Symfony is a PHP web application framework that was launched in 2005. It is built on the Model-View-Controller (MVC) architecture and offers a wide range of reusable components and libraries. Symfony is known for its scalability, flexibility, and stability.

It offers features like routing, templating, and dependency injection, making it a great choice for building large-scale enterprise applications. Symfony also has a large and active community, which makes it easy to find support and solutions.