Zim - a desktop wiki
Here is another desktop wiki.
‘Zim is a WYSIWYG text editor written in Gtk2-Perl. It aims at bringing the concept of a wiki to your desktop. For example every page is saved as a text file with wiki markup. Pages can contain links to other pages, and are saved automatically. Creating a new page is as easy as linking to a non-existing page. This tool is intended to keep track of TODO lists or serve as a personal scratch book. ‘
Check it out here