onigoetz

This plugin allows to use the password from a working phpBB installation to log into a WordPress blog. or on the other side to log into phpBB with the WordPress user.
The username for the administration must be the same on the two installations. 
Otherwise you will end having admins that have no privileges on the other part.
<h4>How it works</h4>
There is no actual “sync” of the users.
When the app is configured correctly. the app checks that the user who tries to log in is at least registered in one of the systems, if yes, and the password is correct : he’s logged on both systems and his account is created if missing. 
On password change it should also set the password on both platforms.
<h4>WP2BB</h4>
With WP2BB, you can now define that your posts are published in a forum, so that your community can add comments directly on them.
You can add the method “wp2bb()” on your template so that you have links to your forum to add comments and a replies count
There is also a widget to list the last replies in the forums
P.S. : WP2BB was created by Alfredo de Hoces (http://www.alfredodehoces.com/)
<h3>Uninstall</h3>
To uninstall, you have a few steps to make
Go the the Plugin options, revert the “auth mode” to “DB” and not “wpbb” 
If it doesn’t work go to the ACP in General -> Client communication -> Authentication
Then go to the wordpress control panel and disable the plugin.
The last step is then to go with FTP in the PHPBB folder and rename the file “common.php” to “common.wp.php” and the file “common-orig.php” to “common.php”.
Your configurations should be separated again

PHPBB Single Sign On

Authenticate in Wordpress and phpBB at the same time

jhong

Bridge phpBB and WordPress!
WP-United glues together WordPress sites and phpBB forums. Get the full power of WordPress publishing and plugins, with the familiar and established community format of phpBB.
WP-United is fully modular and individual features can be turned on and off. These features include:
<ul>
<li>User integration: including single sign-on, synchronised profiles and avatars, and user management. Works with external registration modules such as social login plugins. Users in phpBB get accounts in WordPress and vice versa. Completely controllable and customisable by setting permissions for who can integrate and at what level, using a unique drag-and-drop interface.</li>
<li>Template integration: Have your phpBB forum appear inside your WordPress site. Or vice-versa; integrate your WordPress blog inside your phpBB header and footer. Includes a “one-click” mode that analyses your theme’s CSS and modifies it on the fly to avoid CSS and HTML conflicts. This is no iFrame solution, it is a complete and automatic template integration.</li>
<li>Behaviour integration: Use phpBB smilies and word censor features in WordPress </li>
<li>Cross-posting: Post something in WordPress and have it cross-posted to your forum — Automatically or manually, you choose! Once an item is cross-posted, comments in phpBB and WordPress can be set to sync up under the blog item too!</li>
</ul>
WP-United also includes TEN widgets for you to drop into your WordPress page. Each widget is configurable and displays a wealth of forum information to increase engagement on your site. All of these widgets work even with the above modules turned off. They are:
<ul>
<li>Latest forum posts</li>
<li>Latest forum topics</li>
<li>users online list</li>
<li>Forum statistics</li>
<li>An integrated login/meta/avatar/profile block</li>
<li>Birthday list</li>
<li>Quick poll (select from active phpBB polls in an ajax widget)</li>
<li>Useful forum links list</li>
<li>Forum top bar (with breadcrumbs that work in WordPress)</li>
<li>Forum bottom bar (to match the top bar!)</li>
</ul>
Visit <a href="http://www.wp-united.com" rel="nofollow ugc">wp-united.com</a> for more information and to view example integrations in the gallery.
The download iincludes the following languages:
<ul>
<li>English</li>
<li>Français</li>
<li>Deutsch</li>
<li>中文（简体）</li>
<li>русский</li>
<li>Srpski (Latinica)</li>
<li>Português Brasileiro</li>
</ul>

PHPBB Single Sign On vs WP-United : phpBB WordPress Integration