One of the known problems with Drupal is no Wiki module. It is possible to put together a Wiki using various resources but the biggest stumbling block is the text filter.
There have been attempts and some successes. The current perceived wisdom is to use FlexiFilter - sorry but it's just too cumbersome. In fact nightmarish.
And I needed a Wiki filter for a project so this evening I spent 5 hours writing a Wiki filter for Drupal 7.
Does pretty much everything you could want including nested OL/UL lists which can be mixed - I only mention that particularly because it was a bitch. Otherwise it's got italics, bold, underline, strikethrough, h2-h6, blockquotes, code (pre), superscript and subscript.
So to set up a Wiki Text format on Drupal 7 you use these in this order:
- Limit allowed HTML tags - to none, to clear out any tags in the text.
- Then my filter
- Convert line breaks
- Assign IDs to anchors (From the TOC module)
- Table of contents filter module
- Freelinking module to deal with URL links
Then have WikiTools hijack Freelinking (it's an option). And configure the rest as desired.
Voila! A Drupal Wiki.
I will be putting it onto drupal.org presently.