Stylizer - A productivity-focused real-time CSS editor for serious web developers. Mac OS X and Windows.
Notepad++ - A free source code editor which supports several programming languages running under the MS Windows environment.
EnjoyCSS - CSS generator for rich graphical styles without coding
Notepadqq - Notepadqq is a linux clone (identical application) of Notepad++
Rapid CSS Editor - Rapid CSS editor is quick, powerful and easy to use HTML and CSS code editor for web developers. Intuitive interface and intelligent features help you become more productive and create modern HTML5 and CSS3 based websites faster and easier.
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.