The chemiluminescence properties of firefly luciferin were studied, in a variety of chemical systems different from those in which it is usually studied. It was found that luciferin is a multifunctional chemiluminescence molecule, as it can behave as a chemiluminescence sensitizer, an emitter and a substrate. The first two roles are here reported for the first time, while we have found a novel way of obtaining excited state oxyluciferin from luciferin. Evidence was also found that does not support the newly proposed radical-mechanism of the formation of firefly dioxetanone. With this study we hope to open the way for novel chemiluminescence applications for firefly luciferin.