RedLightGreen is a catalog of the resources of numerous research libraries, archives, and the like that allows you to find and cite books automatically. (RLG is primarily geared to books at the moment, and the site claims that it searches through 120 million of them.) It's true that by now there are myriad ways to accomplish this thanks to WorldCat, RefWorks, and others, but RedLightGreen sets itself apart in enough ways to make it a useful companion to all of these.
For example, you can add resources you've found to a list and have them automatically cited according to the style you specify. Once you've run a search and found something relevant, you can add that resource to a bibliographic list with a single click. You don't need to export the list to RefWorks and login there in order to continue working with your citations; all of it is handled within RedLightGreen. This makes generating bibliographies much simpler. RLG also makes it easy to distinguish between multiple editions of a book. This allows you to be certain that you're citing the book that you're actually using.
Note that RLG isn't a substitute for WorldCat or Taylor's own catalog. That is, you can't directly search these catalogs for resources you've found through searching RLG. (There is a "Get it" link that is displayed next to search results, and it can search Taylor's catalog if you tell it too, but the results are often more confusing than helpful since it displays results from every PALNI library, not just Taylor.) Once you've found something useful there, you'll still need to search for it in Taylor's catalog or WorldCat. Similarly, you can't submit interlibrary loan request through RLG, either; that has to be done through WorldCat, too.
Still, it's a useful complement to our existing catalogs, as you can find and cite most books in what amounts to a single step.
