diff --git a/Classes/Controller/IframeMediaChooserController.php b/Classes/Controller/IframeMediaChooserController.php
new file mode 100644
index 000000000..3f110e525
--- /dev/null
+++ b/Classes/Controller/IframeMediaChooserController.php
@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flowpack\Media\Ui\Controller;
+
+/*
+ * This file is part of the Flowpack.Media.Ui package.
+ *
+ * (c) Contributors of the Neos Project - www.neos.io
+ *
+ * This package is Open Source Software. For the full copyright and license
+ * information, please view the LICENSE file which was distributed with this
+ * source code.
+ */
+
+use Neos\Flow\Annotations as Flow;
+use Neos\Fusion\View\FusionView;
+use Neos\Neos\Controller\Module\AbstractModuleController;
+
+/**
+ * This is the entry point for choosing Media by opening an iframe. This is useful for
+ * Flow applications or "traditional" non-React Neos Backend Modules.
+ *
+ * @Flow\Scope("singleton")
+ */
+class IframeMediaChooserController extends AbstractModuleController
+{
+    /**
+     * @var FusionView
+     */
+    protected $view;
+
+    /**
+     * @var string
+     */
+    protected $defaultViewObjectName = FusionView::class;
+
+    /**
+     * @var array
+     */
+    protected $viewFormatToObjectNameMap = [
+        'html' => FusionView::class,
+    ];
+
+    /**
+     * Renders the media chooser
+     */
+    public function indexAction(): void
+    {
+    }
+}
diff --git a/Classes/Eel/MediaChooserNeosConfigHelper.php b/Classes/Eel/MediaChooserNeosConfigHelper.php
new file mode 100644
index 000000000..d9f9b81b5
--- /dev/null
+++ b/Classes/Eel/MediaChooserNeosConfigHelper.php
@@ -0,0 +1,57 @@
+<?php
+declare(strict_types=1);
+
+namespace Flowpack\Media\Ui\Eel;
+
+/*
+ * This file is part of the Flowpack.Media.Ui package.
+ *
+ * (c) Contributors of the Neos Project - www.neos.io
+ *
+ * This package is Open Source Software. For the full copyright and license
+ * information, please view the LICENSE file which was distributed with this
+ * source code.
+ */
+
+use Neos\Flow\Annotations as Flow;
+use Neos\Eel\ProtectedContextAwareInterface;
+use Neos\Neos\Service\UserService;
+use Neos\Neos\Service\XliffService;
+
+/**
+ * This helper is used inside the view rendering of {@see IframeMediaChooserController},
+ * to set up a HTML environment as close as possible to the the Fluid-based backend modules.
+ *
+ * This is a workaround and should NOT be relied upon externally.
+ *
+ * @internal
+ */
+class MediaChooserNeosConfigHelper implements ProtectedContextAwareInterface
+{
+    /**
+     * @Flow\Inject
+     * @var UserService
+     */
+    protected $userService;
+
+    /**
+     * @Flow\Inject
+     * @var XliffService
+     */
+    protected $xliffService;
+
+    public function allowsCallOfMethod($methodName)
+    {
+        return true;
+    }
+
+    public function backendInterfaceLanguage()
+    {
+        return $this->userService->getInterfaceLanguage();
+    }
+
+    public function backendXliffCacheVersion()
+    {
+        return $this->xliffService->getCacheVersion();
+    }
+}
diff --git a/Configuration/Policy.yaml b/Configuration/Policy.yaml
index 278f2c68b..34a7f2e9c 100644
--- a/Configuration/Policy.yaml
+++ b/Configuration/Policy.yaml
@@ -4,6 +4,8 @@ privilegeTargets:
       matcher: 'method(public Flowpack\Media\Ui\Controller\MediaController->(.*)Action())'
     'Flowpack.Media.Ui:Queries':
       matcher: 'method(public Flowpack\Media\Ui\GraphQL\Resolver\(.*)Resolver->.*()) || method(t3n\GraphQL\Controller\GraphQLController->queryAction())'
+    'Flowpack.Media.Ui:IframeMediaChooser':
+      matcher: 'method(public Flowpack\Media\Ui\Controller\IframeMediaChooserController->(.*)Action())'
 
   'Neos\Neos\Security\Authorization\Privilege\ModulePrivilege':
     'Flowpack.Media.Ui:Backend.Module.Management.Media':
diff --git a/Configuration/Routes.yaml b/Configuration/Routes.yaml
index ce99b0e77..c0256ab9b 100644
--- a/Configuration/Routes.yaml
+++ b/Configuration/Routes.yaml
@@ -5,3 +5,10 @@
       package: 't3n.GraphQL'
       variables:
         'endpoint': 'media-assets'
+
+- name: 'IFrame Media Chooser'
+  uriPattern: 'neos/media/asset-choice'
+  defaults:
+    '@package': 'Flowpack.Media.Ui'
+    '@controller': 'IframeMediaChooser'
+    '@action': 'index'
diff --git a/Configuration/Settings.Neos.yaml b/Configuration/Settings.Neos.yaml
index b4b7efa09..07640afff 100644
--- a/Configuration/Settings.Neos.yaml
+++ b/Configuration/Settings.Neos.yaml
@@ -34,3 +34,7 @@ Neos:
         stylesheets:
           Flowpack.Media.Ui:AssetEditor:
             resource: resource://Flowpack.Media.Ui/Public/AssetEditor/Plugin.css
+
+  Fusion:
+    defaultContext:
+      'FlowpackMediaUi.MediaChooserNeosConfig': 'Flowpack\Media\Ui\Eel\MediaChooserNeosConfigHelper'
\ No newline at end of file
diff --git a/Readme.md b/Readme.md
index c04b1a813..91e4bb40d 100644
--- a/Readme.md
+++ b/Readme.md
@@ -88,6 +88,50 @@ Neos:
           showSimilarAssets: true
 ```
     
+### choose assets by rendering media selection iFrame
+
+In Flow applications or "traditional" Neos modules which are not implemented with React, you still sometimes
+need to choose assets. The Media UI provides an extra entry point to allow this. The process works roughly as follows:
+
+1) You open an iFrame, where you display the `IFrameMediaChooser` Controller.
