 100644
--- a/src/display/node_utils.js
+++ b/src/display/node_utils.js
@@ -12,7 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* globals __non_webpack_require__ */
+/* globals __non_webpack_import__, __non_webpack_require__ */
 
 import {
   BaseCanvasFactory,
@@ -28,15 +28,59 @@ if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
   );
 }
 
+if (isNodeJS && !globalThis.__pdfjsPackages__) {
+  let fs, http, https, url, canvas, path2d_polyfill;
+
+  if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("LIB")) {
+    // Native packages.
+    fs = __non_webpack_require__("fs");
+    http = __non_webpack_require__("http");
+    https = __non_webpack_require__("https");
+    url = __non_webpack_require__("url");
+    // Optional, third-party, packages.
+    try {
+      canvas = __non_webpack_require__("canvas");
+    } catch {}
+    try {
+      path2d_polyfill = __non_webpack_require__("path2d-polyfill");
+    } catch {}
+  } else {
+    // Native packages.
+    fs = await __non_webpack_import__("fs");
+    http = await __non_webpack_import__("http");
+    https = await __non_webpack_import__("https");
+    url = await __non_webpack_import__("url");
+    // Optional, third-party, packages.
+    try {
+      canvas = await __non_webpack_import__("canvas");
+    } catch {}
+    try {
+      path2d_polyfill = await __non_webpack_import__("path2d-polyfill");
+    } catch {}
+  }
+  globalThis.__pdfjsPackages__ = {
+    CanvasRenderingContext2D: canvas?.CanvasRenderingContext2D,
+    createCanvas: canvas?.createCanvas,
+    DOMMatrix: canvas?.DOMMatrix,
+    fs,
+    http,
+    https,
+    polyfillPath2D: path2d_polyfill?.polyfillPath2D,
+    url,
+  };
+}
+
 if (typeof PDFJSDev !== "undefined" && !PDFJSDev.test("SKIP_BABEL")) {
   (function checkDOMMatrix() {
     if (globalThis.DOMMatrix || !isNodeJS) {
       return;
     }
-    try {
-      globalThis.DOMMatrix = __non_webpack_require__("canvas").DOMMatrix;
-    } catch (ex) {
-      warn(`Cannot polyfill \`DOMMatrix\`, rendering may be broken: "${ex}".`);
+    const { DOMMatrix } = globalThis.__pdfjsPackages__;
+
+    if (DOMMatrix) {
+      globalThis.DOMMatrix = DOMMatrix;
+    } else {
+      warn("Cannot polyfill `DOMMatrix`, rendering may be broken.");
     }
   })();
 
@@ -44,21 +88,21 @@ if (typeof PDFJSDev !== "undefined" && !PDFJSDev.test("SKIP_BABEL")) {
     if (globalThis.Path2D || !isNodeJS) {
       return;
     }
-    try {
-      const { CanvasRenderingContext2D } = __non_webpack_require__("canvas");
-      const { polyfillPath2D } = __non_webpack_require__("path2d-polyfill");
+    const { CanvasRenderingContext2D, polyfillPath2D } =
+      globalThis.__pdfjsPackages__;
 
+    if (CanvasRenderingContext2D && polyfillPath2D) {
       globalThis.CanvasRenderingContext2D = CanvasRenderingContext2D;
       polyfillPath2D(globalThis);
-    } catch (ex) {
-      warn(`Cannot polyfill \`Path2D\`, rendering may be broken: "${ex}".`);
+    } else {
+      warn("Cannot polyfill `Path2D`, rendering may be broken.");
     }
   })();
 }
 
 const fetchData = function (url) {
   return new Promise((resolve, reject) => {
-    const fs = __non_webpack_require__("fs");
+    const { fs } = globalThis.__pdfjsPackages__;
     fs.readFile(url, (error, data) => {
       if (error || !data) {
         reject(new Error(error));
@@ -76,8 +120,8 @@ class NodeCanvasFactory extends BaseCanvasFactory {
    * @ignore
    */
   _createCanvas(width, height) {
-    const Canvas = __non_webpack_require__("canvas");
-    return Canvas.createCanvas(width, height);
+    const { createCanvas } = globalThis.__pdfjsPackages__;
+    return createCanvas(width, height);
   }
 }
 
