diff --git a/src/Autocomplete/assets/dist/controller.js b/src/Autocomplete/assets/dist/controller.js
index a559b224749..23b4e6515ba 100644
--- a/src/Autocomplete/assets/dist/controller.js
+++ b/src/Autocomplete/assets/dist/controller.js
@@ -1,25 +1,25 @@
 import { Controller } from '@hotwired/stimulus';
 import TomSelect from 'tom-select';
 
-/******************************************************************************
-Copyright (c) Microsoft Corporation.
-
-Permission to use, copy, modify, and/or distribute this software for any
-purpose with or without fee is hereby granted.
-
-THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
-REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
-AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
-INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
-LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
-OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
-PERFORMANCE OF THIS SOFTWARE.
-***************************************************************************** */
-
-function __classPrivateFieldGet(receiver, state, kind, f) {
-    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a getter");
-    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot read private member from an object whose class did not declare it");
-    return kind === "m" ? f : kind === "a" ? f.call(receiver) : f ? f.value : state.get(receiver);
+/******************************************************************************
+Copyright (c) Microsoft Corporation.
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THIS SOFTWARE.
+***************************************************************************** */
+
+function __classPrivateFieldGet(receiver, state, kind, f) {
+    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a getter");
+    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot read private member from an object whose class did not declare it");
+    return kind === "m" ? f : kind === "a" ? f.call(receiver) : f ? f.value : state.get(receiver);
 }
 
 var _instances, _getCommonConfig, _createAutocomplete, _createAutocompleteWithHtmlContents, _createAutocompleteWithRemoteData, _stripTags, _mergeObjects, _createTomSelect, _dispatchEvent;
diff --git a/src/Collection/.gitattributes b/src/Collection/.gitattributes
new file mode 100644
index 00000000000..3868d83c803
--- /dev/null
+++ b/src/Collection/.gitattributes
@@ -0,0 +1,8 @@
+/.gitattributes export-ignore
+/.gitignore export-ignore
+/.symfony.bundle.yaml export-ignore
+/phpunit.xml.dist export-ignore
+/phpstan.neon.dist export-ignore
+/Resources/assets/test export-ignore
+/Resources/assets/jest.config.js export-ignore
+/Tests export-ignore
diff --git a/src/Collection/.gitignore b/src/Collection/.gitignore
new file mode 100644
index 00000000000..859b1aa2473
--- /dev/null
+++ b/src/Collection/.gitignore
@@ -0,0 +1,12 @@
+/.php_cs.cache
+/.php_cs
+/.phpunit.result.cache
+/composer.phar
+/composer.lock
+/phpunit.xml
+/vendor/
+/Tests/app/var
+/Tests/app/public/build/
+node_modules/
+package-lock.json
+yarn.lock
diff --git a/src/Collection/.symfony.bundle.yaml b/src/Collection/.symfony.bundle.yaml
new file mode 100644
index 00000000000..50b8d4a3040
--- /dev/null
+++ b/src/Collection/.symfony.bundle.yaml
@@ -0,0 +1,3 @@
+branches: ["2.x"]
+maintained_branches: ["2.x"]
+doc_dir: "Resources/doc"
diff --git a/src/Collection/CONTRIBUTING.md b/src/Collection/CONTRIBUTING.md
new file mode 100644
index 00000000000..fd849829c72
--- /dev/null
+++ b/src/Collection/CONTRIBUTING.md
@@ -0,0 +1,16 @@
+# Contributing
+
+Install the test app:
+
+    $ composer install
+    $ cd Tests/app
+    $ yarn install
+    $ yarn build
+
+Start the test app:
+
+    $ symfony serve
+
+## Run tests
+
+    $ php vendor/bin/simple-phpunit
diff --git a/src/Collection/CollectionBundle.php b/src/Collection/CollectionBundle.php
new file mode 100644
index 00000000000..a8bee206970
--- /dev/null
+++ b/src/Collection/CollectionBundle.php
@@ -0,0 +1,21 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\UX\Collection;
+
+use Symfony\Component\HttpKernel\Bundle\Bundle;
+
+/**
+ * @author Kévin Dunglas <kevin@dunglas.fr>
+ */
+final class CollectionBundle extends Bundle
+{
+}
diff --git a/src/Collection/LICENSE b/src/Collection/LICENSE
new file mode 100644
index 00000000000..5dcd9af2f97
--- /dev/null
+++ b/src/Collection/LICENSE
@@ -0,0 +1,19 @@
+Copyright (c) 2021 Kévin Dunglas
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is furnished
+to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/src/Collection/README.md b/src/Collection/README.md
new file mode 100644
index 00000000000..35efa7c85f9
--- /dev/null
+++ b/src/Collection/README.md
@@ -0,0 +1,11 @@
+# Symfony UX Collection
+
+**This repository is a READ-ONLY sub-tree split**. See
+https://github.com/symfony/ux to create issues or submit pull requests.
