This is a port of Genesis Plus, an open-source & portable Sega Mega Drive / Genesis emulator, originally developed by Charles MacDonald, now running on the Gamecube and Wii through libogc & devkitpro.
Please note that this project is actually more than a simple port and the original core has been slightly modified: with respect to the initial goals, I focused myself on improving the emulator accuracy & compatibility, as well as implementing new useful features and adding support for extra peripherals / cartridge hardware.
The result is that Genesis Plus is now extremely close to the real hardware, can run the entire Sega Genesis / Mega Drive game library and has nothing to envy to the most popular emulators on the PC platform.
The generic (multi-platform) code is maintained through the SVN repository so that other Genesis Plus ports can take advantage of it, and I sincerely hope this emulator can become a reference for open-source and accurate Genesis emulation. If you want to port this emulator to other platforms or have any questions about Genesis emulation, feel free to contact me

Change log (1.7.4):
Changelog for 1.7.4:
[Core/SCD]
---------------
* fixed access to read-only registers on Main-CPU side ('Batman Returns' platform level freeze)
* fixed & improved emulation of PRG-RAM write protection register ('Lunar Eternal Blue' japanese version freeze)
* improved SUB & MAIN-CPU synchronization ('Dracula Unleashed' freeze when using US Model 2 BIOS)
* improved CPU polling detection
* improved CDD emulation & added CD drive access time for SEEK command ('Panic!/Switch' intro missing scene)
* added missing reinitialization of MAIN-CPU PRG-RAM bank on reset
* added .OGG audio tracks support through LIBTREMOR
[Core/Sound]
---------------
* fixed YM2612 configurable DAC depth emulation
* improved Low-Pass filter
* added optional 'MONO' output mode
[Core/VDP]
---------------
* fixed FIFO access timings when using invalid write code value ('Clue' menu)
* fixed DMA Copy with undocumented code value ('Fatal Labyrinth' end sequence)
* minor code fixes & optimizations
[Core/CPU]
---------------
* optimized 68k stack read/write functions
* fixed broken 68k address error emulation
* fixed 68k interrupt behavior (prevents interrupts from being executed multiple time when 68k is halted)
* fixed Z80 registers initial state, added proper initialization when using PBC (verified on real hardware by Charles McDonald)
[Core/MD]
---------------
* fixed SRAM incompatibilities between BIG ENDIAN & LITTLE ENDIAN platforms (note: this breaks old .srm files with LITTLE ENDIAN platform ports)
* added support for a few recently dumped unlicensed games
* added auto-detection of byte-swapped ROM files
[Gamecube/Wii]
---------------
* fixed CD Leds positioning when using NTSC filter
* improved on-screen CD Leds (thanks to Iceknight)
* various code fixes & improvements