Symfony2

Symfony2 is a major rewrite of the PHP framework Symfony, released in 2011. It marked a transition to a more modular, component-based architecture designed to be both a full-stack framework and a library of reusable components. The project aimed to align with modern PHP practices and to improve flexibility, testability, and performance compared with the earlier Symfony 1.x line.

The core of Symfony2 is its dependency injection container and event-driven architecture, which together facilitate decoupled components and easier testing. The framework is structured around bundles—modular units of functionality that can be shared or reused across projects. Routing, form handling, security, templating, and other facilities are provided as separate bundles or components and can be used independently of the full stack. The templating system supported Twig as the recommended engine, while PHP templates were also possible.

Because many elements are implemented as standalone Symfony components, developers could reuse them in other projects without pulling in the whole framework. This component-centric approach contributed to the growth of the Symfony ecosystem and influenced PHP development more broadly, encouraging best practices such as explicit configuration and service-oriented design.

Symfony2 was eventually superseded by later major versions (Symfony3 and beyond). The 2.x line has reached end of life and is not maintained, and new projects are advised to use current releases that include ongoing security updates and improvements.