CrabEmu is a SG-1000 Emulator and a SEGA Mega System Emulator for Linux, Mac OS X and even the Dreamcast for those whole still have a Dreamcast lying around.
The main focus of CrabEmu was to develop a fast and effective emulator for SEGA’s two 8-bit consoles, the SG-1000 and the SEGA Master System. Unlike most emulators though, this emulator is not available on Windows Operating systems. CrabEmu boasts quite a high compatibility rate while also managing to retain performance, and also include the ability to be able to render the SG-1000 and SEGA Master System’s graphics at a much higher resolution then they were ever intended to be rendered at.
While development of Crab Emu has ceased, its core has now been implemented into the Mac OS X OpenEmu project to handle support for the SEGA Master system.