Symfony 4 was released on November 30th.
Update now to the best Symfony ever!

phpBB

phpBB is a free flat-forum bulletin board software solution that can be used to stay in touch with a group of people or can power your entire website. With an extensive database of user-created modifications and styles database containing hundreds of style and image packages to customise your board, you can create a very unique forum in minutes.

Components used by this project