diff --git a/src/pdf.js b/src/pdf.js
index 16f18a3c10d96..cc8d6af5872a2 100644
--- a/src/pdf.js
+++ b/src/pdf.js
@@ -59,7 +59,6 @@ import {
   getXfaPageViewport,
   isDataScheme,
   isPdfFile,
-  loadScript,
   noContextMenu,
   PDFDateString,
   PixelsPerInch,
@@ -102,7 +101,6 @@ export {
   InvalidPDFException,
   isDataScheme,
   isPdfFile,
-  loadScript,
   MissingPDFException,
   noContextMenu,
   normalizeUnicode,
diff --git a/src/pdf.worker.entry.js b/src/pdf.worker.entry.js
index b7c48218c88df..696c108193dc6 100644
--- a/src/pdf.worker.entry.js
+++ b/src/pdf.worker.entry.js
@@ -16,4 +16,4 @@
 (typeof window !== "undefined"
   ? window
   : {}
-).pdfjsWorker = require("./pdf.worker.js");
+).pdfjsWorker = require("./pdf.worker.mjs");
diff --git a/test/driver.js b/test/driver.js
index 6ec0e5a4f815d..406a31efdc839 100644
--- a/test/driver.js
+++ b/test/driver.js
@@ -34,7 +34,7 @@ const STANDARD_FONT_DATA_URL = "/build/generic/web/standard_fonts/";
 const IMAGE_RESOURCES_PATH = "/web/images/";
 const VIEWER_CSS = "../build/components/pdf_viewer.css";
 const VIEWER_LOCALE = "en-US";
-const WORKER_SRC = "../build/generic/build/pdf.worker.js";
+const WORKER_SRC = "../build/generic/build/pdf.worker.mjs";
 const RENDER_TASK_ON_CONTINUE_DELAY = 5; // ms
 const SVG_NS = "http://www.w3.org/2000/svg";
 
diff --git a/test/test_slave.html b/test/test_slave.html
index b8913f86264ab..1e45c9ede121d 100644
--- a/test/test_slave.html
+++ b/test/test_slave.html
@@ -18,8 +18,8 @@
   <head>
     <title>PDF.js test slave</title>
     <meta charset="utf-8">
-    <script src="../build/generic/build/pdf.js"></script>
-    <script src="../build/components/pdf_viewer.js"></script>
+    <script src="../build/generic/build/pdf.mjs" type="module"></script>
+    <script src="../build/components/pdf_viewer.mjs" type="module"></script>
 
     <link rel="resource" type="application/l10n" href="../build/generic/web/locale/locale.properties">
   </head>
diff --git a/test/unit/api_spec.js b/test/unit/api_spec.js
index f569a6dd2dde9..0396325c080b3 100644
--- a/test/unit/api_spec.js
+++ b/test/unit/api_spec.js
@@ -56,6 +56,8 @@ import { GlobalImageCache } from "../../src/core/image_utils.js";
 import { GlobalWorkerOptions } from "../../src/display/worker_options.js";
 import { Metadata } from "../../src/display/metadata.js";
 
+const WORKER_SRC = "../../build/generic/build/pdf.worker.mjs";
+
 describe("api", function () {
   const basicApiFileName = "basicapi.pdf";
   const basicApiFileLength = 105779; // bytes
@@ -914,7 +916,8 @@ describe("api", function () {
       }
 
       GlobalWorkerOptions.workerPort = new Worker(
-        new URL("../../build/generic/build/pdf.worker.js", window.location)
+        new URL(WORKER_SRC, window.location),
+        { type: "module" }
       );
 
       const loadingTask1 = getDocument(basicApiGetDocumentParams);
@@ -934,7 +937,8 @@ describe("api", function () {
       }
 
       GlobalWorkerOptions.workerPort = new Worker(
-        new URL("../../build/generic/build/pdf.worker.js", window.location)
+        new URL(WORKER_SRC, window.location),
+        { type: "module" }
       );
 
       const loadingTask1 = getDocument(basicApiGetDocumentParams);
@@ -963,7 +967,8 @@ describe("api", function () {
         }
 
         GlobalWorkerOptions.workerPort = new Worker(
-          new URL("../../build/generic/build/pdf.worker.js", window.location)
+          new URL(WORKER_SRC, window.location),
+          { type: "module" }
         );
 
         const loadingTask = getDocument(basicApiGetDocumentParams);
diff --git a/test/unit/jasmine-boot.js b/test/unit/jasmine-boot.js
index 96d48558de55c..5852ae6daa8f6 100644
--- a/test/unit/jasmine-boot.js
+++ b/test/unit/jasmine-boot.js
@@ -108,7 +108,7 @@ async function initializePDFJS(callback) {
     );
   }
   // Configure the worker.
-  GlobalWorkerOptions.workerSrc = "../../build/generic/build/pdf.worker.js";
+  GlobalWorkerOptions.workerSrc = "../../build/generic/build/pdf.worker.mjs";
 
