It was published as free software on October 18, 2005, and released under the MIT License.

Symfony aims to speed up the creation and maintenance of web applications and to replace repetitive coding tasks.

It's also aimed at building robust applications in an enterprise context, and aims to give developers full control over the configuration: from the directory structure to third-party libraries, almost everything can be customized.

[4][5] It makes heavy use of existing PHP open-source projects as part of the framework, including: Symfony also makes use of its own components, which are freely available on the Symfony Components site for various other projects: Symfony is sponsored by SensioLabs, a French software developer and professional services provider.

Later on when it was decided to launch it as open-source framework, the brainstorming resulted in the name symfony (being renamed to Symfony from version 2 and on), which matches the existing theme and class name prefixes.