Brackets - A modern, open source text editor that understands web design
Turtl - The secure, collaborative notebook
Atom - At GitHub, we’re building the text editor we’ve always wanted: hackable to the core, but approachable on the first day without ever touching a config file. We can’t wait to see what you build with it.
Tomboy - Apps/Tomboy - GNOME Wiki!
Sublime Text - Sublime Text is a sophisticated text editor for code, html and prose - any kind of text file. You'll love the slick user interface and extraordinary features. Fully customizable with macros, and syntax highlighting for most major languages.
Carnet - Opensource rich text note taking app