Amazon purchased IMDb, the Internet Movie Database, way back in 1998. IMDb is the repository of all film/television industry metadata--actors, directors, writers, various crew members. It is astoundingly deep; uncredited roles show up on IMDb, as do weird public access shows, the most minute parts in independent productions seen by a few dozen people. Amazon has been updating IMDb from its era as a simple collection of lists; it's not one of the best places to watch movie trailers, for example. But X-Ray is easily my favorite implementation of IMDb's huge amount of data.