+
+2) The user can pick an image.
+
+3) When the image is chosen, a JavaScript callback function in your outer frame (at location `window.NeosMediaBrowserCallbacks.assetChosen`)
+   is called.
+
+
+**How to set this up in detail?**
+
+1) You need to grant the `Flowpack.Media.Ui:IframeMediaChooser` privilegeTarget if you want to use this feature.
+   Add the following to your `Policy.yaml`, and adjust the role names as you need it for your use-case:
+   
+   ```yaml
+   roles:
+    'Neos.Neos:AbstractEditor':
+      privileges:
+        -
+          privilegeTarget: 'Flowpack.Media.Ui:IframeMediaChooser'
+          permission: GRANT
+   ```
+
+2) Define the callback function `window.NeosMediaBrowserCallbacks.assetChosen(assetId)`:
+
+   ```js
+   window.NeosMediaBrowserCallbacks = {
+       assetChosen: (assetId) => {
+           // do whatever you need to do here
+       }
+   }
+   ```
+
+3) Open the `IFrameMediaChooser` controller in an iframe. To generate the URL to open,
+   you can use the following `UriBuilder` invocation:
+   
+   ```php
+   return $uriBuilder->uriFor('index', [], 'IframeMediaChooser', 'Flowpack.Media.Ui');
+   ```
+
 ## Architecture
 
 ### API / GraphQL
diff --git a/Resources/Private/Fusion/Root.fusion b/Resources/Private/Fusion/Root.fusion
index a92a174cc..febbffaf1 100644
--- a/Resources/Private/Fusion/Root.fusion
+++ b/Resources/Private/Fusion/Root.fusion
@@ -1 +1,2 @@
+include: resource://Neos.Fusion/Private/Fusion/Root.fusion
 include: **/*
diff --git a/Resources/Private/Fusion/Views/IframeMediaChooserController.fusion b/Resources/Private/Fusion/Views/IframeMediaChooserController.fusion
new file mode 100644
index 000000000..525b0746a
--- /dev/null
+++ b/Resources/Private/Fusion/Views/IframeMediaChooserController.fusion
@@ -0,0 +1,42 @@
+// This is the rendering of the stand-alone Iframe Media Selection mode.
+// It emulates the Fluid-based backend layout and calls the Neos JS Bootstrap,
+// so that the Media Selection UI can access e.g. the Neos translations as usual.
+//
+// This whole file is a WORKAROUND and should only be used until we can move some of this
+// into the Neos Core.