+
+## Resources
+
+-   [Documentation](https://symfony.com/bundles/ux-collection/current/index.html)
+-   [Report issues](https://github.com/symfony/ux/issues) and
+    [send Pull Requests](https://github.com/symfony/ux/pulls)
+    in the [main Symfony UX repository](https://github.com/symfony/ux)
diff --git a/src/Collection/Resources/assets/dist/controller.js b/src/Collection/Resources/assets/dist/controller.js
new file mode 100644
index 00000000000..eecb6252531
--- /dev/null
+++ b/src/Collection/Resources/assets/dist/controller.js
@@ -0,0 +1,87 @@
+import { Controller } from '@hotwired/stimulus';
+
+const DEFAULT_ITEMS_SELECTOR = ':scope > :is(div, fieldset)';
+var ButtonType;
+(function (ButtonType) {
+    ButtonType[ButtonType["Add"] = 0] = "Add";
+    ButtonType[ButtonType["Delete"] = 1] = "Delete";
+})(ButtonType || (ButtonType = {}));
+class default_1 extends Controller {
+    connect() {
+        this.connectCollection(this.element);
+    }
+    connectCollection(parent) {
+        parent.querySelectorAll('[data-prototype]').forEach((el) => {
+            const collectionEl = el;
+            const items = this.getItems(collectionEl);
+            collectionEl.dataset.currentIndex = items.length.toString();
+            this.addAddButton(collectionEl);
+            this.getItems(collectionEl).forEach((itemEl) => this.addDeleteButton(collectionEl, itemEl));
+        });
+    }
+    getItems(collectionElement) {
+        return collectionElement.querySelectorAll(collectionElement.dataset.itemsSelector || DEFAULT_ITEMS_SELECTOR);
+    }
+    createButton(collectionEl, buttonType) {
+        var _a;
+        const attributeName = `${ButtonType[buttonType].toLowerCase()}Button`;
+        const button = (_a = collectionEl.dataset[attributeName]) !== null && _a !== void 0 ? _a : this.element.dataset[attributeName];
+        console.log(button);
+        if ('' === button)
+            return null;
+        if (undefined === button || !('content' in document.createElement('template'))) {
+            const button = document.createElement('button');
+            button.type = 'button';
+            button.textContent = ButtonType[buttonType];
+            return button;
+        }
+        const buttonTemplate = document.getElementById(button);
+        if (!buttonTemplate)
+            throw new Error(`template with ID "${buttonTemplate}" not found`);
+        const fragment = buttonTemplate.content.cloneNode(true);
+        if (1 !== fragment.children.length)
+            throw new Error('template with ID "${buttonTemplateID}" must have exactly one child');
+        return fragment.firstElementChild;
+    }
+    addItem(collectionEl) {
+        const currentIndex = collectionEl.dataset.currentIndex;
+        collectionEl.dataset.currentIndex++;
+        const collectionNamePattern = collectionEl.id.replace(/_/g, '(?:_|\\[|]\\[)');
+        const prototype = collectionEl.dataset.prototype
+            .replace('__name__label__', currentIndex)
+            .replace(new RegExp(`(${collectionNamePattern}(?:_|]\\[))__name__`, 'g'), `$1${currentIndex}`);
+        const fakeEl = document.createElement('div');
+        fakeEl.innerHTML = prototype;
+        const itemEl = fakeEl.firstElementChild;
+        this.connectCollection(itemEl);
+        this.addDeleteButton(collectionEl, itemEl);
+        const items = this.getItems(collectionEl);
+        items.length ? items[items.length - 1].insertAdjacentElement('afterend', itemEl) : collectionEl.prepend(itemEl);
+    }
+    addAddButton(collectionEl) {
+        const addButton = this.createButton(collectionEl, ButtonType.Add);
+        if (!addButton)
+            return;
+        addButton.onclick = (e) => {
+            e.preventDefault();
+            this.addItem(collectionEl);
+        };
+        collectionEl.appendChild(addButton);
+    }
+    addDeleteButton(collectionEl, itemEl) {
+        const deleteButton = this.createButton(collectionEl, ButtonType.Delete);
+        if (!deleteButton)
+            return;
+        deleteButton.onclick = (e) => {
+            e.preventDefault();
+            itemEl.remove();
+        };
+        itemEl.appendChild(deleteButton);
+    }
+}
+default_1.values = {
+    addButton: '',
+    deleteButton: '',
+};
+
+export { default_1 as default };
diff --git a/src/Collection/Resources/assets/jest.config.js b/src/Collection/Resources/assets/jest.config.js
new file mode 100644
index 00000000000..6358ddf2772
--- /dev/null
+++ b/src/Collection/Resources/assets/jest.config.js
@@ -0,0 +1 @@
+module.exports = require('../../../../jest.config.js');
diff --git a/src/Collection/Resources/assets/package.json b/src/Collection/Resources/assets/package.json
new file mode 100644
index 00000000000..d777a69ba74
--- /dev/null
+++ b/src/Collection/Resources/assets/package.json
@@ -0,0 +1,24 @@
+{
+    "name": "@symfony/ux-collection",
+    "description": "Support for collection embedding with Symfony Form",
