It may not be best to extend Markdown for use on a Wiki, because Wikis have special needs.
From: [[Markdown Conflicts]]
### Markdown conflicts with Wiki markup
The issue in a nutshell:
1. We escape some tags like < and > tags into HTML entities to get rid of HTML.
2. Markdown escapes the ampersands of HTML entities inside of
3. We can’t use a library like HTMLPurifier for many reasons, but most importantly there are numerous other conflicts which would be introduced.
Looking around, it would probably be okay to implement our own subset of MediaWiki-slash-DokuWiki-slash-PHPWiki-slash-Creole. Our needs are very few.
The current plan is to try switching to a Creole processor and pre-process anyrthing we want to change.
We also considered using a WYSIWYG editor like AlohaEdit or Redactor. I don’t think this is a good idea for a couple of reasons. Mainly I’m worried about bloat in the Recent Changes log. I like lean markup.