phpBB can be completely embedded inside Drupal.
phpBB topics can be created from nodes.
phpBB comments instead of Drupal comments.
Can be used on a working site and forum with existing users.
Authentication and synchronization in both directions.
Automatic creation of users.
Synchronization of account info, such as user names, passwords, emails, signatures, and avatars (synchronization is disabled for the Drupal administrator and phpBB administrator for security).
Synchronization of profile information from Profile.
Synchronization of CCK profile fields from Content Profile.
Synchronization of roles and groups.
Support for Drupal forum signatures, avatars, and birthdays.
The forum can be displayed in a full window, in a frame inside Drupal, or in a Drupal page (except for ACP).