A port of Mesen, a Nintendo Entertainment System emulator to the libretro API
Mesen a relatively new but highly accurate NES emulator. With great accuracy comes great resource requirements (relative to other NES emulators, at least), so this core is not a great choice for weak mobile devices or other low-power/embedded platforms. However, it is the best choice for users who seek the most accurate reproduction of the NES hardware. Mesen also supports some fun enhancements, such as HD sprite replacement packs.