+Flowpack.Media.Ui.IframeMediaChooserController {
+    index = Neos.Fusion:Component {
+        mediaModule = Flowpack.Media.Ui:MediaModule
+
+        _neosJavascriptBasePath = ${StaticResource.uri('Neos.Neos', 'Public/JavaScript')}
+        _initScript = ${'<script>window.NeosCMS = {}; window.NeosCMS.Configuration = {}; window.NeosCMS.Configuration.neosJavascriptBasePath = ' + Json.stringify(this._neosJavascriptBasePath) + ';</script>'}
+
+        _xliffAsJsonUri = Neos.Fusion:UriBuilder {
+            package = 'Neos.Neos'
+            controller = 'Backend\\Backend'
+            action = 'xliffAsJson'
+            arguments {
+                locale = ${FlowpackMediaUi.MediaChooserNeosConfig.backendInterfaceLanguage()}
+                version = ${FlowpackMediaUi.MediaChooserNeosConfig.backendXliffCacheVersion()}
+            }
+            absolute = true
+        }
+
+        renderer = afx`
+            <html>
+            <head>
+                <link rel="stylesheet" href={StaticResource.uri('Neos.Neos', 'Public/Styles/Minimal.css')} />
+                <link rel="stylesheet" href={StaticResource.uri('Flowpack.Media.Ui', 'Public/Assets/main.bundle.css')} />
+
+                <link rel="neos-xliff" href={props._xliffAsJsonUri} />
+            </head>
+            <body class="neos neos-module" style="background-color: #222">
+                {props.mediaModule}
+                {props._initScript}
+                <script src={StaticResource.uri('Neos.Neos', 'Public/JavaScript/Main.min.js')}></script>
+                <script src={StaticResource.uri('Flowpack.Media.Ui', 'Public/Assets/main.bundle.js')}></script>
+            </body>
+            </html>
+        `
+    }
+}
diff --git a/Resources/Private/Fusion/Views/Index.fusion b/Resources/Private/Fusion/Views/Index.fusion
index 80a4d2507..d0c2a3f16 100644
--- a/Resources/Private/Fusion/Views/Index.fusion
+++ b/Resources/Private/Fusion/Views/Index.fusion
@@ -1,27 +1,29 @@
-Flowpack.Media.Ui.MediaController {
-    index = Neos.Fusion:Component {
-        data-endpoints = Neos.Fusion:DataStructure {
-            graphql = '/neos/graphql/media-assets'
-            upload = Neos.Fusion:UriBuilder {
-                package = 'Flowpack.Media.Ui'
-                controller = 'Upload'
-                action = 'upload'
-                format = 'json'
-            }
-            @process.stringify = ${Json.stringify(value)}
+prototype(Flowpack.Media.Ui:MediaModule) < prototype(Neos.Fusion:Component) {
+    data-endpoints = Neos.Fusion:DataStructure {
+        graphql = '/neos/graphql/media-assets'
+        upload = Neos.Fusion:UriBuilder {
+            package = 'Flowpack.Media.Ui'
+            controller = 'Upload'
+            action = 'upload'
+            format = 'json'
         }
+        @process.stringify = ${Json.stringify(value)}
+    }
 
-        data-dummy-image = Neos.Fusion:ResourceUri {
-            path = 'resource://Neos.Neos/Public/Images/dummy-image.svg'
-        }
+    data-dummy-image = Neos.Fusion:ResourceUri {
+        path = 'resource://Neos.Neos/Public/Images/dummy-image.svg'
+    }
 
-        data-features = ${Configuration.setting('Neos.Neos.Ui.frontendConfiguration')['Flowpack.Media.Ui']}
-        data-features.@process.stringify = ${Json.stringify(value)}
+    data-features = ${Configuration.setting('Neos.Neos.Ui.frontendConfiguration')['Flowpack.Media.Ui']}
+    data-features.@process.stringify = ${Json.stringify(value)}
 
-        renderer = afx`
-            <div id="media-ui-app" {...props}>
-                Loading media ui...
-            </div>
-        `
-    }
+    renderer = afx`
+        <div id="media-ui-app" {...props}>
+            Loading media ui...
+        </div>
+    `
+}
+
+Flowpack.Media.Ui.MediaController {
+    index = Flowpack.Media.Ui:MediaModule
 }
diff --git a/Resources/Private/JavaScript/media-module/src/index.tsx b/Resources/Private/JavaScript/media-module/src/index.tsx
index f202a2a8d..ff9d96029 100644
--- a/Resources/Private/JavaScript/media-module/src/index.tsx
+++ b/Resources/Private/JavaScript/media-module/src/index.tsx
@@ -79,6 +79,22 @@ window.onload = async (): Promise<void> => {
 
     const AppWithHmr = hot(module)(App);
 
+    // If being called inside an iframe to choose an asset (as described in the section
+    // "choose assets by rendering media selection iFrame" in the main README.md),
+    // we need to set the onAssetSelection callback and set the selectionMode.
+    //
+    // To determine whether we are in this mode or not, we check the following things:
+    // - are we called from within an iframe?
+    // - on the PARENT frame, is window.NeosMediaBrowserCallbacks.assetChosen implemented and callable?
+    let selectionModeProps = {};
+    if (window.parent && window.parent['NeosMediaBrowserCallbacks'] && window.parent['NeosMediaBrowserCallbacks']['assetChosen']) {
+        const NeosMediaBrowserCallbacks = window.parent['NeosMediaBrowserCallbacks'];
+        selectionModeProps = {
+            onAssetSelection: (localAssetIdentifier) => NeosMediaBrowserCallbacks.assetChosen(localAssetIdentifier),
+            selectionMode: true
+        };
+    }
+
     render(
         <IntlProvider translate={translate}>
             <NotifyProvider notificationApi={Notification}>
@@ -89,6 +105,8 @@ window.onload = async (): Promise<void> => {
                                 dummyImage={dummyImage}
                                 containerRef={containerRef}
                                 featureFlags={featureFlags}
+
+                                {...selectionModeProps}
                             >
                                 <MediaUiThemeProvider>
                                     <DndProvider backend={HTML5Backend}>