Does anyone know of a half-way decent FOSS alternative to Kega Fusion?

To start off, I just want to say that Kega Fusion is a wonderful emulator for pre–Sega Saturn emulation. However, the fact that it is not open-source concerns me. What if something happens and the person is required to take it down? (Not likely after 14 years but still...) Or hell they just decide to take it down for whatever reason. (Again, not likely after 14 years, but still...)

I still am using it, but it would also be nice to have an alternative if the worst were to happen, or hell just in case there's a person out there who would prefer a different emulator.

Unfortunately, the Megathread is kind of...lacking in this department. In the Sega subsection, it lists three emulators: two for the Dreamcast and one for the Genesis / Mega Drive and below.

So, yeah, does anyone know of any alternatives we could add to the Megathread?

(On the same note, I'd also like to add that Yabause seems a decent enough emulator for the Saturn, none of for which are included on the Megathread. (Not sure if my syntax was correct there... :/ ))