This site is an attempt to make Drupal work more like a wiki. Some of this is done by adding modules which add wiki-like functions (like using double brackets to add a New Link), but a bit of the design is philosophical as well. I'll admit that some cues were taken from one of the best wikis out there--PBWiki.
The site was taken offline in 2010 because of a failed update and because it was only current for Drupal 5. I've recreated most of the text from cached copies and an important screenshot appears below. Hopefully the general ideas will help someone.
First and foremost, a taxomomy is added to create folders. Wikis traditionally are created and structured like websites where pages are created and interlinked. This is foreign to most who have not created a website, yet the idea of folders makes sense because that's how we organize documents in our operating system. It also takes care of the orphan page problem.
Another philosophical change is limiting the page to one "post" at a time, unless it is a search or tag/folder view. Drupal makes a great blogging platform because it can handle timed posts in so many ways, but a wiki works more on a single page basis. One page, one empty edit box.
Take a look at outline designer for easier organization/allow user creation of folders
Link to content (appears to be dead
Multiauthor issues/views
Update notifications/RSS
Better theming
Look at personal wiki pages
Export from mediawiki, and use feedapi & feed api mapper for import
Editors like TinyMCE don't do well with code pasted from Microsoft Word. There are a number of ways to clean things up, but I've had good luck with a project/module called html Purifier. Essentially, it allows you to set which html tags will be allowed in your pages (users will get an error when using unauthorized tags). Here's my list of allowed tags:
a[href],em,i,b,u,strong,cite,code,ul,ol,li,dl,dt,dd,a,p,h1,h2,h3,h4,h5,h6,hr,br,dl,dt,dd,table,tr,td,blockquote,pre,embed,object,span[text-decoration|text-align]
...and forbidden attributes
span@style,p@style
<?php if (arg(0) == 'node' && is_numeric(arg(1))) $nodeid = arg(1); ?>
<table width="100%" border="0" id="addedit"> <tr> <td><h2><a href="/druwiki/?q=node/add/page">Create new page</a> </h2></td> </tr> <tr> <td><h2><a href="/druwiki/?q=node/<?php print($nodeid)?>/edit">Edit this page</a></h2></td> </tr> </table>
Screenshot of the folder list: