TiddlyWiki - a non-linear personal web notebook
Woas - Complete wiki in a single HTML file, forked from Wiki on a Stick.
Zim Wiki - 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.
ZuluPad - ZuluPad is a notepad on crack.
ConnectedText - ConnectedText is a powerful but simple information management system.
wikidPad - wikidPad is an application for storing thoughts, ideas, todo lists, contacts, or anything else that user can think of to write down.