melonDS is an open-source emulator that runs original Nintendo DS and DSi games on modern operating systems with high-accuracy hardware simulation. It emulates the DS and DSi CPUs, video, and audio systems, and supports booting from original system firmware for access to the system menu and configuration screens.
The emulator distinguishes itself through cycle-accurate component simulation for precise timing and compatibility, a JIT dynamic recompilation engine that translates game code to native x86_64 or AArch64 instructions for faster performance, and OpenGL hardware-accelerated rendering with programmable shaders and texture upscaling for improved visual quality. It also provides DSi extended hardware emulation including the DSP, audio channels, and expanded memory registers, a GBA slot passthrough interface for add-on accessories like the link cable and rumble pack, and network-transparent multiplayer bus that synchronizes multiple emulator instances over UDP packets for local network multiplayer sessions.
Additional capabilities include savestate serialization for capturing and restoring the complete emulator state, cheat code importing from standard usrcheat.dat files, real-time clock and microphone emulation, joystick input support, and adjustable dual-screen display layout and rotation configuration. The emulator also supports audio output synchronization with blip-buf resampling for low-latency playback.
