This Wiki is done using JSP technology, which hopefully makes it very easy to keep up to date and looking better than most of the Wikis based on the original one. A custom bean handles the translation of text into HTML.
If you are interested in the JSPWiki development, the home page for JSPWiki is at http://jspwiki.apache.org. Some quick links:
Happy hacking, and thanks for choosing JSPWiki! — Janne Jalkanen