Hey everyone Christian here,
Recently I stumbled upon a Wiki project to do for someone:
Project: http://community.invisionpower.com/resources/projects/_/ipb-and-mediawiki-bridgesingle-sign-on-r81
This project was a sing-sign on bridge. This was already implemented, but for older versions of IPB. I used to be on the project last year but I left it, because I had work so I couldn't contribute to it fully. I had old logs set for it for fixes but never really got to finish all of it as I was busy as stated earlier.
So when I decided to do it I wanted it to work for the latest version of IPB, because that what I use.
Originally the IPBWiki interface worked up to 3.1.x I believe. So I modified it a bit and did some remodeling in the AdminCP so the structure would fit it. Currently there are a few noticeable bugs in the AdminCP (not bugs, rather Skin issues), but I'll fix that in the later versions. Right now I want to fully get back into Mediawiki again and check it out.
For a demo of the IPBWiki head here: http://demo.animehaven.net/ipb/
TODO List:
Ask users for features they need 
(I still need to brush up on my coding skills but ill do my best)
Integrate IPB's default theme with it. (currently uses some other themes and it's default theme.)
Fix some AdminCP skin issues.
Language Packs ( Right now its a bit dusty, but im trying to learn how to implement languages in it so give me time)
Remove dependencies for older versions of IPB as I will not support them.
If you are planning on giving it a go for yourself:
Mediawiki 1.20.x+ requires PHP 5.3 as the minimum
Mediawiki 1.9.x requires PHP 5.2 as the minimum
Features of IPBWiki:
Seamless integration of the login system of MediaWiki and Invision Power Board. Your website visitors get the convenience of a single sign-on into the forum and the wiki, leading to an increased community participation. IpbWiki provides 2 authentication methods:
Transparent User Authentication: if the user visited the forum and there exists a forum session, then user is automatically logged in into the wiki.
Non-transparent User Authentication: Clicking the Login button in the wiki authenticates against the forum database and logs the user in both the wiki and (optionally) the forum.
Integrated Skins: Out of the box skin integration.
Configure Wiki-Rights: grant wiki-rights (read, edit, minoredit, createpage, createtalk, move, delete, undelete, protect, block, createaccount, upload, reupload, reupload-shared, rollback, patrol, editinterface, siteadmin, bot, asksql, checkuser) based on the member's Forum User Group and member's number of posts.
Supports BBCode & Emotions: IpbWiki Parses BBCode so your forum members continue to use the familiar forum BBCode, leading to an increased community participation. Emoticons are also supported.
Automatically link keywords in your forum post to wiki-topics by using the Automatic wikification extension, or link to topics manually by using the [wiki] bbcode
Discussion Threads: possibility to configure IpbWiki to redirect the wiki discussion tabpage to a forum discussion thread, again leading to an increased community participation.
Rating System: Allows your visitors to provide feedback how much they like your articles.
Limited CMS capabilities: Add topiclists and forum posts inside your wiki pages.
Online Users Integration: Show in 1 list who's active on your forum and wiki.
Poweful & Convenient Control Panel: All options can be simply selected turned on/off in your Admin CP Panel.
Link multiple wikis to 1 forum
Since IpbWiki is based on MediaWiki you can automatically enjoy all features of MediaWiki when you use IpbWiki
No Programming Or Editing Needed: Simple installation and a user friendly control panel supports configuring features as you need.
I will be applying updates and patches when needed, when I have the time to add them. Since I am still in "School" I wont be on as much when September-June hits.
The integration is free since Mediawiki and open source. I will try to get this into IPB 4.0 when it releases, but it wont be immediate (hopefully not a lot changes)
Click here to download this file