DGen is a free, open source and portable emulator for Sega Genesis/Mega Drive systems.
- Game Genie/Hex codes support
- PAL/NTSC, fullscreen modes
- Joypad/joystick and mouse support
- Highly configurable controls
- OpenGL textured video output
- Portable (64-bit, endian-safe)
- Screenshots, demos recording and playback
- Debugger with M68K and Z80 support
- hqx and scale2x upscaling filters
- VGM dumping
- Low CPU usage on current hardware
Runs pretty well. It's definitely good in my opinion (no noticeable errors/bugs). It'd be nice if there was an Android/iOS port though.