Metal Gear is a popular video game franchise, selling over 30 million units since its inception in 1987. Created by Hideo Kojima and both developed and published by Konami, this series of stealth-based games follow the exploits of special forces agents, most notably the protagonist Solid Snake, and their attempts to protect the world from the Metal Gear superweapon. The franchise includes over 20 video games across various platforms, including the original series for the Japanse MSX home computer and Nintendo Entertainment System, the Solid series and its spin-offs for various home consoles and the PC, and the Acid series for the PlayStation Portable and mobile phone. The franchise also includes various non-game merchandise such as comic books, novels, dramatizations, action figures and toys, and musical albums.