+    "license": "MIT",
+    "main": "dist/controller.js",
+    "module": "dist/controller.js",
+    "version": "1.0.0",
+    "symfony": {
+        "controllers": {
+            "collection": {
+                "main": "dist/controller.js",
+                "webpackMode": "eager",
+                "fetch": "eager",
+                "enabled": true
+            }
+        }
+    },
+    "peerDependencies": {
+        "@hotwired/stimulus": "^3.0.0"
+    },
+    "devDependencies": {
+        "@hotwired/stimulus": "^3.0.0"
+    }
+}
diff --git a/src/Collection/Resources/assets/src/controller.ts b/src/Collection/Resources/assets/src/controller.ts
new file mode 100644
index 00000000000..b5c3ea8d981
--- /dev/null
+++ b/src/Collection/Resources/assets/src/controller.ts
@@ -0,0 +1,115 @@
+import { Controller } from '@hotwired/stimulus';
+
+const DEFAULT_ITEMS_SELECTOR = ':scope > :is(div, fieldset)';
+
+interface CollectionDataset extends DOMStringMap {
+    prototype: string;
+    currentIndex: string;
+    itemsSelector?: string;
+    addButton?: string;
+    deleteButton?: string;
+}
+
+enum ButtonType {
+    Add,
+    Delete,
+}
+
+export default class extends Controller {
+    static values = {
+        addButton: '',
+        deleteButton: '',
+    };
+
+    connect() {
+        this.connectCollection(this.element as HTMLElement);
+    }
+
+    connectCollection(parent: HTMLElement) {
+        parent.querySelectorAll('[data-prototype]').forEach((el) => {
+            const collectionEl = el as HTMLElement;
+            const items = this.getItems(collectionEl);
+            collectionEl.dataset.currentIndex = items.length.toString();
+
+            this.addAddButton(collectionEl);
+
+            this.getItems(collectionEl).forEach((itemEl) => this.addDeleteButton(collectionEl, itemEl as HTMLElement));
+        });
+    }
+
+    getItems(collectionElement: HTMLElement) {
+        return collectionElement.querySelectorAll(collectionElement.dataset.itemsSelector || DEFAULT_ITEMS_SELECTOR);
+    }
+
+    createButton(collectionEl: HTMLElement, buttonType: ButtonType): HTMLElement | null {
+        const attributeName = `${ButtonType[buttonType].toLowerCase()}Button`;
+        const button = collectionEl.dataset[attributeName] ?? (this.element as HTMLElement).dataset[attributeName];
+        console.log(button);
+
+        // Button explicitly disabled through data attribute
+        if ('' === button) return null;
+
+        // No data attribute provided or <template> not supported: create raw HTML button
+        if (undefined === button || !('content' in document.createElement('template'))) {
+            const button = document.createElement('button') as HTMLButtonElement;
+            button.type = 'button';
+            button.textContent = ButtonType[buttonType];
+
+            return button;
+        }
+
+        // Use the template referenced by the data attribute
+        const buttonTemplate = document.getElementById(button) as HTMLTemplateElement | null;
+        if (!buttonTemplate) throw new Error(`template with ID "${buttonTemplate}" not found`);
+
+        const fragment = buttonTemplate.content.cloneNode(true) as DocumentFragment;
+        if (1 !== fragment.children.length)
+            throw new Error('template with ID "${buttonTemplateID}" must have exactly one child');
+
+        return fragment.firstElementChild as HTMLElement;
+    }
+
+    addItem(collectionEl: HTMLElement) {
+        const currentIndex = (collectionEl.dataset as CollectionDataset).currentIndex;
+        (collectionEl.dataset.currentIndex as unknown as number)++;
+
+        const collectionNamePattern = collectionEl.id.replace(/_/g, '(?:_|\\[|]\\[)');
+
+        const prototype = (collectionEl.dataset.prototype as string) // We're sure that dataset.prototype exists, because of the CSS selector used in connect()
+            .replace('__name__label__', currentIndex)
+            .replace(new RegExp(`(${collectionNamePattern}(?:_|]\\[))__name__`, 'g'), `$1${currentIndex}`);
+
+        const fakeEl = document.createElement('div');
+        fakeEl.innerHTML = prototype;
+        const itemEl = fakeEl.firstElementChild as HTMLElement;
+
+        this.connectCollection(itemEl);
+
+        this.addDeleteButton(collectionEl, itemEl);
+
+        const items = this.getItems(collectionEl);
+        items.length ? items[items.length - 1].insertAdjacentElement('afterend', itemEl) : collectionEl.prepend(itemEl);
+    }
+
+    addAddButton(collectionEl: HTMLElement) {
+        const addButton = this.createButton(collectionEl, ButtonType.Add);
+        if (!addButton) return;
+
+        addButton.onclick = (e) => {
+            e.preventDefault();
+            this.addItem(collectionEl);
+        };
+        collectionEl.appendChild(addButton);
+    }
+
+    addDeleteButton(collectionEl: HTMLElement, itemEl: HTMLElement) {
