The implementation of a version management system is a priority to monitor a project and maintain an application.
We use the version manager Git that has become the industry standard. It is used by most open source software (including the Symfony framework itself as well as most of its environment) and is supported by most IDE (including PhpStorm).
The GitHub service is a good addition to the Git version management system. The different formula include a host with deposit backup, management of project contributors, a source code visualisation tool, a ticketing tool, a wiki and statistics. Moreover, GitHub is used by the Symfony community to make open source bundles available.