2. ContractsA set of abstractions extracted out of the Symfony components
4. Options ResolverThe OptionsResolver component is array_replace() on steroids. It allows you to create an options system with required options, defaults, validation (type, value), normalization and more.
5. AssetThe Asset component manages URL generation and versioning of web assets such as CSS stylesheets, JavaScript files and image files.
6. Polyfill Intl IdnThis component provides a partial, native PHP implementation for the Intl extension (IDN features).
8. Browser KitThe BrowserKit component simulates the behavior of a web browser, allowing you to make requests, click on links and submit forms programmatically.
11. PantherA browser testing and web crawling library for PHP and Symfony
12. Expression LanguageThe ExpressionLanguage component provides an engine that can compile and evaluate expressions.
13. FormThe Form component allows you to easily create, process and reuse HTML forms.
14. InflectorInflector converts words between their singular and plural forms (English only).
15. StopwatchThe Stopwatch component provides a way to profile code.
16. Mercure BundleThe MercureBundle allows to easily push updates to web browsers and other HTTP clients in the Symfony full-stack framework, using the Mercure protocol.
18. Property AccessThe PropertyAccess component provides function to read and write from/to an object or array using a simple string notation.
19. Polyfill Intl IcuThis component provides a collection of functions/classes using the symfony/intl package when the Intl extension is not installed.
20. IntlA PHP replacement layer for the C intl extension that also provides access to the localization data of the ICU library.
21. ValidatorThe Validator component provides tools to validate values following the JSR-303 Bean Validation specification.
23. Twig BridgeProvides integration for Twig with various Symfony components.
24. Phpunit BridgeProvides utilities for PHPUnit, especially user deprecation notices management.
25. Twig BundleThe Twig Bundle provides configuration for using Twig in your applications.
27. Security BundleThe security system is one of the most powerful parts of Symfony and can largely be controlled via its configuration.
28. MimeThe MIME component allows manipulating MIME types.
29. SerializerWith the Serializer component it's possible to handle serializing data structures, including object graphs, into array structures or other formats like XML and JSON. It can also handle deserializing XML and JSON back to object graphs.
30. Polyfill Php73This component provides functions unavailable in releases prior to PHP 7.3.
32. Debug BundleThe DebugBundle allows greater integration of the VarDumper component in the Symfony full-stack framework.
34. Webpack EncoreA simple but powerful API for processing & compiling assets built around Webpack
36. Web Profiler BundleThe WebProfilerBundle provides detailed technical information about each request execution and displays it in both the web debug toolbar and the profiler.
40. Property InfoPropertyInfo extracts information about PHP class' properties using metadata of popular sources.
43. Polyfill IconvThis component provides a native PHP implementation of the php.net/iconv functions.
46. Error HandlerThe ErrorHandler component provides tools to manage errors and ease debugging PHP code.
47. Var ExporterThe VarExporter component allows exporting any serializable PHP data structure to plain PHP code. While doing so, it preserves all the semantics associated with the serialization mechanism of PHP (__wakeup, __sleep, Serializable).
48. Polyfill Php56This component provides functions unavailable in releases prior to PHP 5.6.
49. CliRepository for reporting issues related to the Symfony CLI
50. Polyfill Php55This component provides functions unavailable in releases prior to PHP 5.5.