+        const deleteButton = this.createButton(collectionEl, ButtonType.Delete);
+        if (!deleteButton) return;
+
+        deleteButton.onclick = (e) => {
+            e.preventDefault();
+            itemEl.remove();
+        };
+        itemEl.appendChild(deleteButton);
+    }
+}
diff --git a/src/Collection/Resources/assets/test/controller.test.ts b/src/Collection/Resources/assets/test/controller.test.ts
new file mode 100644
index 00000000000..da9f6ae16ae
--- /dev/null
+++ b/src/Collection/Resources/assets/test/controller.test.ts
@@ -0,0 +1,40 @@
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+'use strict';
+
+import { Application } from '@hotwired/stimulus';
+import { getByTestId } from '@testing-library/dom';
+import { clearDOM, mountDOM } from '@symfony/stimulus-testing';
+import CollectionController from '../src/controller';
+
+const startStimulus = () => {
+    const application = Application.start();
+    application.register('symfony--ux-collection--collection', CollectionController);
+};
+
+/* eslint-disable no-undef */
+describe('CollectionController', () => {
+    let container: any;
+
+    beforeEach(() => {
+        container = mountDOM('<div data-testid="collection" data-controller="symfony--ux-collection--collection"></div>');
+    });
+
+    afterEach(() => {
+        clearDOM();
+    });
+
+    it('connects', async () => {
+        startStimulus();
+
+        // smoke test
+        expect(getByTestId(container, 'collection')).toHaveAttribute('data-controller', 'symfony--ux-collection--collection');
+    });
+});
diff --git a/src/Collection/Tests/app/Entity/Game.php b/src/Collection/Tests/app/Entity/Game.php
new file mode 100644
index 00000000000..16521cad2fd
--- /dev/null
+++ b/src/Collection/Tests/app/Entity/Game.php
@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Entity;
+
+/**
+ * @author Kévin Dunglas <kevin@dunglas.fr>
+ */
+class Game
+{
+    public \DateTimeImmutable $date;
+    /**
+     * @var Team[]
+     */
+    private array $teams = [];
+
+    public function addTeam(Team $team): void
+    {
+        $this->teams[] = $team;
+        $this->teams = array_values($this->teams);
+
+        dump($this->teams);
+    }
+
+    public function removeTeam(Team $team): void
+    {
+        if (false === $i = array_search($team, $this->teams, true)) {
+            return;
+        }
+
+        unset($this->teams[$i]);
+        $this->teams = array_values($this->teams);
+    }
+
+    public function getTeams(): array
+    {
+        return $this->teams;
+    }
+}
diff --git a/src/Collection/Tests/app/Entity/Player.php b/src/Collection/Tests/app/Entity/Player.php
new file mode 100644
index 00000000000..cf390ceae7f
--- /dev/null
+++ b/src/Collection/Tests/app/Entity/Player.php
@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Entity;
+
+/**
+ * @author Kévin Dunglas <kevin@dunglas.fr>
+ */
+class Player
+{
+    public string $firstName;
+    public string $lastName;
+}
diff --git a/src/Collection/Tests/app/Entity/Team.php b/src/Collection/Tests/app/Entity/Team.php
new file mode 100644
index 00000000000..2cc3b67ee83
--- /dev/null
+++ b/src/Collection/Tests/app/Entity/Team.php
@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Entity;
+
+/**
+ * @author Kévin Dunglas <kevin@dunglas.fr>
+ */
+class Team
+{
+    public string $name;
+    /**
+     * @var Player[]
+     */
+    private array $players = [];
+
+    public function addPlayer(Player $player): void
+    {
+        $this->players[] = $player;
+        $this->players = array_values($this->players);
+    }
+
+    public function removePlayer(Player $player): void
+    {
+        if (false === $i = array_search($player, $this->players, true)) {
+            return;
+        }
+
+        unset($this->players[$i]);
+        $this->players = array_values($this->players);
+    }
+
+    public function getPlayers(): array
+    {
+        return $this->players;
+    }
+}
diff --git a/src/Collection/Tests/app/Form/GameType.php b/src/Collection/Tests/app/Form/GameType.php
new file mode 100644
index 00000000000..0ee387e6e3e
--- /dev/null
+++ b/src/Collection/Tests/app/Form/GameType.php
@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Form;
+
+use App\Entity\Game;
+use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\Extension\Core\Type\CollectionType;
+use Symfony\Component\Form\Extension\Core\Type\DateType;
+use Symfony\Component\Form\Extension\Core\Type\SubmitType;
+use Symfony\Component\Form\FormBuilderInterface;
+use Symfony\Component\OptionsResolver\OptionsResolver;
+
+/**
+ * @author Kévin Dunglas <kevin@dunglas.fr>
+ */
+class GameType extends AbstractType
+{
+    public function buildForm(FormBuilderInterface $builder, array $options): void
+    {
+        $builder
+            ->add('date', DateType::class, ['input' => 'datetime_immutable'])
+            ->add('teams', CollectionType::class, [
+                'entry_type' => TeamType::class,
+                'allow_add' => true,
