CivicActions

For many sites a standard Drupal content type with open permissions and revisions will do enough of the 'wiki-thing' for many situations.

However, there are a bunch of other wiki-like behaviors that you might (on some sites) want to add additional functionality or usability - here is a summary of modules to check out:

• Wikitools (pretty configurable - you don't need to have all of this all the time)
  • Node Creation: Let users create new nodes when they type in a node name which does not exist.
  • Node Search: Let users search for nodes when they type in a node name which does not exist.
  • Automatic Redirect: If a title of a moved page is entered, redirect automatically.
  • Unique Titles: Enforce that titles are unique over all wiki node types
  • Move Protection: Disallow change of node titles for users without administer nodes permission.
  • Delete Protection: Disallow deletion of nodes for users without administer nodes permission.
  • Underscore as Space: Treat underscores as spaces when doing a node-lookup by title.
  • Dash as Space: Treat dashes as spaces when doing a node-lookup by title.
  • Custom wiki 404 pages: pick and choose from links to create, links to search, and an inline node add form.
• Flexifilter (for wikitext or wiki-style templates)
• Textile or pearwiki - other wikitext options
• Freelinking - to automatically create links to the wiki pages for CamelCase or [[bracket links]].
• Tableofcontents - for navigating long pages.
• Talk - put comments on a separate tab.
• Recent Changes - for a sitewide view of diff-able changes.
• Diff - for actually inspecting changes.
• Footnotes - for footnotes/references (duh!).
• Backlinks - good for figuring out and maintaining the structure of the wiki.
• Revision moderation - for control of controversial pages.