TiddlyWiki - a non-linear personal web notebook
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.
wikidPad - wikidPad is an application for storing thoughts, ideas, todo lists, contacts, or anything else that user can think of to write down.
Wiki on a Stick - Self-contained desktop wiki
Knowledge Workshop - Learning Management Solutions provides innovative and reliable software for the knowledge worker.
ZuluPad - ZuluPad is a notepad on crack.