+                'allow_delete' => true,
+            ])
+            ->add('submit', SubmitType::class)
+        ;
+    }
+
+    public function configureOptions(OptionsResolver $resolver): void
+    {
+        $resolver->setDefaults([
+            'data_class' => Game::class,
+        ]);
+    }
+}
diff --git a/src/Collection/Tests/app/Form/PlayerType.php b/src/Collection/Tests/app/Form/PlayerType.php
new file mode 100644
index 00000000000..12cdf8a6b61
--- /dev/null
+++ b/src/Collection/Tests/app/Form/PlayerType.php
@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Form;
+
+use App\Entity\Player;
+use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\FormBuilderInterface;
+use Symfony\Component\OptionsResolver\OptionsResolver;
+
+/**
+ * @author Kévin Dunglas <kevin@dunglas.fr>
+ */
+class PlayerType extends AbstractType
+{
+    public function buildForm(FormBuilderInterface $builder, array $options): void
+    {
+        $builder
+            ->add('firstName')
+            ->add('lastName')
+        ;
+    }
+
+    public function configureOptions(OptionsResolver $resolver): void
+    {
+        $resolver->setDefaults([
+            'data_class' => Player::class,
+        ]);
+    }
+}
diff --git a/src/Collection/Tests/app/Form/TeamType.php b/src/Collection/Tests/app/Form/TeamType.php
new file mode 100644
index 00000000000..2accf5e8d4d
--- /dev/null
+++ b/src/Collection/Tests/app/Form/TeamType.php
@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Form;
+
+use App\Entity\Team;
+use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\Extension\Core\Type\CollectionType;
+use Symfony\Component\Form\FormBuilderInterface;
+use Symfony\Component\OptionsResolver\OptionsResolver;
+
+/**
+ * @author Kévin Dunglas <kevin@dunglas.fr>
+ */
+class TeamType extends AbstractType
+{
+    public function buildForm(FormBuilderInterface $builder, array $options): void
+    {
+        $builder
+            ->add('name', null, ['attr' => ['data-controller' => 'test']])
+            ->add('players', CollectionType::class, [
+                'entry_type' => PlayerType::class,
+                'allow_add' => true,
+                'allow_delete' => true,
+            ])
+        ;
+    }
+
+    public function configureOptions(OptionsResolver $resolver): void
+    {
+        $resolver->setDefaults([
+            'data_class' => Team::class,
+        ]);
+    }
+}
diff --git a/src/Collection/Tests/app/Kernel.php b/src/Collection/Tests/app/Kernel.php
new file mode 100644
index 00000000000..2110e074312
--- /dev/null
+++ b/src/Collection/Tests/app/Kernel.php
@@ -0,0 +1,94 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App;
+
+use App\Form\GameType;
+use Symfony\Bundle\DebugBundle\DebugBundle;
+use Symfony\Bundle\FrameworkBundle\FrameworkBundle;
+use Symfony\Bundle\FrameworkBundle\Kernel\MicroKernelTrait;
+use Symfony\Bundle\TwigBundle\TwigBundle;
+use Symfony\Bundle\WebProfilerBundle\WebProfilerBundle;
+use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
+use Symfony\Component\Form\FormFactoryInterface;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Kernel as BaseKernel;
+use Symfony\Component\Routing\Loader\Configurator\RoutingConfigurator;
+use Symfony\UX\Collection\CollectionBundle;
+use Symfony\WebpackEncoreBundle\WebpackEncoreBundle;
+use Twig\Environment;
+
+/**
+ * @author Kévin Dunglas <kevin@dunglas.fr>
+ */
+class Kernel extends BaseKernel
+{
+    use MicroKernelTrait;
+
+    public function registerBundles(): iterable
+    {
+        yield new FrameworkBundle();
+        yield new TwigBundle();
+        yield new CollectionBundle();
+        yield new WebpackEncoreBundle();
+        yield new WebProfilerBundle();
+        yield new DebugBundle();
+    }
+
+    protected function configureContainer(ContainerConfigurator $container): void
+    {
+        $container->extension('framework', [
+            'secret' => 'ChangeMe',
+            'test' => 'test' === ($_SERVER['APP_ENV'] ?? 'dev'),
+            'router' => [
+                'utf8' => true,
+            ],
+            'profiler' => [
+                'only_exceptions' => false,
+            ],
+        ]);
+
+        $container->extension('webpack_encore', ['output_path' => 'build']);
+        $container->extension('web_profiler', [
+            'toolbar' => true,
+            'intercept_redirects' => false,
+        ]);
+    }
+
+    protected function configureRoutes(RoutingConfigurator $routes): void
+    {
+        $routes->import('@WebProfilerBundle/Resources/config/routing/wdt.xml')->prefix('/_wdt');
+        $routes->import('@WebProfilerBundle/Resources/config/routing/profiler.xml')->prefix('/_profiler');
+
+        $routes->add('form', '/{type<^basic|template$>?basic}')->controller('kernel::form');
+    }
+
+    public function getProjectDir(): string
+    {
+        return __DIR__;
+    }
+
