AxKitXspWiki -- a wiki written using AxKit. Pages may be edited in WikiText (currently broken), POD (Perl documentation) or custom XML using stylesheets. For example, here's a wiki page written using a custom schema (an "person" entity) and XSLT stylesheets: http://crew.ccs.neu.edu/wiki/CrewPeople -- IanLangworth
OpenWiki -- http://www.openwiki.com -- XML/XSL architecture. ASP code. Excellent tool. I'm using it at work right now, and love it. My only gripe is I can't get co-workers to understand the WikiEssence and start using the damn thing! :( -- DaveCantrell
OpenWiki -- I'm using OpenWiki too at http://www.jediwars.com/lotr for a Lord of the Rings Wiki. Reformating for XSL is a snap, and love the subpaging and dbl-click-to-edit features. Also multiple choices for backend databases was refreshing. -- BryceNielsen
PerspectiveWiki -- XML/XSLT with WYSIWYG editing across multiple browsers. Incoming messy HTML from browsers is normalised into an XML form for storage.