Doing a good wiki in Drupal 6 is surprisingly hard. My project to create a site with MediaWiki-like functionality for climate research at UC Berkeley took much longer than I thought it would, and the result was mediocre. Here are my notes evaluating different modules:

Modules I ended up using

• Talk (6.x-1.5)
  • Function: Move the comments into separate tab.
• Configure: Enable in Content Type -> edit -> Workflow settings (which is odd, should be Comment settings).
• Diff (6.x-2.0)
• Function: Show what changed between one revisions.
• Configure: Remember to turn on default revision tracking.
• Limitations: Kind of confusing. Where you go after you are done viewing the diff?
• Pear Wiki Filter (6.x-1.0-beta1)
• Function: Add
• Configure
  • Need to pull Text_Wiki package down from cvs.
  • Need to set path of installed PEAR packages.
• All configuring is hidden on the Input Format configure/configure page. Can be per format.
• Limitations
• No longer supported. Marked as obsoleted in favor of Flexifilter – but flexifilter doesn’t work.
• Does not support —- (hr) or —~~~ (signature).
• Can’t configure it not to not filtering html. I ended up hacking this out of the code.
• Regular expression exceptions don’t seem to work.
• I wasn’t happy with adding new wikilinks and images. I did extensive hacking.
• Wikitools (6.x-1.0)
  • Features: Add a set of wiki behaviors, particularly taking you to the new content page if a link does not exist.
  • Configure: /admin/settings/wikitools. Set to use wikipage.
  • Limitations
    • Move Protection option breaks site.
• Doesn’t mark the links to non-existant pages. I ended up hacking pearwiki to add visual marker.
• Recent Changes (6.x-1.x-dev: 2/36/08)
  • Function: Simple but useful. Create Recent Changes page, with links to revisions and diffs.
• Limitations: I still ended up creating a recent changes view to use as a block.
• Notifications/Messaging
• Function: Very powerful. I used to let interested parties know when a wiki page has been modifed or commented on.
• Limitations: No way to get single-click sign-up.
• BUEditor
• Function: Simple, configurable markup bar. Has buttons to add markup to text area.
• Limitations
  • Only does html out of the box, but easy enough to configure.
• Preview button is great idea, but doesn’t work with wiki syntax.
• Live
  • Function: Show live preview of content textarea.
• Limitations: Needed to submit a patch to getting it working – http://drupal.org/node/328355
• Table of contents
• Functionality: Filter to turn a token into a TOC, with all the h tags as contents.
• Limitations: Hard to get working with pearwiki. Ended up submitting a patch to use an alternative token.
• Footnotes

• Functionality: Turn in-place markup into a set of footnotes.

Modules I evaluated but did not use

• Flexifilter – Does not actually work. Used pearwiki instead.
• Free Linking – Did not seem to add functionality on top of pearwiki & wikitools.
• Liquid – No D6 version.
• Subscriptions – UI is even more complex that Notifications, which I used instead.
• Quicktags – No D6 version. Used BUEditor instead.
• markItUp – D6 is in dev, not sure how to customize. Used BUEditor instead.
• FCKEditor – Interesting plugin allows it to export Mediawiki syntax, but too complicated. use BUEditor instead.

• Template Filter – No D6 version.