+    public function form(Request $request, Environment $twig, FormFactoryInterface $formFactory, string $type): Response
+    {
+        $form = $formFactory->create(GameType::class);
+
+        $form->handleRequest($request);
+        if ($form->isSubmitted() && $form->isValid()) {
+            // Update array keys
+            $form = $formFactory->create(GameType::class, $form->getData());
+        }
+
+        return new Response(
+            $twig->render("{$type}_form.html.twig", ['form' => $form->createView()])
+        );
+    }
+}
diff --git a/src/Collection/Tests/app/assets/app.js b/src/Collection/Tests/app/assets/app.js
new file mode 100644
index 00000000000..6b4bc1dbe0f
--- /dev/null
+++ b/src/Collection/Tests/app/assets/app.js
@@ -0,0 +1,20 @@
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+import { Application, Controller as BaseController } from "@hotwired/stimulus";
+import Controller from "@symfony/ux-collection/dist/controller.js";
+
+const application = Application.start();
+application.register("symfony--ux-collection--collection", Controller);
+application.register("test", class test extends BaseController {
+    connect() {
+        console.log('Yolo', this.element);
+    }
+});
+console.log('test app initialized');
diff --git a/src/Collection/Tests/app/package.json b/src/Collection/Tests/app/package.json
new file mode 100644
index 00000000000..54ecd45ed84
--- /dev/null
+++ b/src/Collection/Tests/app/package.json
@@ -0,0 +1,22 @@
+{
+    "devDependencies": {
+        "@hotwired/stimulus": "^3.0.0",
+        "@hotwired/turbo": "^7.0.1",
+        "@symfony/ux-collection": "file:../../Resources/assets",
+        "@symfony/webpack-encore": "^0.32.0",
+        "core-js": "^3.0.0",
+        "regenerator-runtime": "^0.13.2",
+        "webpack-notifier": "^1.6.0"
+    },
+    "resolutions": {
+        "coa": "2.0.2"
+    },
+    "license": "MIT",
+    "private": true,
+    "scripts": {
+        "dev-server": "encore dev-server",
+        "dev": "encore dev",
+        "watch": "encore dev --watch",
+        "build": "encore production --progress"
+    }
+}
diff --git a/src/Collection/Tests/app/public/index.php b/src/Collection/Tests/app/public/index.php
new file mode 100644
index 00000000000..3b0f4f6a53c
--- /dev/null
+++ b/src/Collection/Tests/app/public/index.php
@@ -0,0 +1,28 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+use App\Kernel;
+use Symfony\Bundle\FrameworkBundle\Console\Application;
+use Symfony\Component\HttpFoundation\Request;
+
+require __DIR__.'/../../../vendor/autoload.php';
+
+$app = new Kernel($_SERVER['APP_ENV'] ?? 'dev', $_SERVER['APP_DEBUG'] ?? true);
+
+if (\PHP_SAPI === 'cli') {
+    $application = new Application($app);
+    exit($application->run());
+}
+
+$request = Request::createFromGlobals();
+$response = $app->handle($request);
+$response->send();
+$app->terminate($request, $response);
diff --git a/src/Collection/Tests/app/templates/base.html.twig b/src/Collection/Tests/app/templates/base.html.twig
new file mode 100644
index 00000000000..671dad9c562
--- /dev/null
+++ b/src/Collection/Tests/app/templates/base.html.twig
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="UTF-8">
+        <title>Symfony UX Collection</title>
+        {% block stylesheets %}{% endblock %}
+        {{ encore_entry_script_tags('app') }}
+    </head>
+    <body>
+        {% block body %}{% endblock %}
+    </body>
+</html>
diff --git a/src/Collection/Tests/app/templates/basic_form.html.twig b/src/Collection/Tests/app/templates/basic_form.html.twig
new file mode 100644
index 00000000000..138027ac5bd
--- /dev/null
+++ b/src/Collection/Tests/app/templates/basic_form.html.twig
@@ -0,0 +1,9 @@
+{% extends 'base.html.twig' %}
+
+{% block body %}
+    {{ form_start(form, {'attr': {
+        'data-controller': 'symfony--ux-collection--collection'
+    }}) }}
+        {{ form(form) }}
+    {{ form_end(form) }}
+{% endblock %}
diff --git a/src/Collection/Tests/app/templates/template_form.html.twig b/src/Collection/Tests/app/templates/template_form.html.twig
new file mode 100644
index 00000000000..77915538750
--- /dev/null
+++ b/src/Collection/Tests/app/templates/template_form.html.twig
@@ -0,0 +1,37 @@
+{% extends 'base.html.twig' %}
+
+{% block stylesheets %}
+    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.0/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-gH2yIJqKdNHPEq0n4Mqa/HGKIhSkIHeL5AyhkYV8i59U5AR6csBvApHHNl/vI1Bx" crossorigin="anonymous">
+    <style>
+        fieldset {
+            padding: 2em;
+            border: solid;
+        }
+    </style>
+{% block javascripts %}
+    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.2.0/dist/js/bootstrap.bundle.min.js" integrity="sha384-A3rJD856KowSb7dwlZdYEkO39Gagi7vIsF0jrRAoQmDKKtQBHUuLZ9AsSv4jD4Xa" crossorigin="anonymous"></script>{% endblock %}
+{% endblock %}
+
+{% form_theme form 'bootstrap_5_layout.html.twig' %}
+
+{% block body %}
+    <main class="container">
+    <h1>Templated buttons</h1>