   callback();
 }
diff --git a/test/unit/pdf_spec.js b/test/unit/pdf_spec.js
index 413b9708dd45a..d647f5ced7313 100644
--- a/test/unit/pdf_spec.js
+++ b/test/unit/pdf_spec.js
@@ -49,7 +49,6 @@ import {
   getXfaPageViewport,
   isDataScheme,
   isPdfFile,
-  loadScript,
   noContextMenu,
   PDFDateString,
   PixelsPerInch,
@@ -88,7 +87,6 @@ const expectedAPI = Object.freeze({
   InvalidPDFException,
   isDataScheme,
   isPdfFile,
-  loadScript,
   MissingPDFException,
   noContextMenu,
   normalizeUnicode,
@@ -132,10 +130,9 @@ describe("web_pdfjsLib", function () {
     if (isNodeJS) {
       pending("loadScript is not supported in Node.js.");
     }
-    await loadScript(
-      "../../build/generic/build/pdf.js",
-      /* removeScriptElement = */ true
-    );
+    const apiPath = "../../build/generic/build/pdf.mjs";
+    await import(apiPath);
+
     const webPdfjsLib = await import("../../web/pdfjs.js");
 
     expect(Object.keys(webPdfjsLib).sort()).toEqual(
diff --git a/test/unit/scripting_spec.js b/test/unit/scripting_spec.js
index bfcc10a567a84..dbeb58d9b8f9d 100644
--- a/test/unit/scripting_spec.js
+++ b/test/unit/scripting_spec.js
@@ -13,9 +13,7 @@
  * limitations under the License.
  */
 
-import { loadScript } from "../../src/display/display_utils.js";
-
-const sandboxBundleSrc = "../../build/generic/build/pdf.sandbox.js";
+const sandboxBundleSrc = "../../build/generic/build/pdf.sandbox.mjs";
 
 describe("Scripting", function () {
   let sandbox, send_queue, test_id, ref, windowAlert;
@@ -53,8 +51,9 @@ describe("Scripting", function () {
       const command = "alert";
       send_queue.set(command, { command, value });
     };
-    const promise = loadScript(sandboxBundleSrc).then(() => {
-      return window.pdfjsSandbox.QuickJSSandbox();
+    // eslint-disable-next-line no-unsanitized/method
+    const promise = import(sandboxBundleSrc).then(pdfjsSandbox => {
+      return pdfjsSandbox.QuickJSSandbox();
     });
     sandbox = {
       createSandbox(data) {
diff --git a/web/app.js b/web/app.js
index 560fb784b705a..d5675e5785281 100644
--- a/web/app.js
+++ b/web/app.js
@@ -44,7 +44,6 @@ import {
   InvalidPDFException,
   isDataScheme,
   isPdfFile,
-  loadScript,
   MissingPDFException,
   PDFWorker,
   PromiseCapability,
@@ -2264,10 +2263,10 @@ async function loadFakeWorker() {
   GlobalWorkerOptions.workerSrc ||= AppOptions.get("workerSrc");
 
   if (typeof PDFJSDev === "undefined") {
-    window.pdfjsWorker = await import("pdfjs/pdf.worker.js");
+    globalThis.pdfjsWorker = await import("pdfjs/pdf.worker.js");
     return;
   }
-  await loadScript(PDFWorker.workerSrc);
+  await __non_webpack_import__(PDFWorker.workerSrc); // eslint-disable-line no-undef
 }
 
 async function loadPDFBug(self) {
diff --git a/web/app_options.js b/web/app_options.js
index 13de9889854cf..e461f3910e85e 100644
--- a/web/app_options.js
+++ b/web/app_options.js
@@ -300,8 +300,8 @@ const defaultOptions = {
       typeof PDFJSDev === "undefined"
         ? "../src/pdf.worker.js"
         : PDFJSDev.test("MOZCENTRAL")
-        ? "resource://pdf.js/build/pdf.worker.js"
-        : "../build/pdf.worker.js",
+        ? "resource://pdf.js/build/pdf.worker.mjs"
+        : "../build/pdf.worker.mjs",
     kind: OptionKind.WORKER,
   },
 };
@@ -325,8 +325,8 @@ if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
     /** @type {string} */
     value:
       typeof PDFJSDev === "undefined"
-        ? "../build/dev-sandbox/pdf.sandbox.js"
-        : "../build/pdf.sandbox.js",
+        ? "../build/dev-sandbox/pdf.sandbox.mjs"
+        : "../build/pdf.sandbox.mjs",
     kind: OptionKind.VIEWER,
   };
 } else if (PDFJSDev.test("CHROME")) {
diff --git a/web/generic_scripting.js b/web/generic_scripting.js
index 0c0aa8024df78..8b7f33305c1cb 100644
--- a/web/generic_scripting.js
+++ b/web/generic_scripting.js
@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
-import { getPdfFilenameFromUrl, loadScript } from "pdfjs-lib";
+import { getPdfFilenameFromUrl } from "pdfjs-lib";
 
