Orson Teodoro

This plugin is under heavy development. Please do not use it in production unless your willing to accept difficulty of 
upgrading or correctness of the conversion.
ForumConverter migrates post, topics, and users from one forum to a WordPress compatible forum. Currently, 
ForumConverter supports phpBB 3.0.9 to bbPress 2.0 conversion in addition to migrating users as subscribers 
to your WordPress blog.
ForumConverter migrates users from the source forum database to WordPress compatible forum so that migraters can take 
advantage of BuddyPress social networking. This is not a bridge.
For phpBB-to-bbPress conversions, ForumConverter is capable of…
<ul>
<li>reproducing the same forum tree structure for bbPress</li>
<li>reproducing forum post using the same same user, timestamps, sticky flag</li>
<li>allowing converted users to sign on using their existing phpBB password.</li>
<li>converting between BBCode or native bbPress HTML markup</li>
<li>supporting inline attachment conversion and whole topic/reply attachment conversion.</li>
<li>migrating of instant messenger info, global moderator membership, and emails.</li>
<li>password protected forums migration using the same phpBB password</li>
</ul>
Some things that are impossible to do for ForumConverter for phpBB-to-bbPress conversions
<ul>
<li>Complete conversion of custom BBCode. Only YouTube BBCode is supported but BBCode lite does not support YouTube tags. </li>
</ul>
Please read the installation instructions before preceeding. Remote conversion is not supported.

ForumConverter

Migrates a phpBB forum into a bbPress forum.

macmiller

The plugin is intended to create a number of links which you can display on your wordpress page. Each link represents a recent post to the phpBB forum. Clicking on a link will take you to the associated post within that topic on the phpBB forum. There are a number of parameters which indicates how many items should be returned and the length description.
The returned item will look like: 
* <code>POST TITLE(number of replies) in TOPIC TITLE on DATE TIME</code>

phpBB Topics Portal

A widget that accesses your phpBB forum and displays recent posts on your Wordpress page.

ForumConverter vs phpBB Topics Portal