The common name for a Cold Cathode Fluorescent Lamp (CCFL). Thus called because, unlike standard "Hot" fluorescents (e.g. The colloquial “neon” light), they require no heating filament. Cold cathodes are many times brighter than the standard fluorescent bulbs while maintaining a much smaller diameter. They also require a much higher voltage to run, and are more reliable due to the lack of a filament.

Cold cathodes have gained popularity of late as the lighting of choice for "case modders", those who enjoy tricking out their personal computer cases. Usually matched up with a window kit, to show off the inside of your r33t system, and to provide an eerie glow in the color of your choice emanating from your case. While actually referring to just the bulb or tube, it usually is used to mean a complete setup, including inverter and power supply ready to be plugged into your standard ATX case.