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.
Scribes - A text editor for GNOME that combines simplicity with power.
Notepad++ - A free source code editor which supports several programming languages running under the MS Windows environment.
Big Huge Labs Writer - Writer is a free online distraction free writing environment provided by Big Huge Labs.
CotEditor - Open Source Plain-Text Editor for OS X
Caret - Better Markdown Editor for Mac / Windows / Linux