OneNote - Get the OneNote app for free on your tablet, phone, and computer, so you can capture your ideas and to-do lists in one place wherever you are. Or try OneNote with Office for free.
ConnectedText - ConnectedText is a powerful but simple information management system.
Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
TiddlyWiki - a non-linear personal web notebook
NoteLedge - Multimedia Notepad , Stay Organized and Make Beautiful Notes
wikidPad - wikidPad is an application for storing thoughts, ideas, todo lists, contacts, or anything else that user can think of to write down.