phBB is a very popular forum script launched initially in 2000. It is very easy to install because it will detect automatically if your server has all the required components (PHP version, database type etc) and will display an alert if something is wrong. All you nee to do is to have database credentials (name, user and password) and in rest the installation will be very easy, similar with Wordpress.
The administration panel looks clean and simple, but there are many options to manage users and roles, create categories, , add permissions for each group, change security settings and more.
phpBB offers a large number of features to manage the forum, also it has a large community and many plugins are available to install.
The users can manage and edit their profiles, add avatars, use smilies, use private messages and more. You can enhance the functionalities by installing plugins.
phpBB is constantly updated and is important that you keep it updated. The platform has a default option to perform automatically the updates and you should let it turned on.