Nintendo lawyers have successfully patented the emulation in software of handheld gaming devices, with the company already beginning to challenge emulator developers to cease their activites.
Nintendo's patent was filed in November 2000 but only granted on 6th January this year. The filing outlines a "software emulator for emulating a handheld video game platform on a low-capability target platform". Emulators targeting the GameCube, such as they are, are not covered by the patent.
Canadian mobile software developer Crimson Fire has been the first victim of the patent with its Game Boy Advance emulator for Tapwave's Palm OS-based Zodiac handheld console already receiving a 'cease and desist' letter.
Source: The Register