From wikipedia:
Neko Project II is an open source emulator that runs on Windows, OS X, and even PSP.
Homepage (source available here): http://www.yui.ne.jp/np2/indexe.html
PSP port: http://files.pspupdates.qj.net/cgi-bin/cfi...0,0,0,0,46,1489
PSP port source...