From: http://www.gersic.com/zulupad/index.html

  ZuluPad is a notepad on crack. It's a place to jot down class notes, appointments,
  to-do lists, favorite websites, annotated bookmarks, pretty much anything you can 
  think of. The great thing about ZuluPad is that it combines the best parts of a 
  notepad with the best parts of a wiki, a concept made popular by Wikipedia. 
  The basic idea has been called a personal wiki or a desktop wiki.

From: http://zim-wiki.org/

  Zim is a graphical text editor used to maintain a collection of wiki pages. Each 
  page can contain links to other pages, simple formatting and images. Pages are 
  stored in a folder structure, like in an outliner, and can have attachments. 
  Creating a new page is as easy as linking to a nonexistent page. All data is 
  stored in plain text files with wiki formatting. Various plugins provide additional 
  functionality, like a task list manager, an equation editor, a tray icon, and support 
  for version control.

From: http://c2.com/cgi/wiki?DesktopWiki

  A wiki that runs as a desktop application. It doesn't require a Web server or 
  any kind of administrative setup. It just works for the end user.

From: http://moinmo.in/DesktopEdition

  Windows:
  Download & install Python
  http://www.python.org/download/ (we recommend Python 2.5 or 2.6)
  the installer will automatically associate .py files with Python.
  Simply double-click wikiserver.py in the Moin folder.