+
+    <template id="addButton">
+        <button type="button" class="btn btn-secondary">My add button</button>
+    </template>
+
+    <template id="deleteButton">
+        <button type="button" class="btn btn-danger">My delete button</button>
+    </template>
+
+    {{ form_start(form, {'attr': {
+        'data-controller': 'symfony--ux-collection--collection',
+        'data-add-button': 'addButton',
+        'data-delete-button': 'deleteButton',
+    }}) }}
+        {{ form(form) }}
+    {{ form_end(form) }}
+    </main>
+{% endblock %}
diff --git a/src/Collection/Tests/app/webpack.config.js b/src/Collection/Tests/app/webpack.config.js
new file mode 100644
index 00000000000..aeb1151b30b
--- /dev/null
+++ b/src/Collection/Tests/app/webpack.config.js
@@ -0,0 +1,23 @@
+var Encore = require('@symfony/webpack-encore');
+
+if (!Encore.isRuntimeEnvironmentConfigured()) {
+    Encore.configureRuntimeEnvironment(process.env.NODE_ENV || 'dev');
+}
+
+Encore
+    .setOutputPath('public/build/')
+    .setPublicPath('/build')
+    .addEntry('app', './assets/app.js')
+    .splitEntryChunks()
+    .enableSingleRuntimeChunk()
+    .cleanupOutputBeforeBuild()
+    .enableBuildNotifications()
+    .enableSourceMaps(!Encore.isProduction())
+    .enableVersioning(Encore.isProduction())
+    .configureBabelPresetEnv((config) => {
+        config.useBuiltIns = 'usage';
+        config.corejs = 3;
+    })
+;
+
+module.exports = Encore.getWebpackConfig();
diff --git a/src/Collection/composer.json b/src/Collection/composer.json
new file mode 100644
index 00000000000..3fb68419d45
--- /dev/null
+++ b/src/Collection/composer.json
@@ -0,0 +1,58 @@
+{
+    "name": "symfony/ux-collection",
+    "type": "symfony-bundle",
+    "description": "Support for collection embedding with Symfony Form",
+    "keywords": [
+        "symfony-ux",
+        "form",
+        "collection"
+    ],
+    "homepage": "https://symfony.com",
+    "license": "MIT",
+    "authors": [
+        {
+            "name": "Kévin Dunglas",
+            "email": "kevin@dunglas.fr"
+        },
+        {
+            "name": "Symfony Community",
+            "homepage": "https://symfony.com/contributors"
+        }
+    ],
+    "autoload": {
+        "psr-4": {
+            "Symfony\\UX\\Collection\\": ""
+        },
+        "exclude-from-classmap": [
+            "/Tests/"
+        ]
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "App\\": "Tests/app/"
+        }
+    },
+    "require": {
+        "php": ">=8.1",
+        "symfony/webpack-encore-bundle": "^1.14"
+    },
+    "require-dev": {
+        "symfony/debug-bundle": "^5.4|^6.1",
+        "symfony/form": "^5.4|^6.1",
+        "symfony/framework-bundle": "^5.4|^6.1",
+        "symfony/panther": "^2.0",
+        "symfony/phpunit-bridge": "^5.4|^6.1",
+        "symfony/twig-bundle": "^5.4|^6.1",
+        "symfony/web-profiler-bundle": "^5.4|^6.1"
+    },
+    "conflict": {
+        "symfony/flex": "<1.13"
+    },
+    "extra": {
+        "thanks": {
+            "name": "symfony/ux",
+            "url": "https://github.com/symfony/ux"
+        }
+    },
+    "minimum-stability": "dev"
+}
diff --git a/src/Collection/phpunit.xml.dist b/src/Collection/phpunit.xml.dist
new file mode 100644
index 00000000000..49b9a066d39
--- /dev/null
+++ b/src/Collection/phpunit.xml.dist
@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="vendor/bin/.phpunit/phpunit.xsd"
+         colors="true"
+         bootstrap="vendor/autoload.php"
+         failOnRisky="true"
+         failOnWarning="true"
+>
+    <php>
+        <ini name="error_reporting" value="-1" />
+        <server name="APP_ENV" value="test" force="true" />
+        <server name="APP_DEBUG" value="false" force="true" />
+        <server name="SHELL_VERBOSITY" value="-1" />
+        <server name="KERNEL_CLASS" value="App\Kernel" />
+        <server name="PANTHER_WEB_SERVER_DIR" value="./Tests/app/public" />
+    </php>
+
+    <testsuites>
+        <testsuite name="Project Test Suite">
+            <directory>Tests</directory>
+        </testsuite>
+    </testsuites>
+
+    <filter>
+        <whitelist processUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">src</directory>
+        </whitelist>
+    </filter>
+
+    <listeners>
+        <listener class="Symfony\Bridge\PhpUnit\SymfonyTestsListener" />
+    </listeners>
+
+    <extensions>
+        <extension class="Symfony\Component\Panther\ServerExtension" />
+    </extensions>
+</phpunit>
diff --git a/src/LiveComponent/assets/dist/live_controller.js b/src/LiveComponent/assets/dist/live_controller.js
index d75ccabbe7a..f9c384f7851 100644
--- a/src/LiveComponent/assets/dist/live_controller.js
+++ b/src/LiveComponent/assets/dist/live_controller.js
@@ -1,31 +1,31 @@
 import { Controller } from '@hotwired/stimulus';
 
-/******************************************************************************
-Copyright (c) Microsoft Corporation.
