Wonder Library is a very rare Sega Mega Drive cartridge which shipped with some variants of the Japanese Wondermega. When hooked up to a Mega Drive connected to the Sega Mega-CD (or a Wondermega), a specific but presently unknown (possibly Sony-made, JVC-made, or Aplix-made) type of book-on-CD can be played. As with other Wondermega-related products, the cartridge features Wonder Dog heavily. It is unknown whether or not any emulator can use a cart-boot feature to run this game (some do support Flux, which works similarly, so it is possible).