You don’t know, you haven’t heard? It’s Yabause version 0.9.10 — the SEGA Saturn emulator for your PlayStation Portable. Now before you get all excited you should know a few things:

1. (Quoted from the readme) PSP support for Yabause is experimental; please be aware that some things may not work well (or at all), and in particular there’s no configuration interface yet.
2. You must obtain the SEGA Saturn BIOS yourself; a simple Google Search will turn that up.
3. You need a PSP-2000 (Slim) or later; Yabause needs the extra ram.

I tried it; it’s semi-functional in terms of loading CD images and playability. Things get choppy, but nonetheless, Yabause clearly demonstrates the possibility of SEGA Saturn emulation. Check the compatibility list here.