Abstract: A fluorescent lighting enclosure system is disclosed which is designed to receive standard fluorescent strip lights of one or multiple lamp configuration and to support and enclose the fixtures in a readily adaptable form. The enclosure is in the form of continuous extrusions having internal tracks extending longitudinally along the full length of the extrusion. A novel spline is designed to fit in the tracks and act as a mount for the enclosure itself and for the fluorescent strips as well as to join the ends of enclosure sections and hold an end plate in place. The enclosure may be mounted with its light emitting opening directed in any direction including inverted. Perimeter lighting, grid and handrail lighting are all possible employing this invention with virtual 100% linear coverage using standard fluorescent fixtures.