Symfony is a free PHP web application framework for MVC applications.
Ranked in these QuestionsQuestion Ranking
Pro Open Source
Symfony is open source and released under the MIT license.
Pro Great plugin ecosystem
One of the greatest strengths of Symfony is it's amazing and large plugin ecosystem, which comes as a result of it's large and dedicated community. Having a large number of plugins means less development time and more productivity.
Pro Powerful event system
Symfony has a powerful built-in event system that allows you to add flexibility to applications and makes it easier to maintain the codebase down the road.
Pro Easy debugging with a built-in debug toolbar
Symfony comes with a built-in toolbar that helps developers debug their applications during the development phase.
The toolbar is also extendable and new components, called panels can be added if needed to help with the debugging process.
Pro Highly active community
Symfony has one of the most active communities out of all the PHP frameworks. This is shown by the high number of commits made every day in the GitHub repo.
Pro Uses Doctrine ORM
Symfony makes use of the Doctrine ORM to add an abstraction layer over the database in order to maintain flexibility without having unnecessary code duplication.
Pro Uses YAML/XML/PHP/Annotation
Symfony makes use of XML, YAML or PHP annotations to create configurations in order to tell Doctrine on how properties of a certain class should be.
Pro Great templating engine
Uses Twig, which is a simple and easy to learn templating language that can also be used as a standalone engine, outside the framework.
Pro Teaches you good practices
Symfony makes you be a better programmer. You have to deal with the latest object-oriented design patterns such as service-oriented architecture, dependency injection, interface abstraction, and so on.
Con Promotes bad development practices
Such as annotations via comments.
Con Very hard to install
Setting it up on webhost without a console is difficult.
Con Doctrine ORM
Symfony Standard Edition, which is the most widely used distribution, comes integrated with Doctrine, the most resource hogging ORM library.
Con Bad documentation
The documentation is poorly written, so learning Symfony can be difficult, especially for beginners.
Con Low performance
Probably the slowest PHP framework out there.
Con Somewhat high overhead
Symfony can add overhead in terms of CPU and RAM usage as demonstrated by many benchmark tests.
Con You need a lot of files to display a single page
For a simple hello world page you need about 5 files.