 async function docProperties(pdfDocument) {
   const url = "",
@@ -41,11 +41,16 @@ async function docProperties(pdfDocument) {
 
 class GenericScripting {
   constructor(sandboxBundleSrc) {
-    this._ready = loadScript(
-      sandboxBundleSrc,
-      /* removeScriptElement = */ true
-    ).then(() => {
-      return window.pdfjsSandbox.QuickJSSandbox();
+    this._ready = new Promise((resolve, reject) => {
+      const sandbox =
+        typeof PDFJSDev === "undefined"
+          ? import(sandboxBundleSrc) // eslint-disable-line no-unsanitized/method
+          : __non_webpack_import__(sandboxBundleSrc); // eslint-disable-line no-undef
+      sandbox
+        .then(pdfjsSandbox => {
+          resolve(pdfjsSandbox.QuickJSSandbox());
+        })
+        .catch(reject);
     });
   }
 
diff --git a/web/pdfjs.js b/web/pdfjs.js
index cb9f39d74d4fb..3ca9b549072f7 100644
--- a/web/pdfjs.js
+++ b/web/pdfjs.js
@@ -35,7 +35,6 @@ const {
   InvalidPDFException,
   isDataScheme,
   isPdfFile,
-  loadScript,
   MissingPDFException,
   noContextMenu,
   normalizeUnicode,
@@ -81,7 +80,6 @@ export {
   InvalidPDFException,
   isDataScheme,
   isPdfFile,
-  loadScript,
   MissingPDFException,
   noContextMenu,
   normalizeUnicode,
diff --git a/web/viewer-geckoview.html b/web/viewer-geckoview.html
index 6f42a2f560293..b6ebd15d61588 100644
--- a/web/viewer-geckoview.html
+++ b/web/viewer-geckoview.html
@@ -76,7 +76,7 @@
 
     <script src="viewer-geckoview.js" type="module-shim"></script>
 <!--#else-->
-<!--<script src="resource://pdf.js/web/viewer.js"></script>-->
+<!--<script src="resource://pdf.js/web/viewer.mjs" type="module"></script>-->
 <!--#endif-->
 
   </head>
diff --git a/web/viewer-snippet-chrome-extension.html b/web/viewer-snippet-chrome-extension.html
index dcf2ed59800c3..6cd81812e09a8 100644
--- a/web/viewer-snippet-chrome-extension.html
+++ b/web/viewer-snippet-chrome-extension.html
@@ -1,4 +1,4 @@
 <!-- This snippet is used in the Chromium extension (included from viewer.html) -->
 <base href="/content/web/">
 <link rel="resource" type="application/l10n" href="locale/locale.properties">
-<script src="../build/pdf.js"></script>
+<script src="../build/pdf.mjs" type="module"></script>
diff --git a/web/viewer-snippet-firefox-extension.html b/web/viewer-snippet-firefox-extension.html
index c7c416d503b57..aa6cf5d9b10a9 100644
--- a/web/viewer-snippet-firefox-extension.html
+++ b/web/viewer-snippet-firefox-extension.html
@@ -1,2 +1,2 @@
 <!-- This snippet is used in the Firefox extension (included from viewer.html) -->
-<script src="resource://pdf.js/build/pdf.js"></script>
+<script src="resource://pdf.js/build/pdf.mjs" type="module"></script>
diff --git a/web/viewer-snippet.html b/web/viewer-snippet.html
index f0bea7080a8eb..56864bf6769fa 100644
--- a/web/viewer-snippet.html
+++ b/web/viewer-snippet.html
@@ -1,3 +1,3 @@
 <!-- This snippet is used in production (included from viewer.html) -->
 <link rel="resource" type="application/l10n" href="locale/locale.properties">
-<script src="../build/pdf.js"></script>
+<script src="../build/pdf.mjs" type="module"></script>
diff --git a/web/viewer.html b/web/viewer.html
index 95382b72704e9..0b0d9d1527365 100644
--- a/web/viewer.html
+++ b/web/viewer.html
@@ -44,9 +44,9 @@
 <!--#endif-->
 
 <!--#if MOZCENTRAL-->
-<!--<script src="resource://pdf.js/web/viewer.js"></script>-->
+<!--<script src="resource://pdf.js/web/viewer.mjs" type="module"></script>-->
 <!--#elif !MOZCENTRAL-->
-<!--<script src="viewer.js"></script>-->
+<!--<script src="viewer.mjs" type="module"></script>-->
 <!--#elif /* Development mode. */-->
     <link rel="resource" type="application/l10n" href="locale/locale.properties">