Fetchnotes - Fetchnotes helps you capture and organize short notes like books to read, ideas and shopping lists...
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.
Banana Dance Wiki/CMS - Free open source software combining the best of wiki and CMS with community building-features.
Wiki on a Stick - Self-contained desktop wiki
TiddlyWiki - a non-linear personal web notebook
MyInfo - MyInfo is the most versatile organizer for Windows