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.
Tomboy - Apps/Tomboy - GNOME Wiki!
My Notes Keeper - Home Of My Notes Keeper - My Notes Keeper is the premier note/outliner application for Windows 9x/2000/XP/NT. It allows you to store all of your notes and information in an easy-to-use outline, where you can quickly find what you need.
Turtl - The secure, collaborative notebook
CherryTree - A hierarchical note taking application, featuring rich text and syntax highlighting, storing data in a single xml or sqlite file.
Carnet - Opensource rich text note taking app