RetroArch is a modular, multi-platform, multi-system emulator.

Major changes in 0.9.8 -> 0.9.9:
- Replaced Zenity launcher script with PickleLauncher
- New default settings, including using GLES video driver by default
- "RGUI" in-game menu, brought up with spacebar by default
You may need to delete (or move to a backup location) /pandora/appdata/retroarch for the new defaults to take effect.

List of included libretro cores:
NES: FCEU, Nestopia, QuickNES
SNES: PocketSNES, SNES9x-Next, Mednafen
GBC: Gambatte, TGB Dual
GBA: VBA, Meteor, Mednafen
Genesis / Sega CD: Genesis Plus, Picodrive (experimental)
Saturn: Yabause (Very slow!)
Playstation: PCSX-ReARMed, Mednafen
Atari 2600: Stella
Chip8/16: Maxe
Arcade: iMAME4all, Final Burn Alpha
VirtualBoy: Mednafen
Neo Geo Pocket: Mednafen
PC Engine: Mednafen
WonderSwan: Mednafen
Cave Story: NXEngine
Doom: PrBoom
Quake: TyrQuake
PC: DosBox
SCUMM: ScummVM
Misc: ModelViewer+SceneWalker (load OBJ 3D models), libretro-2-joy (uinput virtual gamepad)

Also includes RetroArch-Phoenix configuration/launcher GUI (GTK+2 based).
All the cores and RetroArch itself are all the latest git revisions as of the date posted. DeSmuME is included, although it fails a memory allocation at startup on my 256MB unit, in case it might work on 512MB units.
Sources:
- RetroArch (github fork for Pandora): https://github.com/lifning/RetroArch
- RetroArch-Phoenix: https://github.com/Themaister/RetroArch-Phoenix
- Emulator cores: https://github.com/libretro/