Since there seems to be a horrible lack of documentation on how to do this (either it’s a lousy WP plugin to import wiki pages into wp pages [who in their right mind would want to do that?] or its just authentication bridging), I stumbled upon a really easy way to do it:
In your wiki installation, locate load.php inside the includes directory (../path-to-your-wiki/inc). At the top, add this:
Now in your Doku wiki template main.php, add get_header() and get_footer() to grab your wordpress theme header/footer. These should be added right after the opening body tag and right before the closing body tag respectively. For an example:
<body> <?php get_header(); ?> //Doku content <?php get_footer(); ?> </body>
And there you go, you should see your doku wiki load up (hopefully without errors ) with your WP theme’s header/footer. From there you’re kind of on your own with CSS and dealing with style conflicts, etc. In addition to dokuwiki, this site uses FluxBB for its forums, which is a great little lightweight piece of forum software. It’s also a snap to integrate into your wordpress site, and its default theme co-exists with wordpress quite nicely (not a lot of style conflicts). Here’s a visual integration guide from one of the FluxBB authors.
You may also have to modify the WP functions file (our site already had this modification before attempting visual integration), which is described in the DokuWiki-WP auth bridge.
Update: Well, we don’t use FluxBB anymore due to a hardship with linking user accounts. Its still a great piece of software and easy to visually integrate, and I would recommend it.