dgen is a free, open source emulator for Sega Genesis/MegaDrive systems. The latest version supports save states, interlace mode, Game Genie, Linux joystick support, compressed ROM images, and other nice features.
new maintainer!
After a few years of hosting, maintenance and a new logo, I passed the maintenance flame to zamaz in 2011, long live DGen!
New home: http://dgen.sourceforge.net/