-
-Permission to use, copy, modify, and/or distribute this software for any
-purpose with or without fee is hereby granted.
-
-THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
-REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
-AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
-INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
-LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
-OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
-PERFORMANCE OF THIS SOFTWARE.
-***************************************************************************** */
-
-function __classPrivateFieldGet(receiver, state, kind, f) {
-    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a getter");
-    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot read private member from an object whose class did not declare it");
-    return kind === "m" ? f : kind === "a" ? f.call(receiver) : f ? f.value : state.get(receiver);
-}
-
-function __classPrivateFieldSet(receiver, state, value, kind, f) {
-    if (kind === "m") throw new TypeError("Private method is not writable");
-    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a setter");
-    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot write private member to an object whose class did not declare it");
-    return (kind === "a" ? f.call(receiver, value) : f ? f.value = value : state.set(receiver, value)), value;
+/******************************************************************************
+Copyright (c) Microsoft Corporation.
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THIS SOFTWARE.
+***************************************************************************** */
+
+function __classPrivateFieldGet(receiver, state, kind, f) {
+    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a getter");
+    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot read private member from an object whose class did not declare it");
+    return kind === "m" ? f : kind === "a" ? f.call(receiver) : f ? f.value : state.get(receiver);
+}
+
+function __classPrivateFieldSet(receiver, state, value, kind, f) {
+    if (kind === "m") throw new TypeError("Private method is not writable");
+    if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a setter");
+    if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot write private member to an object whose class did not declare it");
+    return (kind === "a" ? f.call(receiver, value) : f ? f.value = value : state.set(receiver, value)), value;
 }
 
 var DOCUMENT_FRAGMENT_NODE = 11;
@@ -1084,8 +1084,8 @@ function getModelDirectiveFromInput(element, throwOnMissing = true) {
     }
     if (element.getAttribute('name')) {
         const formElement = element.closest('form');
-        if (formElement && formElement.dataset.model) {
-            const directives = parseDirectives(formElement.dataset.model);
+        if (formElement && ('model' in formElement.dataset)) {
+            const directives = parseDirectives(formElement.dataset.model || '*');
             const directive = directives[0];
             if (directive.args.length > 0 || directive.named.length > 0) {
                 throw new Error(`The data-model="${formElement.dataset.model}" format is invalid: it does not support passing arguments to the model.`);
@@ -1222,9 +1222,7 @@ class default_1 extends Controller {
         if (!(this.element instanceof HTMLElement)) {
             throw new Error('Invalid Element Type');
         }
-        if (this.element.dataset.poll !== undefined) {
-            this._initiatePolling(this.element.dataset.poll);
-        }
+        this._initiatePolling();
         window.addEventListener('beforeunload', this.markAsWindowUnloaded);
         this._startAttributesMutationObserver();
         this.element.addEventListener('live:update-model', this.handleUpdateModelEvent);
@@ -1234,9 +1232,7 @@ class default_1 extends Controller {
         this._dispatchEvent('live:connect', { controller: this });
     }
     disconnect() {
-        this.pollingIntervals.forEach((interval) => {
-            clearInterval(interval);
-        });
+        this._stopAllPolling();
         window.removeEventListener('beforeunload', this.markAsWindowUnloaded);
         this.element.removeEventListener('live:update-model', this.handleUpdateModelEvent);
         this.element.removeEventListener('input', this.handleInputEvent);
@@ -1665,7 +1661,12 @@ class default_1 extends Controller {
         }
         this._updateModelFromElement(target, 'change');
     }
-    _initiatePolling(rawPollConfig) {
+    _initiatePolling() {
+        this._stopAllPolling();
+        if (this.element.dataset.poll === undefined) {
+            return;
+        }
+        const rawPollConfig = this.element.dataset.poll;
         const directives = parseDirectives(rawPollConfig || '$render');
         directives.forEach((directive) => {
             let duration = 2000;
@@ -1790,9 +1791,12 @@ class default_1 extends Controller {
         const element = this.element;
         this.mutationObserver = new MutationObserver((mutations) => {
             mutations.forEach((mutation) => {
-                if (mutation.type === 'attributes' && !element.dataset.originalData) {
-                    this.originalDataJSON = this.valueStore.asJson();
-                    this._exposeOriginalData();
+                if (mutation.type === 'attributes') {
+                    if (!element.dataset.originalData) {
+                        this.originalDataJSON = this.valueStore.asJson();
+                        this._exposeOriginalData();
+                    }
+                    this._initiatePolling();
                 }
             });
         });
@@ -1803,6 +1807,11 @@ class default_1 extends Controller {
     getDefaultDebounce() {
         return this.hasDebounceValue ? this.debounceValue : DEFAULT_DEBOUNCE;
     }
+    _stopAllPolling() {
+        this.pollingIntervals.forEach((interval) => {
+            clearInterval(interval);
+        });
+    }
 }
 default_1.values = {
     url: String,