Sylius is e-commerce solution for PHP, based on the Symfony2 framework.
Sylius is completely open source (MIT license) and free, maintained by diverse and creative community of developers and companies.
If you use a different framework than Symfony, you are welcome to use Sylius components, which will make it much easier to implement a webshop with any PHP application and project. They provide you with default models, services and logic for all aspects of e-commerce, completely separated and ready to use.
composer create-project -s dev sylius/sylius