In Symfony 3.3, the DependencyInjection component has deprecated the possibility of dumping an uncompiled container, the DefinitionDecorator class and the case-insensitivity of service identifiers.
In Symfony 3.3, we added a new Cache adapter for Memcached servers.
In Symfony 3.3, the contents dumped with the "dump()" function include a local search box to help you find any value hidden deep inside complex dumps.
In Symfony 3.3, the "class" argument of the services is now optional. When it's undefined, Symfony considers that the "id" of the service is the PHP class.
Symfony 3.3 adds a new bundle called WebServerBundle to define the local web server related commands.
In Symfony 3.3, cookies include the new "max-age" attribute and they can be created via PHP strings thanks to a new named constructor.
Symfony 3.3 improves the formatting of the JSON and Markdown descriptors for console commands.
In addition to some large new features, Symfony 3.3 will also contain minor tweaks to make your work a bit easier.
In Symfony 3.3, the Configuration panel of the Symfony Profiler will show more information about PHP and Symfony.
In Symfony 3.3, the DomCrawler component added support for the formaction and formmethod attributes that form buttons can define to override the original action and method defined by the form.