I know, if i’m not wrong, there is some integration available about phpBB and WordPress.
I had integrate the two systems locally time ago for a work i had to do, but it was very long time ago now.
Never more i have take a look to phpBB code, i have in the past also code two modifications for phpBB, one very basic, that was giving possibility to set one icon for categories with admincp control, while the other one modification was very useful, almost on old phpBB versions where the moderation for topics before there publication was not possible. With the mod , on admincp was possible to set what forum was affected by moderation of topics before the publication for unregistered users.
After, unfortunately i have not find out more times to look and code around the phpBB bulletin board except for a modification bridge of phpBB with WordPress.
I like to add to this blog a little forum now, and of course it will be phpBB with an integration/bridge i will code directly here in these days.
phpBB’s files upload have start.