telepark.wiki is an interactive Wiki with an AJAX-powered hierarchical navigation system and visual editor (WYSIWYG).

The authoring is done in the Web browser itself without the need for any additional software or download. telepark.wiki allows the visual formatting of each page with the convenience of an in-built editor similiar to Microsoft Word.

telepark.wiki offers a tree-type hierarchical navigation to keep one's wiki organized and easy to use. The number of levels in the navigation tree can be limited artificially (e.g. to 3 levels) by way of configuration or can be unlimited. Each page can contain any number of links to other pages for non-linear navigation. Links are created with a visual editor. The reordering of navigation elements is done by drag-and-drop. Right-clicking on a navigation element opens a context menu, just as in Windows Explorer, to add new pages or delete existing pages.

You can either allow anyone to edit your wiki or require a password. In case of password-protected editing, the user simply double-clicks on the navigation tree's first node (the root node) and a password entry-field is shown. Upon entering the correct password, the user is "logged-in" and can now double-click each navigation element to start editing a page.

More information you can find at http://www.telepark.com