PPSSPP is an open source PlayStation Portable (PSP) emulator for Windows, Mac OS X, Linux, and Android.

From the PPSSPP homepage:

PPSSPP can run your PSP games on your PC in full HD resolution, and play them on Android too. It can even upscale textures that would otherwise be too blurry as they were made for the small screen of the original PSP.

Downloads Windows Mac OS X Linux Android
Download page
Latest Builds - Not Stable Releases! (Old → New) Size Date Uploaded (DD/MM/YY)
ppsspp-20140827-macosx.tar.bz2 9.99 MiB 02/05/21 03:39:43