melonDS v0.3 is released. melonDS is an open source Nintendo DS(NDS) emulator. melonDS is part of a second wave of DS emulators. There are a few other emulator projects that are part of it, which you might have already heard of. Either way, check them out!

melonDS Features:
* almost-complete 2D graphics
* 3D graphics (software renderer) with texturing, alphablending, lighting
* input: keyboard and joystick, touchscreen
* backup memory
* booting from the BIOS
* resizable video output window, preserving aspect ratio of individual screens

melonDS Changelog:
• set POSTFLG when booting games directly, fixes Pokémon games and likely others
• fix bug with cart DMA, booting a game from the firmware should be stable now
• better emulation of cart transfer delays
• better save type heuristics
• support for writing to VCount
• 2D: fix display capture blending modes
• 2D: implement X-flip for bitmap sprites (oops)
• 3D: fix mode3 (vertex) texcoord generation (Eledees no longer looks like your TV decoder broke)
• 3D: fix Z-buffering
• 3D: attempt at fixing culling, works better
• 3D: latch all rendering-related registers upon VBlank
• 3D: delay rendering start a bit, for games that run late
• 3D: optional threaded renderer
• 3D: change renderer to work per-scanline; accurate stencil buffer
• 3D: fix alpha calculation when alphablending is disabled via DISP3DCNT
• 3D: fog and edge marking
• wifi: more functionality emulated, attempt at sending/receiving data
• misc bugfixes and optimizations
• better framerate limiter

How to use
melonDS requires BIOS/firmware dumps from a DS. You can dump them with the following dumper.
The files must be placed in the same directory as the melonDS executable, as follows:
* bios7.bin -- ARM7 BIOS, 16KB
* bios9.bin -- ARM9 BIOS, 4KB
* firmware.bin -- firmware, 256KB or 512KB

Note: the DS-mode firmware in the 3DS isn't bootable. It only contains the bare minimum required to run DS games. Be sure to enable direct game boot when using a firmware dump from a 3DS.

Settings
Emulation: settings related to emulation. For now it lets you enable direct game boot (directly runs the game instead of going through the firmware).
Input: allows you to configure keyboard and joystick input. You can change a mapping by clicking the corresponding entry, then pressing a keyboard key or joystick button. For now, joystick input uses the first joystick available if multiple joysticks are plugged.

Download: melonDS v0.3
Source:Here