Luciferin and luciferase are just terms referring to a substrate, or the molecule which an enzyme acts upon, and the enzyme, respectively, which are responsible for the bioluminescent reaction in an organism.  The specific luciferins and luciferases vary.  The terms’ derivative means light bearer.

One cool story I’ve heard about bioluminescence was about a scientist trying to understand GFP, or green fluorescent protein. The Green Florescent Protein was discovered in a marine lab.  The guy was trying to find the fluorescing protein in jellyfish, but it wouldn’t fluoresce in the lab as much as he tried.  Then, one day he went to leave the lab and, as he turned out the lights, he saw his waste bucket glowing.  As there was sea water in it, he slowly realized that the key lied in the fact that there was a lot of calcium in the sea water and that it was key to the fluorescence.