Stylizer - A productivity-focused real-time CSS editor for serious web developers. Mac OS X and Windows.
Balthisar Cascade - Balthisar Cascade cascading style sheet editor will make learning and producing CSS easy!
EnjoyCSS - CSS generator for rich graphical styles without coding
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.
CSSEdit - Design beautiful, innovative and fast-loading web sites… with a beautiful, innovative and fast app.
BlueGriffon - An HTML editor based on Mozilla rendering engine.