I have been looking for a way to let my forum-users comment on my posts a long time now, and I am not finding anything that suits what I am looking for. The few I found is a complete bridge, which opens up for other problems.
What I am looking for is a way for my phpBB forum-users to comment on my WordPress-posts, and nothing more. Just like Facebook-comments works, or for example two extra fields when you are posting a comment. One for username and one for password, and when submitted it looks for that user in the phpBB user-table.