What is this library?
The Symfony PHP framework
Symfony is a set of reusable PHP components, which is the standard foundation on which most PHP applications are built. Choose any of the 50 stand-alone components available for your own applications.
Symfony is also a PHP framework for web projects. With Symfony, you can speed up the creation and maintenance of your PHP web applications. End repetitive coding tasks and enjoy the power of controlling your code.
Symfony is the 5th most starred PHP library on GitHub.