Welcome to the Reference and Books directory, a collection of links on the written word. Despite the explosive growth of electronic media, television, film, and other formats for communication, books hold a place of their own. For centuries, books have been a source of information, entertainment, and opinion. Though writing systems have been in place since before the rule of the Egyptians, it was only after movable type was automated and popularized that books could be created in mass. This was thanks to the development of the mechanical system of Johannes Gutenberg in the 1440s. No longer would manuscripts need to be copied by hand so that the printed word could be shared. Instead, precise replications could be made in large numbers. When the printing press became powered by steam and then by other sources of energy in the 19th century, the cost of producing texts dropped even more dramatically, allowing the written word to proliferate throughout the world. Today, books are written and sold on every conceivable subject, and in our subdirectory, we address some of the major interests you might have. In addition to listings of particular genres, such as fantasy, sports, and society, we also focus on the medium itself. E-books are growing in popularity as handheld device software and reading gadgets are designed to duplicate the experience of paging through a physical book. These types of advances may help to preserve books as a form of expression as the world progresses through the digital age.