MelonDS (DS)

MelonDS is one of the best Nintendo DS/DSi emulators, rivaling DeSmuME. Developed by Arisotura and a team of contributors, this open-source emulator is even able to emulate Wi-Fi and local multiplayer capabilities and is even available as Libretro core.

This free emulator features more simplified options and UI that is friendlier to those who are new to emulation. MelonDS can run games at a higher internal resolution to provide sharper 3D objects and more vivid graphics, can open ROMS inside compressed archives, and can display the two screens with a wide variety of orientations including a hybrid mode.

The developer Arisotura (formerly known as StapleButter, and Luigi__) is a former contributor to the popular DeSmuME. Although melonDS wasn't the first NDS emulator to have working Wi-Fi capabilities, it is the only emulator, as of the time of this writing, to have gone far with its progress. This emulator does not have any built-in alternate BIOS/firmware. Hence, users are required to provide their own BIOS and firmware dumps and NAND images from a DS to emulate games.

MelonDS is known to work reasonably well with most commercial games. But if you're having some performance issues, switching to OpenGL in the core options usually gives a performance boost.